lApplying Your Knowledge

Transcription

FIRST EDITION
Cambridge Physics Outlet
Peabody, Massachusetts 01960
The cover is an evocative montage of historic scientific achievements that demonstrate the incredible persistence of the
human intellect. Around the border, DaVinci’s graphics represent the start of an evolving tapestry of conceptual thinking.
His fantastical mechanisms become the modern bicycle, a quintessential machine, which rolls into a graphical
interpretation of wavelength division multiplexing on a fiber optic. These images follow 500 years of scientific and
technological innovation. The Earth and DNA serve to remind us that this technological innovation will always remain
deeply connected to the natural world. On the back cover, the elegant geometry of the chambered nautilus folds into a spiral
defined by the Golden Rectangle. The interplay of organic and architectural forms represents the balance we seek between
the power of technology and the fragility of our lives and our world. I hope this colorful interplay of images will inspire
interest and excitement about the discovery of science.
Bruce Holloway - Senior Creative Designer
Foundations of Physical Science
Teachers Reference Guide
Copyright
2002 CPO Science
ISBN 1-58892-019-4
3 4 5 6 7 8 9 - QWE- 05 04
All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including
photocopying and recording, or by any information storage or retrieval system, without permission in writing. For permission and other rights
under this copyright, please contact:
CPO Science
26 Howley Street
Peabody, MA 01960
(800) 932-5227
http://www. cpo.com
Printed and Bound in the United States of America
CPO Science Development Team
Tom Hsu, Ph.D. – Author, President
Scott Eddleman – Curriculum Manager
Irene Baker – Senior Curriculum Writer
Ph.D., Applied Plasma Physics, Massachusetts Institute of
Technology
B.S., Biology, Southern Illinois University; M.Ed., Harvard
University
B.S., Chemistry, B.S., Humanities, MIT; M.Ed., Lesley University
Nationally recognized innovator in science and math who
has taught in middle and high school, college, and graduate
programs. Personally held workshops with more than
10,000 teachers and administrators to promote teaching
physics using a hands-on approach. CPO was founded by
Dr. Hsu to create innovative hands-on materials for teaching
math and science.
Taught for thirteen years in urban and rural settings;
nationally known as a trainer of inquiry-based science and
mathematics
project-based
instruction;
curriculum
development consultant.
Lynda Pennell – Educational Products and Training,
Vice President
B.A., English, M.Ed., Administration, Reading Disabilities,
Northeastern University; CAGS Media, University of
Massachusetts, Boston
Nationally known in high school restructuring and for
integrating academic and career education. Has served as
the director of an urban school with seventeen years
teaching/administrative experience.
Thomas Narro – Product Design, Vice President
B.S., Mechanical Engineering, Rensselaer Polytechnic Institute
Experience is in scientific curriculum development, in
educational research and assessment, and as a science
consultant.
Bruce Holloway – Senior Creative Designer
Laine Ives – Curriculum Writer
Pratt Institute, N.Y.; Boston Museum School of Fine Arts
B.A., English, Gordon College; graduate work, biology, Cornell
University, Wheelock College
Expertise is in product design, advertising, and threedimensional exhibit design; winner of National Wildlife
1999 Stamp Award.
Experience teaching middle and high school, here and
abroad, and expertise in developing middle school
curriculum and hands-on activities.
Mary Beth Abel – Curriculum Writer
B.S., Marine Biology, College of Charleston; M.S., Biological
Sciences, University of Rhode Island
Taught science and math at an innovative high school; has
expertise in scientific research and inquiry-based teaching
methods.
Erik Benton – Professional Development Specialist
Polly Crisman – Graphic Designer and Illustrator
B.F.A., University of New Hampshire
Graphic artist who has worked in advertising and marketing
and as a freelance illustrator and cartoonist.
Patsy DeCoster – Professional Development Manager
B.S., Biology/Secondary Education, Grove City College; M.Ed.,
Tufts University
Curriculum and professional development specialist. Taught
science for twelve years. National inquiry-based science
presenter.
Accomplished design and manufacturing engineer;
experienced consultant in corporate re-engineering and
industrial-environmental acoustics.
B.F.A. Universty of Massachusetts
Thomas Altman – Teaches physics at Oswego High
Gary Garber – Teaches physics and math at Boston
Catalina Moreno – Taught eight years at East Boston
School, NY, and invented the Altman Method for making
holograms in the classroom.
Julie Dalton – Has worked as a copy editor for major
Boston newspapers. She has also worked as a sports writer
and editor and taught secondary English.
University Academy, and is a researcher at the BU
Photonics Center; past president of the Southeast section of
the American Association of Physics Teachers.
Matt Lombard – Marketing manager, oversees
marketing and public relations activities for CPO; expertise
is in photography of equipment and curriculum materials.
High School as a bilingual science and math teacher. Also
an expert resource for the American Astronomical Society.
David Bliss – Teaches life, physical, and Earth science at
Mohawk Central High School. Has been a teacher for 34
years.
Tracy Morrow – technical consultant
James Travers – illustration and graphic designer
John Mahomet – graphic designer
Dexter Beals – Beals Dynamics
Kent Dristle – physics teacher, Oswego (NY) High
Kelly Story – assessment specialist
Cerise Cauthron – teaching consultant
Debbie Markos – teaching consultant
Jeff Casey – experimental physicist
Roger Barous – machinist
Kathryn Gavin – quality specialist
Agnes Chan – manufacturing engineer
Taught for eight years in public and private schools,
focusing on inquiry and experiential learning environments.
Curriculum Contributors
Consultants
Greg Garcia – Spanish glossary
Mike Doughty – intern, Endicott College
Jennifer Lockhart – intern, Endicott College
Product Design
Greg Krekorian, Shawn Greene – production team
Reviewers
Bell, Tom
Curriculum Specialist
Cumberland County Schools
North Carolina
Chesick, Elizabeth
Head of Science Department
Baldwin School
Pennsylvania
Curry, Dwight
Assistant Director of Physical Science
St. Louis Science Center
Missouri
Gharooni, Hamid
Program Director, Math & Science
Madison Park Technical-Vocational High School
Massachusetts
Haas, Jack
Principal Reviewer, Chemistry
Professor of Chemistry
Gordon College
Massachusetts
Inman, Jamie
Physics Teacher
North Carolina
Lamp, David
Associate Professor
Physics Department
Texas Tech University
Texas
Leeds, Susan
Science teacher, eighth grade
Howard Middle School
Florida
Lowe, Larry
Physics and Electricity Teacher
Masconomet Regional High School
Massachusetts
Madar, Robert
Senior Consultant and Trainer
Impact Consulting
Oregon
Nelson, Genevieve M.
Head of Science Department
Germantown Friends School
Pennsylvania
Ramsay, Willa A.
Science Education Consultant
California
Susan Schafer
Principal Investigator
College of Engineering
Texas Tech University
Texas
Scott, Janet
Curriculum Specialist
Durham Public Schools
North Carolina
Les Sewall
Science Education Consultant
Georgia
Tally, Michael
Science Supervisor
Wake County Public Schools
North Carolina
Texas, Leslie A.
Senior Consultant and Trainer
Impact Consulting
Kentucky
Thompson, Gaile B.
Director of Science Collaborative
Region 14 ESC
Texas
Woodring, Kathleen
Physics Teacher
Industrial High School
Texas
The CPO Science Program
“The whole of science
is nothing more than a
refinement of everyday
thinking.”
The CPO Science Program correlates directly to state standards
Introduction
One of the great scientists in history, Albert Einstein stated, “The whole of science is
nothing more than a refinement of everyday thinking.” This great thinker and theorist
explained that science is not just the memorization of complex facts or the rote learning
of complicated ideas but a process by which we discover and explore the things,
Albert Einstein
concepts, and mysteries we see around us.
The CPO Foundations of Physical Science Program is created from the premise that
science is an exploration and discovery of ideas about the universe, and that ideas and knowledge connect and enhance our
lives. The program is presented and sequenced in a way that moves the student through an inquiry-based learning approach.
Each chapter and Investigation begin with key questions that form the foundation for the learning. In many sections, student
complete experiments and hands-on activities before conceptualizing ideas in the student readings. Threaded throughout all
the instruction are probing questions that students answer through exploration, posing new questions, finding data to prove
theories, and expressing their findings to others.
Unlike other textbooks that match content to National Science Education Standards, the CPO Science Program was written
directly to your state standards. The standards form the benchmark criteria from which each science topic, specific content
requirement, and science process was developed. The program provides numerous opportunities for students, teachers, and
schools to meet the standards and state testing program. Matching the standards to CPO Unit topics ensures that students will
receive the highest quality in science instruction to the depth and breadth necessary to meet your teaching needs.
Your state correlation index is included in this reference volume and demonstrates the alignment between the state standards
and the CPO Science Program. The index lists specific page numbers from the CPO Student Edition and Investigation Lab
Manual where examples of correlations are found. An example of the CPO Scope and Sequence guide also found in the
teacher’s guide demonstrates the careful consideration and detail of content match between the Student Edition and
accompanying Investigations. These charts can be reviewed as a quick reference to the teaching and learning objectives
covered in this program.
Meeting all students’ needs
Learning science is an active process allowing students to gain abstract, conceptual knowledge through discovery. Most
students learn best when reading is enhanced by doing. The CPO Science Program combines strong, in-depth coverage of
physics and chemistry content with abundant hands-on learning activities to meet the variety of learning styles. Real-world
examples and historical perspectives provide students the authenticity that validates their connection to the content and
topics. Teaching tips are found in the teacher’s guide as suggestions for remediation and skill development practice with
challenge problems for students who are prepared to tackle more difficult concepts.
i
Introduction
The Multilevel Classroom of Today
Classrooms are composed of learners who are at different instructional levels and who process information through multiple learning styles.
The CPO Science Program has been designed to meet the challenge of bringing in-depth, accurate science to all students. To teach in-depth
science concepts and skills, the design of the Student Edition reflects instructional aids and strategies to meet that diversity of student needs.
Careful consideration has been taken to include reading, math, and learning techniques to help all students grasp science concepts and skills.
Reading and concept-learning strategies
Main idea indicators — Main idea indicators appear in the left margin of each paragraph in the Student Edition to help students find
information and understand the main concepts in the instruction. Students can use the indictors in the following ways:
• Read all the main idea indicators before reading the section as a pre-reading activity.
• List the major points of the section.
• Create outlines and concept maps.
• Find answers to questions by skimming and scanning the indicators for a quick review.
Highlighted vocabulary — As in any discipline or occupation, people must understand the subject’s terminology and know how to use it
correctly. Terms, units of measurement, and concepts are highlighted in blue for students to easily identify key words as reading clues and for
vocabulary development.
Bold highlighted points — Major scientific concepts, vocabulary, and laws appear in large print and blue type. These statements identify the
major learning points and what to review when studying.
Building problem-solving skills by using key questions
Asking questions before starting an activity focuses students on what they will learn during the experiment or reading. Each Investigation
begins with a key question that students need to answer after the activity. Students build problem-solving and critical thinking skills as they
tackle each Investigation question. The following is a suggested sequence to use when deciphering questions:
• Have the student reread the question.
• Underline the action words and explain what is being asked.
• Identify the important words (usually vocabulary words).
• Have the students rewrite the question in their own words.
• Help students decide what they will need to know in order to answer the question.
ii
Introduction
Reading illustration and graphics for science concepts
Some students learn best through visual clues and illustrations. Others need the dual support of text and visual clues in order to comprehend
science concepts and theories. Our student text and Investigations manual have numerous content-rich illustrations, charts, tables, and
graphics. Suggestions for using the visual clues include:
• Give students enough time to analyze the graphics and illustrations. Decoding the meaning of a visual is like reading text.
• Ask the students to verbally explain what they see in the graphic and what is being demonstrated.
• Teach students to read data tables and graphs so that they understand how to organize and represent data. Numerous examples and
questions requiring completion of tables are presented with explanations.
• In teams, have students illustrate a concept or create graphics for the section. Other team members decide which concept or section is being
illustrated.
Reading, understanding, and using math formulas
Formulas help students describe relationships between quantities. After students understand the basis for formulas and how they represent
relationships, they can use them as tools for solving problems or predicting outcomes. We emphasize understanding relationships rather than
simply memorizing formulas.
• Math formulas are connected to the data collection process during hands-on activities. The formulas are all in the context of the
Investigation, and as a result, students apply math formulas to actual science experiences.
Important math formulas are highlighted, written in large print, and also explained in the text.
• Example problems illustrate how to use the formula and how it can be applied to the most common situations. Students’ learning of the
formulas is reinforced throughout the Student Edition and in the assessment sections.
• Only the most relevant math formulas are presented in the text and explained in depth.
• A reference section in the Student Edition contains an easy-to-read table of all the formulas in the program.
Expressing learning in a variety of ways
Students learn differently and use various avenues for expressing their knowledge. In the review questions in the Student Edition, students
are asked to answer Applying Your Knowledge questions. These questions allow students to express their knowledge and demonstrate
learning in several modalities. Examples include designing an experiment, researching information, building a model, writing an essay,
checking appliances in their homes, preparing a pamphet or brochure, discussing ideas, creating sketches, forming a committee to develop
plans, interviewing someone, creating a handout for young children, and using the Internet.
iii
Introduction
Evaluation and Assessment
The CPO Science Program is committed to presenting material in a variety of ways to meet the diversity
of student learning styles. Students learn in a combination of modalities and demonstrate understanding
through a variety of modes. A combination of evaluation methods is available to ensure multilevel and
diverse opportunities. A variety of methods is necessary in order for students to demonstrate science
content knowledge, application skills, performance abilities, and scientific process and problem-solving
skills to the best of their ability. Below are descriptions of the different evaluation and assessment
instruments.
“Anyone who has
never made a mistake
has
never
tried
anything new.”
Albert Einstein
Evaluating with review questions — formative assessment
Review questions are found at the end of each chapter to evaluate student progress and reflect on key chapter objectives. These questions
provide opportunities to test and practice vocabulary, concept knowledge, skill understanding, computational ability, problem solving, and
application. Many questions require a written response in order to better evaluate the student’s abstract understanding. The review questions
are a useful teaching tool to benchmark individual progress and to aid class discussions that review and reflect on chapter objectives.
Assessing broader knowledge with assessment questions — summative assessment
The assessment questions have been carefully designed to test all the important topics covered in a unit. The assessment questions evaluate the
student’s knowledge that correlates with the unit. Included in the questions are examples of graphs, charts, and computational information
needed to answer questions and demonstrate application skills. The assessment questions are on the Examview CD and consist of multiple
choice and multi-format questions that cover computation, skill attainment, and concept understanding. These questions are designed to reflect
typical standardized test questions. Exposure and practice in answering multiple-choice type questions has proved helpful to students in states
using formal standardized testing. There are over 800 questions on the Examview CD.
Learning and applying skills — performance assessment
Being able to justify conclusions based on active experimentation and data collection is a powerful skill in today’s technological world.
Performance assessment measures how well a student can solve problems and demonstrate understanding through application. The CPO
Science Program builds the self-confidence that students need to tackle problems in a thoughtful and sequenced manner.
An Investigation is completed with each teacher’s guide section and includes questions and activities that allow teachers to observe the
students’ ability to think and demonstrate understanding. Most Investigations rely on team participation and hands-on learning. Students are
continuously exposed to a systematic problem-solving method that encourages students to discover, observe, collect data and justify findings.
A sample observation evaluation form is provided in the Strategies and Tables section of the reference volume to help determine the students’
progress with performance tasks. A student reflection form can be found in the Skills Sheet section.
iv
Introduction
Organization of the Program
“Hear and you
forget; see and you
remember; do and
you understand.”
The program is composed of four components: Student Edition, Investigations, Teacher’s Guides, and
Equipment. These components reflect the connections between inquiry-based learning, hands-on
discovery, and grasping science concepts through reading. Abstract concepts and skill development
opportunities are presented in a variety of ways to address diverse and multiple learning styles. Enhancing
Confucius
the instruction are clear, precise illustrations that reinforce the learning of abstract concepts. By the end of
each section, students have completed a hands-on activity or experiment, answered essential questions, and
mastered science skills and content through reading.
The Teacher’s Guide and support materials have been divided into six volumes: one reference and five content topic guides. The reference
volume contains: the glossary, index, assessment questions and answers, review answer keys, skill sheets, and other reference tables. The
five content topic teacher’s guides provide sample lessons that demonstrate how to teach each lesson with accompanying Investigation sheets
and answers. Teaching tips, challenge questions, and student reinforcement of skills are also present.
Student Edition
The basic organizational structure of the Student Edition is the unit. There are nine units that are broken down into topic chapters containing
three to five content-specific sections. The unit themes covered in the CPO Foundations of Physical Science Program were chosen because
of their relevance to CPO’s commitment to in-depth coverage of science concepts. The glossary and index have been designed so students
can quickly skim for page numbers and definitions. Each student section contains pertinent content and skills-development reading with
numerous illustrations for reading support. Each chapter contains an extensive review question section that evaluates the student’s progress
in areas such as: vocabulary development, concept understanding, computation skills, and application. Special features of the Student
Edition:
• Chapter pages: These introductory pages present the major components of the student reading, including Investigation descriptions, what
the student will learn from the section, and the pertinent vocabulary.
• Side heading outlines: Developing literacy skills in math and reading is stressed throughout the instruction. Left-margin side headings
highlight the main ideas in the text and help the student grasp reading concepts through skimming, scanning, and key word identification.
• Highlighted vocabulary: Science vocabulary mastery is paramount for science concept understanding. Science vocabulary can be highly
technical and abundant. Vocabulary words are highlighted for easy identification and defined in a variety of ways.
• Numerous visual teaching tools: The Student Edition contains graphics, charts, illustrations, and data tables supporting abstract
conceptual learning. These teaching tools reinforce instruction and aid in visual representation of material necessary for addressing
multiple learning styles. The visuals are precise in content and presentation and reflect CPO’s commitment to accuracy, science content
excellence, and inquiry-based instruction.
v
Introduction
Investigations
“The greatest tragedy of
Science: the slaying of a
beautiful hypothesis by an
ugly fact.”
The Investigations are the heart of the CPO Science Program. We believe that most students
learn best and are motivated to learn through direct experience and exploration activities. Key
questions focus the student on the main point of the learning and what they should be able to
answer after the experiment. There is at least one Investigation for each student reading section.
The student reading and Investigation closely compliment the science instruction and reinforce
Thomas Huxley
the same principles.
Each Investigation is introduced with a key question that the students will be able to answer
after completing the hands-on activity. Students are also given learning goals for each Investigation and a short informational piece to get them
thinking about the content of the Investigation. Student answer pages are found in the teacher’s blackline master notebook. The teacher can
duplicate the forms for students to complete and answer the questions.
Each Investigation begins with a key question and uses leading questions to aid in skill development, reflection, and application. An
observation form is found in the Strategies and Tables section of the reference volume to aid the teacher in evaluating Investigations as
performance-based tasks.
Investigations are usually completed before the accompanying student reading section. The CPO philosophy is based on the premise that
through discovery, the students will begin to understand foundation skills and concepts. The student readings strengthen the students’
knowledge of theory and aid in their understanding. For certain Investigations, the student reading must be read first so that students have the
basic knowledge necessary to complete the Investigation. Whether a section should be read before or after an Investigation is explained under
the reading synopsis heading in the teacher’s guide pages for each section.
Special Features
• Data collection, graphing skills and the scientific process: These skills are emphasized and reinforced throughout the program and
students are frequently encouraged to practice these skills as self-learners.
• Lesson planning page: The information you need to know to teach and conduct the Investigation is available in the teacher’s guide section
pages. The learning goals and questions, equipment setup requirements, consumable materials list, teaching sequence, and a synopsis of the
student reading are all in found on the lesson introduction pages.
• Icons: Throughout the Investigations, icons are used to point out safety requirements and to reference important information for the students.
A reference sheet of the icons and the meaning of each is found in the Student Edition and the teacher's guides.
• Equipment: Specialized equipment has been designed to accompany the teaching of the Investigations. The equipment is durable and
provides consistent accurate results.
vi
Introduction
Teacher’s guides
“The most important thing in
science is not so much to
obtain new facts as to
discover new ways to think
about them.”
The teacher’s guides are constructed around the same premise as the student instructional
materials: inquiry-based learning. The guides include a sample demonstration lesson for
each Investigation written as a dialogue between the teacher and the class. These samples
demonstrate how to teach the Investigation using inquiry-based teaching and student group
discovery. The sample demonstration is only one example of teaching the Investigation
with possible student responses. Teaching tips, the accompanying student section synopsis,
projects, and teaching strategies are also included.
William Bragg
The first two pages of each teacher’s guide section contain a clear, concise overview of the
Investigation. It is our belief that a quick guide is useful in outlining the learning objectives, setting up the Investigation, and mapping the
sequence of the Investigation procedures. These pages contain a brief synopsis of the student reading, review of the leading question,
learning objectives, and a clear equipment and consumable materials list. The equipment setup instructions are identified with an equipment
icon and are found in this volume under the Equipment Setup section.
The Investigation lesson pages present a sample teaching scenario written as a dialogue between the teacher and class. The dialogues present
actual lessons taught from the teacher’s point of view, as well as possible student responses. The dialogues provide excellent support for
teachers who are new to the subject area, as they identify possible student misconceptions and highlight important learning content. The
dialogues provide teaching tips such as:
• What to put on the chalkboard.
• How to teach by questioning.
• What reactions the students may have and how to respond.
• Interesting stories to make connections between key concepts and
everyday life.
• Computational information.
Organization of the teacher's guides
The teacher’s guides are divided into five unit volumes and the reference volume. The volumes have been divided according to similar
objectives, content coverage, and specific equipment needs. The lightweight topic volumes are easy to carry and content is focused on one to
three units. You will only need one volume and the reference section when planning a lesson. The teacher’s guides contain the Student
Edition text and all the information you need to teach and evaluate each unit. The reference volume includes: assessment questions and
answers, quick reference charts, teaching information, the glossary and index. The unit contents for the teacher’s guides are:
Volume 1: Reference volume
Volume 4: Sound and Waves, Light and Optics
Volume 2: Force and Motion, Work and Energy
Volume 5: Properties of Matter, Changes in Matter, Water and Solutions
Volume 3: Electricity and Magnetism
Volume 6: Heating and Cooling
vii
Introduction
Equipment
CPO products are high-quality, accurate, and long-lasting. These characteristics are found in all
the equipment used to teach the concepts in the CPO Science Program. Equipment has been
especially designed and tailored to the course goals and tested to ensure precise data and
repeatable findings.
You can use the CPO Science Program to its fullest potential by taking advantage of all the
benefits of using hands-on equipment. There is a section in this book that presents all the
equipment and how to set up and use each piece. Information is presented in the Investigations
that also explains how to set up the equipment and how it will be used throughout the
experiments.
The table below outlines the equipment pieces and units where the equipment is needed.
Equipment Name
Car and ramp
Rollercoaster
Gears and levers
Ropes and pulleys
Electric circuits and motor
Pendulum
Sound and waves
Spectrometer
Light and optics
Periodic table tiles
Displacement tank
Atom Building Game II
Units Equipment is Needed
Unit 1, 2
Unit 2
Unit 2
Unit 2
Unit 3
Unit 4
Unit 4
Unit 4
Unit 5
Unit 6,7
Unit 6
Unit 6,7
“The strongest arguments
prove nothing so long as the
conclusions are not verified by
experience.
Experimental
science is the queen of
sciences and the goal of all
speculation.”
Roger Bacon
Concepts
motion, speed, acceleration, Newton’s laws
energy conservation, transformation, potential and kinetic energy
simple machines, input and output force, mechanical advantage
simple machines, work, energy
voltage, current, resistance, series circuits, parallel circuits
harmonic motion, time, frequency, period, cycle, amplitude
sound, music, frequency, period, wavelength
wavelength, light, color
light, color, optics, reflection, refraction, lasers
the periodic table, chemical formulas, balancing chemical equations
buoyancy, force, weight, mass, displacement
atomic structure, electrons and bonding, atoms, ions, isotopes
*The Timer and the Physics Stand are used with Force and Motion, Work and Energy, and Sound and Waves.
The equipment is available in suggested packages depending on the needs of the school or district. Districts will receive an equipment voucher
that can be used to receive the appropriate equipment package to fit teaching needs. The equipment quantity included in the voucher will
depend upon the number of textbooks a district purchases for its students from the adoption process.
viii
Introduction
Sharing Equipment
Many schools share lab equipment among science teachers. The CPO Science Program has been designed to meet this need with alternative
sequences for teaching the units. The sequences outlined in the chart below allow three teachers to simultaneously teach different units of the
program and share one classroom set of equipment. If the time for each rotation is followed, there is no overlap for any piece of equipment
used in the program.
Each teaching sequence allows for a suggested teaching time period and a week for review and evaluation. The teacher’s guides have been
divided into volumes so that every teacher in the rotation can use the volume they need for the units they are teaching.
Other equipment rotation suggestions include: creating a designated space as a science lab with multiple sets of equipment, and portable
equipment science labs that can be moved from classroom to classroom.
Suggested Teaching Sequence and Rotation of Equipment for Three Teachers
Teacher
One
Teacher
Two
Teacher
Three
Unit 1: Forces and Motion
Unit 2: Work and Energy
Unit 3: Electricity
Unit 9: Heating and
Cooling
Unit 4: Sound and Waves
Unit 5: Light and Optics
Unit 6: Properties of Matter
Unit 7: Changes in Matter
Unit 8: Water and Solutions
8 teaching weeks
1wk review/evaluation
4 teaching weeks
4 teaching weeks
4 teaching weeks
10 teaching weeks
Unit 3: Electricity
Unit 6: Properties of Matter Unit 1: Forces and Motion
Unit 9: Heating and
Cooling
4 teaching wks
4 teaching wks
10 teaching weeks
8 teaching wks
4 teaching weeks
Unit 6: Properties of Matter Unit 1: Forces and Motion
Unit 9: Heating and
Cooling
Unit 3: Electricity
10 teaching weeks
4 teaching weeks
4 teaching weeks
4 teaching weeks
8 teaching weeks
ix
Introduction
How the Volumes Are Organized
Volume 1
Contains introduction, scope and sequence, answer keys to review questions, teaching tools,
equipment setup, and the glossary and index from the Student Edition.
Volume 2
Forces and Motion / Work and Energy
Volume 3
Electricity and Magnetism
Volume 4
Sound and Waves / Light and Optics
Volume 5
Properties of Matter / Changes in Matter / Water and Solutions
Teacher’s guides (white pages) and Student Edition (cream color pages)
Teacher’s guide (white pages) and Student Edition (cream color pages)
Volume 6
Heating and Cooling
Teacher’s guide (white pages) and Student Edition (cream color pages)
x
Introduction
The Teacher’s Guide Investigation Overview Pages
The teacher’s guide for each Investigation begins with the overview pages. The overview pages correspond to each section of the Student
Edition and each Investigation in the CPO Science Program. These pages review the instructional components, beginning with a summary of
what the students will learn in the Investigation. Included are a synopsis of the reading, pertinent vocabulary from the Investigation, learning
goals, and the key and leading questions that students will be able to answer after completing the Investigation. It is important to note that
below the heading for the reading synopsis, there is a suggested sequence for teaching the student section and the Investigation. The student
reading section frequently follows the completion of the hands-on Investigation. In some sections, the student reading must be completed
first in order for students to assimilate the skills and concepts required to complete the Investigations.
The second page outlines the equipment and material needed, teacher’s guide section considerations, and the sequence of teaching steps.
xi
Introduction
Teacher’s Guide Demonstration Lessons
Each teacher’s guide demonstration lesson contains an outline of the lesson, a “sample dialogue,” and teaching strategies and tips. These pages
also include the Investigation and sample answers to the activity. In the facing-page format, you can review the sample dialogue between the
teacher and students, the Investigation page, and sample data and answers. All the information you will need to teach the Investigation is easily
skimmed in this format.
Below are the features of the dialogue, Investigation answer page, and sidebar teacher notes.
Outline: This section contains an at-a-glance sequence of steps that a teacher can skim. It is a quick guide to what is taught in the Investigation
and notes on the Investigation.
Inv.: In this column the teacher will find a reference number that matches the parts of the Investigation page. These corresponding numbers
guide you to the part that is discussed in the dialogue.
Dialogue: This section is presented as an exchange between the teacher and the class. This sample lesson outlines what the teacher would
actually say to the class and typical responses from the students. Helpful teaching ideas and tips such as: “Students will need access to water,”
“Group supervision is important at this point” are included. The teacher’s directions and comments to the students are printed in black, and
responses and directions are in blue text. It is our hope that teachers will review the dialogue before presenting the Investigations to the class,
as a supportive tool and to help clarify the goals and important points of each Investigation.
Investigation: This is a miniaturized Investigation page that is referenced in the dialogue. The Investigation page includes answers to data
tables and written responses. The teacher can refer to the numbers at the left of the Investigation page and match them to the opposite page as
numbers under the column “Inv.” These numbers indicate what section of the Investigation the dialogue is referring to. The data and some of
the reflective answers are only examples of data and responses that can be given by the students.
Reinforcement and Enrichment: This section includes teaching tips, challenge questions, and more reinforcement ideas for students who
may need extra time learning concepts. Ideas for future study and short interesting pieces are also found in this right-hand margin area.
xii
Introduction
xiii
Introduction
Safety
Safety is highlighted throughout the CPO Science Program by the use of safety icons and safety tips in the Investigations. The Investigations
activities and experiments have been written to reduce safety concerns in the laboratory. The equipment that is used for physics is very stable
and easy to use and manage. All the chemistry Investigations use supplies and chemicals that can be purchased readily in a grocery or hardware
store. Although this does not mean that these supplies are non-toxic, you will be able to dispose easily of most of these chemicals. In cases
where you are concerned about safety and proper use or disposal, we strongly recommend that you obtain the Materials Safety Data Sheets
(MSDS) for the chemicals. These are easily obtained by calling the manufacturer of the product.
The CPO Science Program introduces students to safety through an information Safety Skill Sheet. In addition to this sheet, we have provided
a quiz as an evaluation tool to be administered to the students after you have covered safety in the laboratory. We recommend devoting an
entire lesson to safety in the classroom and laboratory and responsibilities for maintaining a safe environment. Use the Safety Skill Sheet as a
guide for your lesson and fill in any information and guidelines that are particular to your classroom and school. In the skill sheet section of this
book you will find a student safety contact. Safety is such a crucial concern when working in a laboratory environment that having students
sign a contract may emphasize that safety in the science lab is everyone’s responsibility.
Units and Measurement
The CPO Science Program was designed to prepare students to be successful in any career, not just academia. Students need to be fluent with
scientific skills in any system of units prevalent in the workplace. Virtually all engineering and industrial careers require proficiency in both
English and metric units. Even metric measures are not standardized. Research scientists use two varieties of metric: meter-kilogram-second
(MKS) for physics and centimeter-gram-second (CGS) for chemistry. Ocean and air transportation industries use nautical miles. Medicine uses
both Fahrenheit and Celsius temperature scales. Astronomers use light-years. The message to take from this diversity is that students need to
learn and practice science in several systems of units because they will encounter different systems outside the classroom.
You will find that the text, examples, and questions gradually transition from mixed English/metric to all metric by the end of Unit 2. Because
of their extensive practical use, the Student Edition and Investigations include both English and metric (MKS) units in Unit 1 (Force and
Motion). This was done to connect the student’s common experience and also to provide a bridge between the systems. For subsequent units,
almost all concepts are presented in metric units, with an occasional reference to other systems when appropriate. All of the assessments use
only metric units, which is common practice for standardized tests. The chemistry units (6-8) switch from MKS to CGS to mirror research,
medical, and industrial chemistry, which is measured predominantly in grams and milliliters instead of kilograms and cubic meters. It is our
opinion that a basic high school science education should be focused on developing practical quantitative reasoning, problem solving, and
observational skills. By presenting a mixture of units as they occur in the real world, we help prepare students for success in any endeavor that
requires scientific thinking, such as business, industry, or education, as well as for further study in science.
xiv
Table of Contents
Reference Guide Sections
Scope and Sequence . . . . . . . . . . . . . .
1
Chapter Review Answer Keys . . . . . . 55
Teaching Tools . . . . . . . . . . . . . . . . . . . . . . 123
Equipment Setup . . . . . . . . . . . . . . . . . . . . 175
Student Text Pages
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525
Table of Contents
The Reference Guide is one of the six volumes of the Teacher’s guides
Scope and Sequence
Scope and Sequence
The way in which concepts are sequenced and presented to the student is critical to the teaching and learning process. The CPO Science Program is based upon inquiry and
discovery teaching approaches. As a result, the Investigations, hands-on activities, are frequently completed before reading the accompanying section in the student text.
Both teaching tools are closely aligned and reinforce the same concepts. The Scope and Sequence Charts identify how the Student Edition and Investigations are aligned
and highlights the learning goals, major science skills and needed equipment/materials taught in the Unit. These charts are a quick reference to what concepts students will
be learning and the sequence and duration for the instruction. A class period is assumed to be 45 minutes.
1.1 Time and Distance
•
•
•
•
Learning Goals
Measure time to 0.0001 seconds using
an electronic timer and photogates.
Understand and work with the concepts
of accuracy, precision, and resolution of
measuring instruments.
Use hours, minutes, and seconds in
calculation.
Measure distances in inches to 1/16th
precision and metric to 0.5 mm
precision.
Key question:
How do we describe and measure the
world?
Leading questions:
• Why are accurate measurements of time
necessary?
• How does the photogate timer work?
• How we measure and communicate length
and position?
Reading Synopsis
People use the word “time” in two ways. Sometimes we ask, “What time is
it?” in order to identify a particular moment. At other times we ask, “How
much time has passed?” In this case, we are measuring the amount of time
between two moments.
Intervals of time are measured in units of seconds, hours, days, years, and
centuries. Sometimes a mixed unit, such as “2 days and 12 hours” is used. In
order to complete calculations with time, the mixed unit must be converted to
a single unit, such as “2.5 days” or “60 hours.”
Distances are measured in English and metric units. The English system uses
feet, inches, and miles while the metric system uses meters, centimeters, and
kilometers (among other units). The reading shows how to use the English
and metric ruler to make measurements.
Sequence: Students complete the reading before the Investigation.
Materials and Setup
• Timer and two photogates (with
9V battery or AC adapter, and cords
for connecting photogates)
• Metric ruler
• English ruler
• Sheet of scrap paper
Duration: One class period
1
Scope and Sequence
1.2 Investigations and Experiments
Learning Goals
• Identify the variables that affect the
speed of a car rolling down a ramp.
• Design an experiment where there are
several variables to be controlled.
• Recognize a poorly designed experiment
where more than one variable has been
changed.
Key question:
How do we ask questions and get answers
from nature?
Leading questions:
• What are the factors that affect the speed
of a car rolling downhill?
• How do we design experiments?
• How do we interpret the results of
experiments?
Reading Synopsis
An experiment is a situation we set up to see what happens. Scientific
evidence comes from the results of experiments and observations. The
scientific method is a process for collecting reliable scientific evidence and
using the evidence to decide among many possible explanations. Experiments
may start with a research question or hypothesis. The hypothesis often
assumes a cause and effect relationship among several variables. “If I do this,
then that will happen.” A good experimental design controls the variables so
the results identify cause and effect relationships without ambiguity.
Experimental techniques are also an important part of a good experiment.
Sequence: Students complete the reading after the Investigation.
Materials and Setup
Car and ramp
Physics stand
1-3 weights
Timer and two photogates (with 9V
battery or AC adapter, and cords for
connecting photogates)
• Ruler or tape measure
• Pencil and paper or lab notebook
•
•
•
•
1.3 Speed
Learning Goals
• Calculate speed in units of inches per
second, feet per second, and centimeters
per second.
• Use photogates to measure speed
• Evaluate the effect of changing different
variables on speed.
Key question:
What is speed and how is it measured?
Leading questions:
• How do we measure speed?
• What things affect the speed of a car
rolling downhill?
2
Reading Synopsis
The reading reviews the definition of speed as the distance traveled divided
by the time taken. Units for speed are summarized in English and metric
systems. The use of the word “per” meaning “for each” or “for every” is
discussed in the context of speed being stated as distance per time, with miles
per hour being a common example. The general approach to solving physics
problems in five steps is outlined.
Materials and Setup
Car and ramp
Physics stand
1-3 weights
Timer and two photogates (with 9V
• At least one calculator
•
•
•
•
Scope and Sequence
2.1 Using a Scientific Model to Predict Speed
Learning Goals
• Construct a speed vs. distance graph.
• Use a graph to make a prediction that
can be quantitatively tested.
• Calculate the percent error between a
measurement and a prediction.
Key question:
Can you predict the speed of the car at any
point on the ramp?
Leading questions:
• How do we measure the speed of the car
at different points on the ramp?
• How can a graph be used to make
predictions?
• How can we determine if our data is
reliable and our experiment is
reproducible?
Reading Synopsis
Models are an important part of science and everyday life. A mental model is
how we estimate our own, and others’, movements. A physical model can be
looked at, touched, and measured. A conceptual model describes a system
and how it works.
A graphic is model one of the most important models used in science. You
can graph speed of the car at different positions on the ramp. The graph shows
the change in speed at different points on the ramp. A graph not only shows
the relationship between variables, but shows how much one variable affects
another. A graph that shows a steady relationship between variables help us
identify relationships that exist in nature and can also be used to predict
unknown values.
Materials and Setup
• Timer and two photogates (with 9V
• Physics Stand
• Car and ramp
• Simple calculator
• Graph paper
• Pencils and ruler or straightedge
Duration: Three class periods
Reading Synopsis
In physics, the word position means where you are compared to where you
started. The position vs. time graph shows where things are at different times.
The graph shows much more detail about motion than would a simple
statement of the average speed.Average speed tells you how far a person
traveled and the total time taken. A graph, on the other hand, shows where the
person was at every minute of the trip.
The speed is equal to the slope of the position vs. time graph. Slope is the
change in y divided by the change in x. Slope can be calculated for all or part
of a curve on the graph. If you determine the slope over a very small change
in time you are finding instantaneous speed.
Materials and Setup
• Tape measure
• Physics stand
• Car and ramp
• Graph paper
2.2 Position and Time
Learning Goals
• Identify the variables that affect the
speed of a car rolling down a ramp.
• Design an experiment where there are
several variables to be controlled.
• Recognize a poorly designed experiment
where more than one variable has been
changed.
Key question:
How do you model the motion of the car?
Leading questions:
• What is the relationship between speed,
distance, and time?
• What does a graph of distance vs. time tell
you about the speed of the car on the
ramp?
• How can we determine speed from a
distance vs. time graph?
• Does the speed of the car change as it
moves down the ramp?
3
Scope and Sequence
2.3 Acceleration
Learning Goals
• Explain the difference between speed
and acceleration.
• Calculate acceleration from a formula.
• Calculate acceleration from the slope of
a speed vs. time graph.
Key question:
How is the speed of the car changing?
Leading questions:
• Is the speed of the car changing as it
moves down the ramp?
• What is acceleration?
• What is the difference between
acceleration and speed?
4
Reading Synopsis
The speed of things is always changing. It is important to be able to describe
and measure changes in speed. A change in speed is called acceleration.
Speeding up and slowing down are examples of acceleration. Acceleration
also refers to changes in velocity. Even if a car’s speed is steady, the car is
accelerating when there is a change in its direction.
In mathematical terms, acceleration is the rate of change of the speed of an
object.
If we coast on a bike down a steep hill, we accelerate. This acceleration is due
to gravity. Any object that is dropped accelerates downwards. The slope of a
speed vs. time graph is equal to the acceleration.
Materials and Setup
• Tape measure
• Physics stand
• Car and ramp
• Graph paper
• Data from Investigation 2.2: Position
and Time
Scope and Sequence
3.1 Force, Mass, and Acceleration
Learning Goals
• Explain that force causes acceleration.
• Use a graph to identify relationships
between variables.
• Explain Newton’s Second Law and the
relationship between force, mass, and
acceleration.
Key question:
What is the relationship between force,
mass, and acceleration?
Leading questions:
• What is a force?
• How does varying the force on the car,
while keeping its mass constant, affect its
acceleration?
• What is the relationship between force,
mass, and acceleration?
Reading Synopsis
Newton’s laws of motion are presented and applied. A force is an action
which has the ability to change motion. The first law states that every object
stays at constant velocity (or at rest) unless acted on by a force. Newton’s
second law describes how the acceleration of an object is related to its mass
and to the force acting on the object.
Inertia is the property of objects to resist acceleration. Inertia is created by
mass. Objects with more mass resist acceleration proportionally greater than
objects with low mass.
In equilibrium, the total of all forces on an object is zero and the first law tells
us the object remains moving at constant speed or at rest. If the total of all
forces on an object is not zero, the forces are unbalanced, and the second law
tells us the object is accelerating.
Materials and Setup
• At least one balance capable of
measuring a mass of 400 grams.
Each group should have:
• Spring scales for measuring force
• Tape measure
• Weights
• Physics stand
• Car and ramp
• Graph paper
Reading Synopsis
Gravity is a force that pulls every mass toward every other mass. Since the
Earth is the biggest mass around, we experience gravity as a force that pulls
everything toward the center of the Earth. We call the force of gravity weight.
Using Newton’s second law, we calculate weight from mass and the
acceleration of objects in free fall.
Friction is a catch-all word for all forces that act against motion. Friction can
come from rubbing, sliding, fluid motion, air motion and other situations. The
force of friction always opposes the motion that produces the friction.
Materials and Setup
• At least one balance capable of
measuring a mass of 400 grams.
• Spring scales for measuring force
• Tape measure
• Weights
• Physics stand
• Car and ramp
• Graph paper
3.2 Weight, Gravity, and Friction
Learning Goals
• Describe the effects of friction
• Explain why in real life, heavier objects
often fall faster than lighter objects, even
though this appears to contradict the
laws of physics.
• Evaluate the percent change in a
variable and correlate this to an
observed effect.
Key question:
How does increasing the mass of the car
affect its acceleration?
Leading questions:
• How is motion affected by friction?
• Do heavier objects fall faster than lighter
objects?
• What is friction?
5
Scope and Sequence
3.3 Equilibrium, Action, and Reaction
Learning Goals
• Identify action/reaction pairs and the
objects they act on.
• Apply the third law to any situation that
involves force.
• Demonstrate equilibrium situations with
objects at rest or moving with constant
speed.
Key question:
What is Newton’s third law of motion?
Leading questions:
• What do we mean by action and reaction?
• Why don’t equal and opposite forces
cancel each other out?
• What does Newton’s third law mean to
every day experiences?
• What is equilibrium and how does it relate
to forces?
6
Reading Synopsis
Newton’s third law of motion explains why. This law describes the interaction
between objects that occur because forces come in pairs. Newton’s third law
states that for every force (action) there is an equal and opposite force
(reaction).
Momentum is the product of mass times velocity. The law of conservation of
momentum arises from action/reaction forces. When you throw a ball from a
skateboard, it carries away momentum in one direction. You move backwards
carrying an equal and opposite amount of momentum in the other direction.
Materials and Setup
• Timer and two photogates (with
9V battery or AC adapter, and cords
for connecting photogates)
• Tape measure
• String, about 1 meter long
• Physics stand
• Car and ramp
• Weights
Scope and Sequence
4.1 Forces and Machines
Learning Goals
• Define mechanical systems, machines,
simple machines, input force, and output
force.
• Identify input and output forces on a
simple machine.
• Measure input and output forces on a
block and tackle machine.
Key question:
How do simple machines work?
Leading question:
• What is a mechanical system?
• How does a machine work?
• What happens to forces in a machine?
• How do you measure input and output
forces in a machine?
Reading Synopsis
A machine is a device with moving parts that work together to accomplish a
task. Using a machine requires an input of force so that an output of force is
generated to do the task.
Many complex machines combine simple machines with a power source (like
an engine). A simple machine is unpowered. Examples include levers, the
wheel and axle, the block and tackle (rope and pulley), gears, and ramps.
Machines are useful because they create mechanical advantage. Mechanical
advantage is the ratio of output force to input force. A force is an action that
has the ability to change motion. The units for force are the newton and the
pound. There are 4.48 newtons in one pound.
The people who design machines are called engineers. Engineers use
scientific knowledge to create or improve inventions that solve problems
using a process called the design cycle.
Materials and Setup
Ropes and Pulleys set
Physics Stand
Force scale
Weights
Reading Synopsis
Each day simple machines are used to perform tasks. The lever is one simple
machine that is especially useful for multiplying the force than can be applied
to an object and for changing the direction of objects.
Levers pivot on a point called the fulcrum. Relative to the fulcrum, input
force is applied to achieve output force. The placement of the fulcrum, input
force and output force is important for doing certain kinds of tasks.
A pair of pliers is an example of a first class lever. The input and output
forces are balanced on either side of the fulcrum. A wheelbarrow is an
example of a second class lever. The output force (anything in the
wheelbarrow) is between the input force and the fulcrum (the wheel) in a
second class lever. Arms and legs are third class levers. The input force
(muscle strength) is between the fulcrum and the output force.
Mechanical advantage is the ratio of the length of the input arm over the
length of the output arm.
Materials and Setup
Levers set
Physics Stand
Weights
String loops
•
•
•
•
4.2 The Lever
Learning Goals
• Describe how a lever works.
• Identify the relationship between force
and distance on a lever.
• Apply the concept of mechanical
advantage to levers.
Key question:
How does a lever work?
Leading questions:
• What is a lever?
• What is the relationship between force
and distance in a simple machine?
• What factors balance a lever?
•
•
•
•
7
Scope and Sequence
4.3 Designing Gear Machines
Learning Goals
• Build gear machines and deduce the rule
for calculating the number of turns for
each gear in a pair of gears.
• Apply ratios to design machines with
gears.
• Design a gear machine to solve a
specific problem.
Key question:
How do gears work?
Leading questions:
• What is the law of gearing?
• How can gear ratios be used to design
machines?
8
Reading Synopsis
Many machines, like bicycles, clocks, and cars, have rotating parts like
wheels. To make these machines work, some parts must turn faster than
others. Gears are one of the best ways to make machines where some parts
turn at different speeds than other parts.
When two or more gears work together in a machine, there is an input gear to
which input force is applied, and an output gear to which output force is
applied. Gears have teeth so that force and motion can be transferred from
one gear to another without slippage.
The amount of motion achieved with a set of gears is described using a gear
ratio. The gear ratio tells you how many times one gear turns relative to a
connected gear. The ratio is determined by the numbers of teeth on the gears.
The ratio of teeth for a pair of gears is inverse to the ratio of the turns. This is
called the law of gearing. For example, if a small gear with 12 teeth is
connected to a larger gear with 36 teeth, the small gear will turn 3 times for
every one time that the larger gear turns.
Materials and Setup
• A physics stand
• A set of gears including one each of a
12-tooth, 24-tooth, and a 36-tooth
• A simple calculator
Scope and Sequence
5.1 Work
Learning Goals
• Calculate the amount of work done by a
simple machine.
• Use units of joules to measure the
amount of work done.
• Analyze the effects of changing force or
distance in a simple machine.
Key question:
What happens when you multiply forces in
a machine?
Leading questions:
• What is work?
• How is the amount of work measured?
• How are force and distance related in
machines?
Reading Synopsis
The work done to an object is equal to the force applied times the distance the
force is applied. When you push a box with a force of one newton a distance
of one meter, you have accomplished one joule of work. One joule is equal to
one newton-meter.
The amount of work input for a machine must always be equal to or greater
than the work output. The work output of a simple machine never exceeds the
work input. In order to produce a large output force with a small input force,
the input force is applied over a long distance. In a block and tackle system,
you increase input distance by adding more supporting strands.
Efficiency is the ratio of work output to work input. For real machines, work
output is always less than work input because some work is always lost due to
frictional forces. The rate at which work is done is called power. Power is
work (in joules) divided by time (in seconds). The unit for power is the watt.
One watt is equal to one joule/second.
Materials and Setup
Ropes and Pulleys set
Physics Stand
Force scale
Ruler or meter stick
Weights
Duration: Two class periods
Reading Synopsis
Energy has many forms (motion or heat) and it can travel in different ways (as
light, sound, or electricity). The workings of the universe depend on flowing
energy.
Energy is the ability to do work. This means that any object with energy can
create a force that is capable of acting over a distance. Like work, energy is
measured in joules. This is because energy is really stored work. Two (of
many) kinds of energy are potential and kinetic energy. Potential energy is
related to the position of an object relative to the surface of the Earth. The
formula for potential energy is the mass of an object times the acceleration of
gravity times height of the object. Kinetic energy is energy of motion. The
formula for kinetic energy is 1/2 times mass of the object times its speed
squared.
The law of conservation of energy states that energy cannot be created or
destroyed as it flows from place to place or is transformed.
Materials and Setup
Roller coaster
Timer and one photogate
Physics Stand
A steel marble (for the Investigation)
A black marble (for the Extended
Activity)
• Pencils, rulers, and simple calculators
•
•
•
•
•
5.2 Energy Conservation
Learning Goals
• Identify the relationship between speed
and height on a roller coaster.
• Describe the motion of the marble on the
Rollercoaster in terms of energy and the
law of conservation of energy.
• Discuss the energy transformations that
occur in a given situation.
Key question:
What is energy and how does it behave?
Leading questions:
• How are speed and height related on a
roller coaster?
• What is energy?
• How are energy and motion related?
• How is energy conserved on a roller
coaster?
•
•
•
•
•
9
Scope and Sequence
5.3 Energy Transformations
Learning Goals
• Identify and describe different types of
energy.
• Distinguish between potential and
kinetic energy.
• Discuss the energy transformations that
occur in a real-life situation.
Key question:
Where did the energy go?
Leading questions:
• What are the different types of energy?
• How is energy conserved in different
situations?
• Where does the energy go in a system?
10
Reading Synopsis
Energy takes many forms. These include mechanical, radiant, electrical,
chemical, and nuclear energy. Kinetic and potential energy are types of
mechanical energy. Radiant (or light) energy is also known as
electromagnetic energy. Examples include visible and ultraviolet light and
heat. Electrical energy is our source of energy for lighting and appliances.
Chemical energy is stored in molecules. We eat food or burn fossil fuels to
obtain chemical energy. Nuclear energy results when the nuclei of atoms are
combined or split.
Energy transformations are events in which energy is converted from one
form to another. Energy is like nature’s money. Energy can be spent, saved
and exchanged. You can use energy to “buy” speed, height, temperature, and
mass. You have to have some energy to start.What you spend diminishes what
you have left.
Materials and Setup
• the Student Book
• A piece of large paper or newsprint
and colored markers
Scope and Sequence
6.1 What is a Circuit?
Learning Goals
• Build simple circuits.
• Trace circuit paths.
• Read and use the electric symbols for
battery, bulb, wire, and switch.
• Draw a circuit diagram of a real circuit.
• Explain why electrical symbols and
circuit diagrams are used.
• Explain how a switch works.
• Identify open and closed circuits.
Key question:
What is an electric circuit?
Leading questions:
• What is found inside light bulbs, TVs,
stereos, toasters, and other electrical
devices?
• What is an electric circuit?
• How are electric circuits constructed?
Reading Synopsis
Electricity usually means the flow of something called electric current in
wires, motors, light bulbs, and other devices. Electricity flows through
structures called electric circuits.
Because a complete path is needed for electricity to work, circuits are
controlled by switches, which either break or connect the circuit path. When a
switch is on, the circuit path is complete, or closed. When a switch is off, the
circuit path is broken, or open.
When people build and design circuits, they record their work with drawings
called circuit diagrams. In a circuit diagram each electrical part is shown by
standard symbol, called an electrical symbol.
Materials and Setup
• Electric circuits kit
Reading Synopsis
The widespread use of electricity only became possible after people began to
understand its cause. All electrical events occur because all mass has the
property of electric charge. Charge comes in two kinds: positive charge and
negative charge.
Charge is part of the structure of atoms. Each proton of an atom carries
positive charge and each electron of an atom carries negative charge. Most
objects have an equal amount of positive and negative charge, and are
therefore called neutral. If an object gains excess negative or positive charge,
it is said to be charged.
Two charged objects affect each other. Unlike charges attract each other and
like charges repel each other. These forces are called electrostatic forces.
The use of muscles, the strength of a solid table, the nature of water, and
friction, are some things that exist because of electrostatic forces.
Electrostatic forces are much stronger than the force due to gravity.
Materials and Setup
• 2 rectangles of clay, about 2 cm by 2
cm by 4 cm
• 4 flexible straws
• Ruler
• ScotchTM brand magic tape
• Small light objects such as pieces of
thread and small pieces of paper
(optional)
• Pairs of materials that can be charged,
such as plastic combs rubbed with
wool, glass rubbed with wool, and dry
wood rubbed with glass (optional)
• An electroscope (shown above)
6.2 Charge
Learning Goals
• Charge pieces of tape and observe their
interactions with an electroscope.
• Identify electric charge as the property
of matter responsible for electricity.
• List the two forms of electric charge.
• Describe the forces electric charges
exert on each other.
Key question:
What is moving through a circuit?
Leading questions:
• What causes electricity?
• How did people study electricity in the
past?
• What is moving through the wires of a
circuit?
11
Scope and Sequence
7.1 Voltage
Learning Goals
Explain voltage.
Measure volts with an electrical meter.
Describe the role of a battery in a circuit.
Calculate the total voltage of several
batteries in series.
• Describe the transfer of energy in a
circuit.
Key question:
Why do charges move through a circuit?
Leading questions:
• What does a battery do?
• Why do charges move through a circuit?
•
•
•
•
Reading Synopsis
A battery uses chemical energy to separate and store positive and negative
charges. Because work is done to separate the charges, the work is stored as
potential energy. The amount of potential energy of each unit of charge is
called voltage. Like height, which is related to gravitational potential energy,
voltage is measured from one point to another. We usually assign the negative
terminal of a battery to be 0 V. This makes the voltage of every other place in
the circuit relative to the negative end of the battery.
In a circuit, charges transfer their energy. If you measure voltage at different
points in the circuit you will see this voltage drop. Voltage drops are large for
anything that uses energy (motors, bulbs, resistors). The voltage drop along a
wire is very small.
Voltage is measured in units called volts, which is equal to one joule of
energy per coulomb of charge.
Materials and Setup
• Electrical meter
• Battery
Reading Synopsis
Current is the flow of electric charges. You can think of electrical current
much as you would think of a current of water. Current tells you how many
charges have moved past a point during a period of time.
The charges that make up current come from the materials of a circuit.
Charges exist in all materials and can move once there is a difference in
voltage across the material.
Current is measured in units of amperes, called amps for short. One ampere is
a flow of one coulomb of charge per second. A current of 10 amperes in a
circuit means that 10 coulombs of charge flow through any point in the circuit
every second.
Batteries create a current that flows steadily in one direction through a wire.
This kind of current is called direct current. The electricity in your house uses
current that reverses in direction rapidly. This kind of current is called
alternating current.
Materials and Setup
• A battery and bulb circuit
7.2 Current
Learning Goals
• Explain current.
• Measure amps with an electrical meter.
Key question:
How do charges move through a circuit?
Leading questions:
• How do charges move through a circuit?
• How is the flow of charge measured?
12
Scope and Sequence
7.3 Resistance
Learning Goals
• Measure ohms with an electrical meter.
• List the three major classifications of
materials in terms of ability to carry
current and know at least one example of
each.
• Explain electrical conductivity and
resistance.
• Compare electrical conductivity and
resistance.
Key question:
How well does current travel through
different materials and objects?
Leading questions:
• Why do electrical devices usually contain
metal parts?
• Why are electrical devices often encased
in plastic or glass?
Reading Synopsis
If you apply voltage across a material, charge flows and you can measure a
current. In different materials, the amount of current varies. This property of a
material is called its electrical conductivity. The ability of materials to carry
current is classified in three categories. Conductors are materials that easily
carry current, insulators are materials that mainly block current, and
semiconductors are materials that are in-between. You can compare the
electrical conductivities of materials by measuring current flow through test
objects of identical size.The resistance of an object describes how easily
charges flow through it, in comparison to any other object. High resistance
means it is difficult for current to flow. Low resistance means it is easy for
current to flow. Devices that use electrical energy have resistance. The more
energy a device uses, the more resistance it has. Resistance is measured in
units of ohms.
Materials and Setup
• Objects to measure for resistance:
light bulb, steel paper clip, quarter,
dime, penny, plastic item, air, and
pencil lead; can include additional
optional materials such as glass,
different kinds of metal, a shiny
nonmetallic material such as Mylar,
water, dry salt, wet salt, etc.
• Ruler
• 4.5 meters of aluminum wire, 28
gauge
• 4.5 meters of copper wire, 28 gauge
• A bulb
Duration: One to two class periods
13
Scope and Sequence
8.1 Ohm’s Law
Learning Goals
• Describe how current changes when
resistance is increased.
• Describe how current changes when
voltage is increased.
• Describe how voltage, current, and
resistance are related.
• Explain why resistors are used in a
circuit.
Key question:
How are voltage, current, and resistance
related?
Leading questions:
• How do you know how much current will
flow or how much voltage or resistance
you will need in a particular circuit?
Reading Synopsis
German physicist Georg Ohm (1787-1854) experimented with circuits to find
a mathematical relationship present in most circuits. The relationship that he
discovered, I = V/R, is called Ohm’s law. When voltage is increased, current
also increases. When resistance is increased, current decreases.
Even if a material obeys Ohm’s law, its resistance can change when it is
cooler or warmer. At higher temperatures, the atoms move around more and
collide more often with moving charges. Therefore, resistance increases with
temperature. Hot metal has more resistance than cold metal.
Most circuits have preset voltage sources. Current can only be varied by
changing the resistance in the circuit. Components called resistors are used.
Resistors are made of materials that keep the same resistance over a wide
range of temperatures and currents.
Materials and Setup
Electric circuits kit
Electrical meter
Graph paper
Ruler or straightedge
Reading Synopsis
Appliances often have a label that lists the number of watts or kilowatts. The
watt (W) is a unit of power. Power measures the rate of energy transfer. One
joule per second is equal to one watt. A 100 watt light bulb uses 100 joules of
energy every second.
You can calculate power in a circuit using the electrical quantities you have
already learned how to measure. Watts equal joules/second, so you can
calculate electrical power in a circuit by multiplying voltage times current. If
these two quantities are multiplied together, you will find that the units of
coulombs cancel out, leaving the equation for power.
Utility companies charge for a unit called the kilowatt-hour. One kilowatthour means that a kilowatt of power has been used for one hour. If you know
the cost per kilowatt-hour, you can estimate the cost of running an appliance
for a period of time.
Materials and Setup
• The teacher should provide two or
three small appliances such as an
iron, toaster oven, electric drill, desk
lamp, or hair dryer. Students will
learn how to find the power rating
stamped on each appliance.
• Calculators
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8.2 Work, Energy, and Power
Learning Goals
• Explain power.
• Calculate power use in a circuit.
• Rank the amount of power used by
various household appliances.
• Estimate the cost per month of using a
common household appliance.
• Use dimensional analysis to find out
what we buy from electric utility
companies.
Key question:
How much does it cost to use the electrical
appliances in your home?
Leading questions:
• How can electricity do work?
• What do we mean when we say that
household appliances use electricity?
• What do the terms on an electric bill
mean?
• Which household appliances are the
costliest to operate?
14
Scope and Sequence
9.1 More Electric Circuits
Learning Goals
• Describe and identify a series circuit.
• Describe and identify a parallel circuit.
Key question:
What kinds of electric circuits can you
build?
Leading questions:
• How many different fundamental ways
can you configure circuits?
• What do you observe in different kinds of
circuits?
• How are our houses wired?
Reading Synopsis
There are two basic ways to put circuits together. In a series circuit the current
can only take one path. All the current flows through every part of the circuit.
All the circuits you have studied so far have been series circuits. In a parallel
circuit, the current can take more than one path. Parallel circuits have at least
one branch where the current can be split.
The electrical circuits in homes and buildings are wired in parallel circuits.
Parallel circuits have several advantages. Each outlet has its own current path
and therefore can be turned on and off independently of other outlets. Each
outlet sees the same voltage because one side of each outlet is connected to
the same wire.
Materials and Setup
Reading Synopsis
In a series circuit, all current flows through a single path. When the circuit has
more than one component, the resistance of each component adds together.
Because each component has resistance, part of the energy of the charges is
transferred to each components. The law of conservation of energy helps us to
understand what is happening. The energy provided by the battery is split
among all the components in the circuit.
We can measure exactly how voltage is distributed among each component by
measuring the voltage across it. This is called the voltage drop. In a series
circuit, all the voltage drops must add up to the voltage of the battery. This
relationship is known as Kirchhoff’s voltage law.
Materials and Setup
• Calculator
• Graph paper
Duration: Two to three class periods
9.2 Series Circuits
Learning Goals
• Calculate total resistance in series
circuits.
• Build circuits with fixed and variable
resistors.
• Analyze series circuits using Ohm’s law.
• Use Kirchhoff’s voltage law to find the
voltage drop across a circuit component.
Key question:
How do you use Ohm’s law in series
circuits?
Leading questions:
• How do you use Ohm's law in complex
series circuits?
15
Scope and Sequence
9.3 Parallel Circuits
Learning Goals
• Build circuits with fixed and variable
resistors.
• Compare current flow in series and
parallel circuits.
• Compare voltage in series and parallel
circuits.
• Use Kirchhoff’s current law to find an
unknown current.
• Identify a short circuit.
• Explain why a short circuit is dangerous.
Key question:
How do parallel circuits work?
Leading questions:
• How do you use Ohm's law in a parallel
circuit?
• What is a short circuit?
16
Reading Synopsis
A parallel circuit has at least one branch in the circuit which creates different
paths for current to flow. In a parallel circuit the voltage is the same across
each branch because all the branch points are on the same wire. The current in
each branch will depend on how much resistance is in the branch. When you
plug a desk lamp and a power saw into an outlet, they each use very different
amounts of current.
The total current in a parallel circuit is equal to the sum of all the branch
currents. This rule is known as Kirchhoff’s current law.
With a parallel circuit, the branch with the lowest resistance draws the most
current. A short circuit is a branch with zero or very low resistance. You can
create a short circuit by connecting a wire directly between two ends of a
battery. Short circuits are dangerous because huge amounts of current flow
through them, making a wire dangerously hot. Circuit breakers and fuses
open a circuit if a short circuit occurs.
Materials and Setup
Electrical meter
Pencil and paper or lab notebook
Calculator
A test set of three batteries that has a
combined voltage of about 3.6 volts
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Scope and Sequence
10.1 Permanent Magnets
Learning Goals
• Describe the properties of a permanent
magnet.
• Describe and measure the forces that
magnets exert on other magnets.
• Describe the magnetic field.
Key question:
What effects do magnets have?
Leading questions:
• What effects do magnets have, both on
each other and on other materials?
• What is magnetic force and how can you
measure it?
• What is the magnetic field?
Reading Synopsis
Magnetic means the ability to make forces on magnets or other magnetic
materials. A permanent magnet is a material that keeps its magnetic
properties, even when it is not close to other magnets.
All magnets have the following common properties:
• Magnets always have two opposite “poles,” called north and south.
• If divided, each part of a magnet has both north and south poles; we never see
an unpaired north or south pole.
• When near each other, magnets exert magnetic forces on each other.
• The forces between magnets depend on pole alignment; two unlike poles will
attract each other and two like poles will repel each other.
The model of a magnetic field was developed to describe how a magnet
exerts magnetic force.
Materials and Setup
• 2 ceramic magnets
• Materials to test: plastic spoon, a
wooden pencil, a steel paper clip, an
alligator clip, aluminum foil, a nickel,
a penny, a brass key, a nail, chalk,
skin, and clothing snaps; if available,
shiny nonmetallic items such as a
Mylar balloon or a piece of metallic
gift wrap
• Overhead transparency of the picture
of the magnetic field
• Several ounces of iron filings
• Clear plastic tray OR clear plastic
bottle
• Ceramic magnet
• String
• Compass
Reading Synopsis
In 1819, Hans Christian Øersted, the Danish physicist and chemist (17771851), noticed that a current in a wire caused a compass needle to deflect.
With his discovery, Øersted was the first to identify the principle of an
electromagnet. Electromagnets are magnets that are created when there is
electric current through a wire. The simplest electromagnet uses a coil of
wire, often wrapped around a core of iron.
The magnetic force exerted by a simple electromagnet depends on three
factors:
• The amount of electric current in the wire
• The amount of iron or steel in the electromagnet’s core
• The number of turns in the coil
Why do permanent magnets and electromagnets act the same way?
Electromagnets helped scientists to determine why magnetism exists. Electric
current through loops of wire creates an electromagnet. Atomic-scale electric
currents create a permanent magnet.
Materials and Setup
2 ceramic magnets
3 meters of magnetic wire, 24 gauge
Sandpaper
2 galvanized nails 7 cm in length
Electrical meter
Magnetic materials
100 paper clip
Graph paper
Ruler or straightedge
1 working electromagnet
10.2 Electromagnets
Learning Goals
• Build an electromagnet.
• Analyze how electric current affects the
strength of the magnetic field in an
electromagnet.
• Compare permanent magnets and
electromagnets.
Key question:
Can electric current create a magnet?
Leading questions:
• What is an electromagnet?
• What is the relationship between current
and magnetic force in an electromagnet?
• Why do magnets and electromagnets act
the same way?
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17
Scope and Sequence
10.3 Electric Motors and Generators
Learning Goals
• Build a working electric motor and
measure its speed
• Demonstrate how electromagnets and
permanent magnets interact to make an
electric motor work
• Design different motors and evaluate
them for speed and electric power
• Build and test several electric generators
designs
• Explain the relationship between the
amount of electricity generated and the
speed and design of the generator
Key question:
How does an electric motor or generator
work?
Leading questions:
• How does an electric motor work?
• How can you design a motor for optimum
performance?
• How much electric power does a motor
use?
• How does an electric generator work?
• How much electricity can a generator
produce?
18
Reading Synopsis
Electric motors use attracting and repelling magnets to spin a rotating spindle
called the armature. Both permanent magnets and electromagnets are used.
Electromagnets are necessary because they can be switched from North to
South by reversing the current in a coil of wire. The commutator is a part of
the of the motor that switches the electromagnets from attract to repel at the
right time to keep the armature spinning.
Moving electric current creates magnetism. The opposite process is also
possible. A moving magnet can cause electric current to flow in a coil of wire.
Using moving magnets to create electric current is called electromagnetic
induction and is the principle behind the electric generator. In a power plant, a
rotating turbine spins magnets past coils of wire to create electricity. The
energy to spin the turbine comes from burning fossil fuels, nuclear reaction,
or even solar power. Because the magnetism switches back and forth,
generators produce attenuating current (AC) electricity. This is one reason
your house and school use AC electricity.
Materials and Setup
• one electric motor kit with batteries
• one timer, wires, and one photogate
• one electric meter
Duration: Three to four class periods
Scope and Sequence
11.1 Introduction to Harmonic Motion
Learning Goals
• Measure the amplitude and period of a
pendulum
• Predict how the period of a pendulum
will change using knowledge of physical
parameters such as mass, amplitude, and
length.
• Design and build a clock to tell 30
seconds.
• Observe and describe damping and how
it effects oscillators.
Key question:
How do we describe the back and forth
motion of a pendulum?
Leading questions:
• What is harmonic motion?
• Why is harmonic motion important to
understand?
• Are there quantities (like speed and
acceleration) that we can measure and use
to describe harmonic motion?
Reading Synopsis
Harmonic motion is motion that repeats in cycles. An oscillator is a system
that shows harmonic motion. Oscillators are found in nature (Solar System),
Art (musical instruments) and technology (clocks, cell phones). The period is
the time to complete one cycle. Frequency is “how often” which technically
the number of cycles per unit of time. One hertz is a frequency of one cycle
per second. Frequency and period are relate, frequency is the inverse of
period, and vice-versa.
Amplitude is the size of the cycle. When oscillators slow down due to friction
the process is called damping. The amplitude of a damped oscillator gradually
decays to zero.
Materials and Setup
Physics stand
Pendulum
Tape measure or meter stick
Electronic timer with one photogate,
AC adapter, and cord
• Pencils, rulers, and simple calculators
• Access to at least one gram balance
for measuring the mass of the
pendulum.
Reading Synopsis
Harmonic motion graphs show cycles. The most common graph shows
position versus time. Positive and negative positions are used to distinguish
motion on either side of equilibrium. The amplitude is the peak-to-peak
distance on a the graph., The period is read from the x-axis as the time for one
cycle.
It is useful to compare harmonic motion with circular motion. One rotation of
a circle corresponds to one complete cycle. We often use degrees to indicate
where a motion is in its cycle. 90 degrees is 1/4 of a circle so it represents 1/4
cycle. Phase describes where the motion is compared to a full cycle. Half-way
through a cycle would be a phase of 180 degrees. Two harmonic motions are
in-phase when the phase difference between them is zero and out-of-phase
when the phase difference between them is not zero. Motions that are 180
degrees out of phase are always on opposite ends of their cycles.
Materials and Setup
• Pencils, rulers, and a simple
calculator
Duration: one class period
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11.2 Graphs of Harmonic Motion
Learning Goals
• Construct graphs of harmonic motion
• Interpret graphs of harmonic motion to
determine phase, amplitude, and period
• Use the concept of phase to describe the
relationship between two examples of
harmonic motion.
Key question:
How do we make graphs of harmonic
motion?
Leading questions:
• What does harmonic motion look like on
a graph?
• How do you read a graph of harmonic
motion?
• Position tells us where we are in normal
(linear) motion. How do we tell where we
are within the cycle of harmonic motion?
19
Scope and Sequence
11.3 Simple Mechanical Oscillators
Learning Goals
• Explain the cause of harmonic motion
using the concepts of restoring force and
inertia.
• Explain and apply the concepts of stable
and unstable equilibrium
• Construct an oscillator from common
materials.
• Describe and test ways to change the
period of an oscillator.
Key question:
What kinds of systems oscillate?
Leading questions:
• How do you make an oscillator?
• Why does harmonic motion happen?
• Can we predict if a system will oscillate?
• How can you change the motion of an
oscillator?
20
Reading Synopsis
This is a very short (1 page) reading. A pendulum is one mechanical
oscillator. A mass hanging from a spring is another. The spring provides the
restoring force. A vibrating string (or rubber band) is another simple
oscillator.
Sequence: Students complete the reading before the Investigation. There is also
substantial new material to read in the investigation itself.
Materials and Setup
• Pencils, rulers, and a simple
calculator
• rubber bands
• thin, flexible plastic rulers
• elastic string
• springs
• stiff wire, such as from a coat hanger
• modeling clay
• weights
• marbles or small balls
• scissors
• hot melt glue and glue gun
• string
• cardboard
Duration: Two class periods or longer
if more elaborate projects are created.
Scope and Sequence
12.1 Waves
Learning Goals
• Model transverse and longitudinal
waves and their characteristics with a
stretched string.
• Explain the role waves play in our daily
lives, including our effort to
communicate.
Key question:
How do we make and describe waves?
Leading questions:
• What is a wave?
• How are oscillations and waves related?
• How do waves travel?
• Why are waves important?
Reading Synopsis
Waves are a type of oscillation that travels from one place to another. Waves
can be created in ordinary materials like water, strings and springs. Sound is a
wave that is created by the oscillation of air. Light, radio, microwaves, and Xrays are also waves.
We use waves to carry information and energy over great distances. Waves
spread through continuous objects, like a string or a body of water. A
transverse wave has oscillations that are perpendicular to the direction that
the wave travels. Ocean waves are transverse waves. A longitudinal wave has
oscillations that are in the same direction that the wave travels.
Waves have cycles, frequency, amplitude, like all oscillations. Because waves
are spread out and because they travel, waves also have new properties of
wavelength and speed. Wavelength is the length of one complete cycle of a
wave.
Materials and Setup
• 5-N spring scale
• 3 meters of elastic cord
• Tape strong enough to attach the
elastic cord to a desk or table
• Timer and two photogates
• Meter stick or tape measure
Optional activity
• Slinky and snaky springs are great if
you have them. A slinky spring is fat
and short. A snaky spring is thinner
and much longer. If you only have
one or two springs, you can do a
demonstration with them.
Demonstrate longitudinal and
transverse wave pulses as described
in the text.
21
Scope and Sequence
12.2 Waves in Motion
Learning Goals
• Explain the types and shapes of waves.
• Describe diffraction of waves.
• Describe reflection of waves.
Key question:
How do waves move and interact with
things?
Leading questions:
• What shapes do waves come in?
• What happens when a wave hits
something?
22
Reading Synopsis
A wave can be thought of as a series of high points, called crests, and low
points, called troughs. People often use the crest of a wave as a reference
points, called a wave front.
The shape of a wave is determined by the shape of the wave fronts. Two
common shapes are plane waves, which have crests that move froward in
straight lines, and circular waves, which have crests that move outward in
circles. Waves can do different things when they hit an obstacle. The wave
can bounce off the obstacle and move in a new direction, which is called
reflection. The wave can pass into and through the obstacle, which is called
refraction. The wave can bend around or go through holes in the obstacle,
which is called diffraction. The wave can be absorbed by the obstacle and
disappear, which is called absorption.
Boundaries are areas where conditions change. Reflection, refraction, and
diffraction usually occur when a wave crosses a boundary.
Materials and Setup
• Flat tray that can be used for making
water waves. A cookie tray or baking
pan that is 12 x 18 inches works well.
• Container for transferring water,
• Ruler or other straight edge that can
be used to make waves inside the tray
• 2 blocks of wood or plastic that block
the width of the tray
• A supply of water colored with food
coloring. One 1oz bottle of food color
will work for about one gallon of
water. One gallon will fill 5-6 wave
trays. Blue and green are good colors
to work with.
• A spring toy to demonstrate
transverse and longitudinal waves.
The spring toy can be plastic or metal.
Scope and Sequence
12.3 Natural Frequency and Resonance
Learning Goals
• Describe how frequency, wavelength,
and speed are related.
• Recognize and apply the concept of
resonance to any system that can
vibrate.
• Measure the wavelength and frequency
for a vibrating string.
• Recognize and apply the concept of
harmonics in resonant systems.
• Define and apply the concept of natural
frequency.
• Describe and apply methods for
changing the natural frequency of a
system.
• Describe how natural frequency and
resonance are involved in musical
instruments.
Key question:
What is resonance and why is it important?
Leading questions:
• How do we make and control waves?
• What is resonance?
• Is there a relationship between the wave
properties of frequency, wavelength and
speed?
• What is the relationship between waves
and energy?
Reading Synopsis
Just as the length of a string sets the period of the pendulum, the boundaries
and properties of all oscillators favor special frequencies.
To keep a string or any system oscillating, we apply an oscillating force.
When swinging a jump rope, its response is greater when your swinging force
matches the natural frequency of the rope. The matching of force and
response is called resonance.
A guitar string or piano string is an example of a standing wave. The natural
frequency of a vibrating string is called the fundamental. Strings can also
vibrate at frequencies that are multiples of the fundamental. These multiples
are called harmonics.
When two waves meet they can interfere. Constructive interference is when
the waves add to make a larger wave. Destructive interference is when the
waves add to make a smaller wave.
Materials and Setup
Sound and waves generator
Timer
Meter stick or tape measure
Simple calculator
Graph paper
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23
Scope and Sequence
13.1 Sound
Learning Goals
• Identify the range of human perception
of sound.
• Identify the qualities of a good
experiment.
• Design double blind experiments and
explain their importance in discovering
scientific information free from bias.
• Apply a simple binary decision tree to
evaluate the chances of guessing your
way through a multiple question test.
Key question:
What is sound and how do we hear it?
Leading questions:
• What is the range of human perception of
sound?
• How can an experimenter study range of
human perception of sound with a group
of people and be sure that his or her data
is correct?
• What are the qualities of a good
experiment?
• How can we design an experiment and be
confident people are not just guessing the
right answers?
24
Reading Synopsis
Sound is a wave. Sound has wavelength and frequency which is heard as high
or low pitch. The speed of sound is frequency multiplied by wavelength.
The cochlea, in the inner ear, is a spiral, fluid-filled hearing organ. The
perception of sound starts when the eardrum, toward the outer ear, vibrates in
response to sound waves in the ear canal. These vibrations are then
transmitted to the fluid in the cochlea. The nerves at the beginning of the
spiral (the larger end) respond to longer wavelengths with low frequency. The
nerves at the narrower end of the spiral respond to shorter wavelengths with
higher frequency. The range of human hearing is 20 to 20,000 hertz.
Ultrasound is high frequency sound beyond the range of human hearing. It is
used for creating images for medical purposes.
Materials and Setup
A CPO timer
A CPO sound generator and speakers
Graph paper
Simple calculator
Scratch paper sheets for each student
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Scope and Sequence
13.2 Properties of Sound
Learning Goals
• Listen to beats and show how the
presence of beats is evidence that sound
is a wave.
• Create interference of sound waves and
explain how the interference is evidence
for the wave nature of sound.
Key question:
Does sound behave like other waves?
Leading questions:
• What are the properties of sound?
• How do beats prove that sound is a wave?
• Can sounds interfere with each other?
Reading Synopsis
Sound is created by a combination of the inertia of air molecules and the
restoring force of air pressure. Restoring force means that increasing air
pressure in one place results in air molecules spreading out to lower that
pressure. Sound is a longitudinal wave that oscillates between high and low
pressure regions of air (harmonic motion). Anything that vibrates in air
creates a sound wave. Loudness is measured on a logarithmic scale with the
decibel (dB) as the unit. The amplitude of a sound wave (related to loudness)
is one half of the difference between the highest and the lowest pressures in
the wave. A single frequency of sound is heard as a single pitch. Sound
resonates with objects of lengths that match the wavelength of that sound.
Sound travels 340 meters/second under ordinary conditions, but can be
affected by pressure and temperature. The reflection of sound can cause
reverberation (multiple echoes) or interference (due to sound waves
cancelling each other).
Materials and Setup
• One CPO timer
• CPO sound generator
• speakers.
Reading Synopsis
Music is a combination of sound and rhythm. The pitch of a sound is how
high or low we hear its frequency. Rhythm is a regular time pattern in sound
made with either sound and silence, or with different pitches. Most music is
made from a set of frequencies called a musical scale. Harmony is how
sounds work together to create effects and is based on the frequency
relationships of the musical scale. When two frequencies of sound are close,
but not the same, the loudness of the sound seems to oscillate or beat. A good
combination of sounds is called consonance. A bad or unsettling combination
of sounds is called dissonance. A fundamental note of music has a single
frequency and pitch. However, the same note on different instruments sounds
different because instruments produce harmonics. Harmonics are multiples of
the fundamental that we hear along with the fundamental note on a
instrument.
Materials and Setup
• A CPO timer
• A CPO sound and waves set with the
speakers
• Enough plastic straws for each group
member
• two pairs of scissors
It makes the class much more fun if
some students (or teachers) can bring in
musical instruments of different sorts.
Demonstrating how to make the notes
on different instruments illustrates how
the ideas of the unit apply to a wide
range of designs.
13.3 Music
Learning Goals
• Make musical notes by choosing
frequencies of sound.
• Make a simple instrument.
• Explain the foundations of musical
harmony.
Key question:
What is music and how do we make music?
Leading questions:
• What is a musical scale?
• What is a musical note?
• How is sound created and controlled with
a musical instrument?
25
Scope and Sequence
14.1 Introduction to Light
Learning Goals
• Create light using photoluminescence.
• Describe the atomic origin of light.
• Describe the diffraction spectra of
several kinds of lights.
Key question:
How can you make light and how can you
study it?
Leading questions:
• What is light?
• What makes light?
26
Reading Synopsis
Light is a kind of wave we can see with our eyes. These waves are called
electromagnetic (em) waves. We can only see some frequencies of (em)
waves. X-rays, microwaves, infrared light, and ultraviolet light, are examples
of em waves which we cannot see. The energy that creates (em) waves comes
from the electrons in atoms. Electrons exist in energy levels in the atom. An
electron can absorb energy and move from a lower energy level to a higher
energy level. When the electron falls back into the lower energy level, its
extra energy is emitted as an (em) wave. In an incandescent bulb, light is
emitted by electrons in hot tungsten atoms. In a fluorescent bulb, UV light is
emitted by electrons in a gas inside the bulb. The UV light is absorbed by
electrons in the bulb’s white coating. The electrons fall back down and emit
light.
Light and all (em) waves travel at a speed of 300 million meters per second.
Einstein proved that nothing can travel faster than the speed of light.
Materials and Setup
• Diffraction grating glasses
• Photoluminscent sheet
• Colored pencils or crayons
Scope and Sequence
14.2 Color
Learning Goals
• Describe the physical reason for
different colors in terms of the
wavelength and energy of light.
• Understand the mixing of light.
• Identify and explain the RGB color
model.
• Identify the parts of the eye that see
black and white, and color.
• Use a spectrometer to determine the
exact wavelengths of light.
• Identify and explain the CMYK color
model.
• Understand the mixing of light and
pigment.
• Compare how a color printer makes
color and how a color monitor makes
color.
Key question:
What happens when you mix different
colors of light?
Leading questions:
• Where does color come from?
• How does a color TV work?
• How does the human eye see color?
Reading Synopsis
Because light is a wave, it can be described by its frequency and wavelength.
Each color of light has its own exact frequency and wavelength. We can
recreate every color of light by mixing different combinations of red, blue,
and green light,the primary colors.
Our eyes contain rod cells and cone cells, which release chemical signals
when exposed to light. Rod cells respond only to brightness, and cone cells
respond to color. There are three kinds of cone cells, which react to red, blue,
and green light. The colors we see are how our brains interpret the signals
from these three kinds of cone cells.
Our eyes see light from light sources, and light that is reflected from objects
around us. In the case of light sources, we see the colors created by the colors
that are reflected from the object. Different objects absorb some frequencies
of light and reflect other frequencies of light, depending on their composition.
Materials and Setup
The optics kit
Spectrometer
Colored pencils or crayons
2 large sheets of paper or poster
boards
•
•
•
•
27
Scope and Sequence
15.1 Seeing an Image
Learning Goals
• Calculate the magnification level of a
lens.
• Plot the reflected rays from a mirror.
• Measure and compare the angles of
incidence and reflection from a mirror.
Key question:
What does magnification really mean and
how do you plot a reflected image?
Leading questions:
• How can you determine the magnification
of a lens?
• How does light interact with mirrors and
lenses to produce images?
• How can you plot a reflected image?
Reading Synopsis
Optics is the study of how light is bent and collected for the formation of
images and the transfer of information. In diagrams, light rays show the
direction of light. A light ray is an imaginary arrow that represents the path of
a light beam reflected or emitted from an object. A collection of light beams
forms an image. In diagrams, a collection of light rays indicates where an
image appears relative to a lens or mirror. An image is a place where many
rays from the same point on an object meet again in a point.
Optical systems, such as telescopes, contain lenses and mirrors that are used
to magnify or focus down the size of images. Geometry is used to analyze the
paths. Rays of light reflect from a mirror at an equal (but opposite) angle to
which they are incident on the mirror. Lenses refract light. Refraction is
bending of light as it enters a material that changes its speed.
Materials and Setup
• A convex, magnifying lens
• The optics kit (a laser with diffraction
filter and a flat mirror)
• A few sheets of white copy paper
• Colored pencils
• A protractor
• A metric ruler
Reading Synopsis
The human eye works with the optic nerve to form images that can be
interpreted by the brain. The parts of the eye include the lens, fovea, and rod
and cone cells. The lens of the eye focuses light on the fovea, a spot on the
retina at the back of the eye. Rod and cone cells, also at the back of the eye,
respond to light. Rod cells are sensitive to shades of grey, including black and
white. Cone cells are sensitive to color. The portion of light information
gathered by each of these special nerve cells is like a pixel on a computer
screen.
The image that forms on the fovea is upside down. The brain re-interprets this
image as right-side up. The lens of the eye moves and changes shape in order
to focus. Our ability to judge distances (also known as depth perception) is
possible because the brain receives two images, one from each eye. Images in
mirrors and optical illusions occur as they do because the brain interprets all
light as traveling in a straight lines. Reflected, angled light off the surface of a
mirror appears to come from an image in front of you.
Materials and Setup
• The optics kit: A small laser, a prism,
a protractor
• A sheet of white copy paper
• Colored pencils
• A protractor
• A ruler or straight edge
15.2 The Human Eye
Learning Goals
• Use and understand the rules of
refraction.
• Plot a ray through a lens.
• Calculate the index of refraction.
Key question:
How does a lens form an image?
Leading questions:
• Why is it possible to bounce a rock off of
water?
• What is total internal reflection?
• What is fiber optics technology?
28
Scope and Sequence
15.3 Optical Technology
Learning Goals
• Explain internal reflection.
• Demonstrate how to achieve internal
reflection in a material.
• Explain in simple terms how fiber optics
works.
• Identify uses of fiber optics.
Key question:
How are optics used in everyday life?
Leading questions:
• Why is it possible to bounce a rock off of
water?
• What is total internal reflection?
• What is fiber optics technology?
Reading Synopsis
Optical technology is the manipulation of light to transmit information or to
perform a useful function. Using lenses, light can be manipulated to improve
eyesight. Internet and telephone signals can be efficiently sent as laser light in
optical fibers.
Light carrying information enters a fiber within a small range of angles. Once
inside the fiber, the light does not escape because of total internal reflection.
Like a rock skipping along the surface of a pond, the light in the fiber skips
along the outer surface of the rod and stays inside. The light only hits the
outer surface of the fiber at large angles compared to the normal. A bundle of
fiber optics fibers carry information like images as a series of dots. The dots
of information are encoded as pulses of light.
In laser technology, electrons are stimulated so that they move to higher
energy levels and fall back from these at the same time. The light given off is
very concentrated.
Materials and Setup
• An optics kit
• A laser (with a diffraction filter)
• Triangular prism
• A sheet of blank, white copy paper
• Colored pencils (optional)
• A clear ruler
Additional objects should be available
in the class or lab for students to test for
total internal reflection. For example,
aquarium with water, pieces of
Plexiglas, or any other objects that are
clear. Try to have at least 15 or more
different objects.
The effects are best seen if the lights in
the classroom are off. If the classroom
is dark, you may want to have
flashlights
29
Scope and Sequence
16.1 Classifying Matter
Learning Goals
• Define matter.
• Classify matter as a heterogeneous or
homogeneous mixture, or as a
substance—either a compound or an
element.
• Recognize paper chromatography as one
technique used to separate a mixture.
• Recognize that identifying substances in
a mixture is important to many different
fields of science.
Key Question:
How can a homogeneous mixture be
separated?
Leading questions:
• What is matter?
• How is matter classified?
• What are some methods for separating
mixtures into their components?
30
Reading Synopsis
Matter is defined as anything that has mass and takes up space. Books, desks,
people, water, air are examples of matter.Matter can be divided into two
categories: mixtures and substances. Mixtures always contain more than one
kind of matter. There are two types of mixtures: homogeneous and
heterogeneous. Homogeneous mixtures are uniform throughout.
Heterogeneous mixtures are not necessarily uniform throughout. Different
samples may contain different proportions of ingredients. All mixtures can be
separated by physical means such as sorting, filtering, heating, or cooling.
Substances may contain one or more kinds of matter, but substances cannot
be separated by physical means. Substances that contain more than one kind
of matter are called compounds. Sodium chloride, or table salt, is a common
compound. Substances that contain only one kind of matter are called
elements.
Materials and Setup
• Three 10-by-3-centimeter strips of
chromatography paper
(filter paper or coffee filters, ironed
flat, are inexpensive, easy-to-find
alternatives)
• Overhead projector markers (waterbased ink), one each in black, blue,
and green
• Three 25-milliliter beakers or 8-ounce
clear plastic cups
• Centimeter ruler
• 3 craft sticks or coffee stirrers
• Tape
• Four permanently stoppered test
tubes: #1 sulfur powder; #2 iron
filings; #3 a small piece of iron
sulfide; and #4 a mix of iron filings
and sulfur powder
Scope and Sequence
16.2 Measuring Matter
Learning Goals
• Describe two ways to measure matter:
mass or volume.
• Demonstrate ability to find volume of
both regular and irregular solids.
Key question:
How is matter measured?
Leading questions:
• How do you measure mass and volume?
• How can you find the volume of an
irregular solid?
Reading Synopsis
Quantities of matter are measured in two distinct ways. Mass measurements
tell you how much material there is. Volume measurement tells you how
much space the material occupies.
A volume of liquid can be measured with a graduated cylinder. Many liquids
form a curve called a meniscus. The volume is read at the center point of the
curve.
Volumes of regular solids can be calculated using a formula, or measured by
displacement. To use the displacement method, the object is submerged in
water. The volume of water pushed aside by the object is equal to the volume
of the object.
Materials and Setup
• Balance, tools for measuring volume,
centimeter ruler
• Objects to measure (each group
should have a unique set of objects)
• Solid object such as a coffee mug,
beaker, key, toy block, large bolt
• Collection of 25-50 identical small
objects such as paper clips, macaroni
• Liquid such as a specific volume of
water, dish soap, corn syrup, or salt
water
• Liquid: specific mass of one of the
liquids above
• Regular solid such as shoe box, toy
block, soup can, paper cone,
racquetball (spheres are especially
challenging)
• Irregular solid such as key, pencil,
fruit, sunglasses, large paper clip
31
Scope and Sequence
16.3 States of Matter
Learning Goals
• Classify matter as mixtures or
substances, and substances as elements
or compounds.
• Compare the size of an atom with a
speck of dust or other microscopic
object.
• Give examples of materials that are
solid, liquid, or gaseous at room
temperature.
• Give evidence that matter is not gained
or lost in a change of state.
Key question:
How fast can you melt an ice cube?
Leading questions:
• What is meant by the term matter?
• What are the smallest particles of a
substance called?
• What is meant by a change of state?
• How do molecules move in each state of
matter?
32
Reading Synopsis
The smallest particle of a compound that retains the properties of the
compound is called a molecule. The smallest particle of an element that
retains its properties is called an atom.
Atoms and molecules are always in motion. In the solid state, atoms and
molecules constantly vibrate but cannot move from place to place. As a
result, solids retain their shape and size. In the liquid state, atoms and
molecules gain enough kinetic energy to slide past each other, but not enough
to separate from one another. Therefore, a liquid has a definite size, but no
definite shape of its own. In the gas state, atoms and molecules gain enough
kinetic energy to separate from one another. Therefore, the gas has no definite
size or shape of its own, but will spread evenly throughout a container.
When a substance changes from one state to another, only the movement of
the molecules changes. The number of molecules does not change.
Materials and Setup
Timer
Thermometer
One 150-milliliter beaker
One 400-milliliter beaker
Approximately 100 milliliters
crushed ice
• Warm water source
•
•
•
•
•
Scope and Sequence
17.1 Properties of Solids
Learning Goals
• Define density
• Use the formula mass divided by volume
to find density.
• Understand that density is a property
that can be used to help identify a
particular material.
• Identify these additional properties of
solids: hardness, elasticity, brittleness,
and malleability.
Key question:
How can you find the density of a solid?
Leading questions:
• What is the meaning of the term
“density”?
• Does density depend on the size or shape
of the material?
• Does density depend on the type of the
material?
• How can density be used to identify a
material?
• What are some other properties of solids?
Reading Synopsis
Different types of matter have different characteristics. These properties can
help us distinguish between types of matter, or help us decide which material
to use for a specific purpose. Some important properties of matter in its solid
form are density, hardness, elasticity, brittleness, malleability, and tensile
strength.
Density is the ratio of mass to volume in a homogeneous mixture or
substance. Density gives us information about the “compactness” of the
material.
Hardness measures a substance’s resistance to scratching. Elasticity measures
a solid’s ability to return to its original size when stretched. Brittleness
measures how easily a material will shatter. Malleability measures a solid’s
ability to be pounded into thin sheets. Tensile strength measures how much
pulling a material can withstand.
Scientists have studied each of these properties in order to invent new
materials to serve specific purposes.
Sequence: Students complete the reading after part five of the Investigation.
Materials and Setup
• Balance
• 100-milliliter graduated cylinder
• Six identical small objects: half of the
lab groups should have objects made
of one material, the other half should
have objects made of a second
material. The objects should vary in
size from group to group.
• Balance
• 100-milliliter graduated cylinder
• Approximately 100 pennies (minted
after 1962)
Reading Synopsis
The density of fluids is measured the same way as the density of solids: by
finding the ratio of mass to volume.
The density of fluids usually decreases as temperature increases. This is
because as the kinetic energy increases, the motion of the molecules or atoms
increases. This increased motion usually causes the molecules or atoms to
occupy a larger amount of space than they required in their solid form.
Water, however, is a notable exception. Water molecules have an unusually
large amount of empty space between them when they are arranged in their
solid form. The molecules actually take up less space in their liquid form. As
a result, ice is less dense than water. Ice cubes float in a glass of water, and ice
floats on the top of a pond.
Materials and Setup
• graduated cylinder
• balance
• 30 milliliters each of glycerin, corn
syrup, molasses, water, vegetable oil
• small objects (must easily fit inside
graduated cylinder): steel bolt, rubber
stopper, cork
• half-liter plastic bottle (the type in
which spring water is sold)
• 5 grams baking soda
• 50 milliliters vinegar
• balloon (9-inch diameter or larger
will fit over neck of half-liter bottle)
17.2 Density of Fluids
Learning Goals
• Calculate the density of various liquids.
• Construct a density column.
• Use a density column to predict the
density of a solid.
• State their observation that the density of
a liquid decreases as its temperature
increases, and formulate an explanation
using their knowledge of molecular
movement in liquids.
Key question:
Can you create a stack of fluids?
Leading questions:
• How do you find the density of a liquid?
• Does the density of a liquid change as its
temperature changes?
33
Scope and Sequence
17.3 Buoyancy of Fluids
Learning Goals
• Explain why a boat can be made of a
material that is more dense than water.
• Explain Archimedes’ principle.
• Calculate the buoyant force acting on an
object immersed in water.
Key question:
Can you make a clay boat float?
Leading questions:
• Why don’t boats made of steel sink?
• What is Archimedes’ principle?
• What is meant by the term “buoyant
force”?
• How can you measure the buoyant force
acting on an immersed object?
Reading Synopsis
Buoyancy is another important property of fluids. Buoyancy measures the
upward force that a liquid exerts upon an object. In the third century B.C.,
Archimedes discovered that the buoyant force is equal to the weight of the
fluid displaced by the object.
Archimedes’ principle can help us predict whether an object will sink or float
in a liquid. If the buoyant force is greater than the weight of the object, the
object will float. If the buoyant force is less than the weight of the object, then
the object will sink.
Steel boats can float because the boat is fashioned into a hollow shape that
displaces a much greater amount of water than a steel block would displace.
When the weight of the displaced water is greater than the weight of the steel,
the boat will float. Buoyancy is a property of gases as well as of liquids. A
helium balloon floats because it weighs less than the air it displaces.
Materials and Setup
• One stick of modeling clay
• Centimeter ruler
• Graduated cylinder
• Balance
• Beaker to collect displaced water
• Displacement tank
• Cup to catch water when refilling
• Paper towels, sponges, Wax paper
Optional:
• beakers, cups, displacement tanks,
and graduated cylinders
• Plastic wrap (the type used for food
storage)
• Plastic knife for teacher to mark boat
at water line during discussion
• spring scale, string, palm-sized rock,
and 500 ml beaker filled with water
Reading Synopsis
Viscosity is the third property of fluids. It is a measure of a material’s
resistance to flow. Viscosity is an important consideration in producing goods
such as food and oil.
The viscosity of a liquid is determined in large part by the size and shape of
its molecules. If the molecules are large and have bumpy surfaces, a great
deal of friction is created as the molecules slide past one another. The liquid
flows at a slower rate than a liquid made up of small molecules with a
smoother surface.
As the temperature of a liquid increases, its viscosity decreases. The
additional kinetic energy allows the molecules to slide past each other with
greater ease.
As the temperature of a gas increases, its viscosity increases. Because gas
molecules are far apart, they do not have to slide over each other often in
order to flow. Raising the temperature increases the number of collisions
between the molecules, resulting in an increase in friction and, therefore,
viscosity.
Materials and Setup
CPO Timer and two photogates
physics stand
one or two large rubber bands
ruler
100-milliliter graduated cylinder with
a removable base
• black, opaque glass marble
• 150 milliliters of one of these liquids
(each group will study a different
one): water, clear shampoo, vegetable
oil, glycerin, light corn syrup
• A copy of each student’s results from
the density of fluids Investigation
17.4 Viscosity of Fluids
Learning Goals
• Define viscosity.
• Measure viscosity.
• Describe how a molecule’s size, shape,
and temperature affect viscosity.
Key question:
How can viscosity be measured?
Leading questions:
• What is viscosity?
• How can viscosity be measured?
• How does a molecule’s size and shape
affect viscosity?
• How does an increase in temperature
affect viscosity?
34
•
•
•
•
•
Scope and Sequence
18.1 Atomic Structure
Learning Goals
• List the most important subatomic
particles that make up atoms.
• Describe the general spatial positions of
protons, neutrons, and electrons in
atoms.
• Describe the relative mass and electrical
charge of protons, neutrons, and
electrons.
Key question:
How was the size of an atom’s nucleus
determined?
Leading questions:
• Why are atoms the smallest piece that is
still recognizably matter?
• What do you find when you break apart
an atom?
Reading Synopsis
All matter is formed from atoms. Atoms, by themselves, or combined with
other atoms in molecules, make up everything that we see, hear, feel, smell
and touch. An individual atom is so small that a speck of dust contains
trillions of them.
Atoms and molecules are called the building blocks of matter because if you
attempt to break down an atom, you no longer have gold or water or any other
recognizable substance. If broken apart, almost all atoms contain three
smaller particles called protons, neutrons and electrons. Protons and neutrons
cluster together in the nucleus. The electrons move in the space around the
nucleus.
Subatomic particles have charge and mass. The proton is positive, the
electron is negative, and the neutron is neutral.
John Dalton published a detailed atomic theory that laid the groundwork for
later atomic models, and over time, his original theory has been expanded and
updated.
Materials and Setup
Marble or ball bearing
Sheet of carbon paper
Meter stick
One copy of the Skill Sheet,
“Materials for Investigation 18.1” in
the Reference Guide.
• Ruler, marked in millimeters
• Calculator
• Copies of the Skill Sheet, “Materials
for Investigation 18.1” as directed in
the Reference Guide
Reading Synopsis
Atoms are composed of protons, electrons and neutrons. The number of
protons distinquishes an atom of one element from an atom of another
element. Adding or removing a proton changes the type of atom. The atomic
number is equal to the number of protons.
The total number of protons and neutrons in the nucleus of an atom is called
the mass number. Many elements have atoms with different mass numbers.
These different forms of the same element are called isotopes.
Materials and Setup
• Atom Building Game
•
•
•
•
18.2 Comparing Atoms
Learning Goals
• Understand that each element is defined
by a name and by an atomic number,
which is the number of protons in each
atom of that element.
• Explain how an atom is held together by
the electrostatic force and the strong
nuclear force.
• Use the concept of electron shells to
arrange electrons in atomic models.
• Describe how positive and negative ions
are formed by the loss or gain of one or
more electrons by an atom.
Key question:
What are atoms and how are they put
together?
Leading questions:
• How does one kind of atom differ from
another kind of atom?
35
Scope and Sequence
18.3 The Periodic Table of Elements
Learning Goals
• Understand how elements are organized
in the periodic table.
• Identify the atomic number and mass
numbers of each element in the periodic
table.
• Calculate the numbers of protons and
neutrons in each stable isotope of an
element.
Key question:
What does atomic structure have to do with
the periodic table?
Leading questions:
• What are all of the elements that we know
about?
• Do some elements have properties in
common?
• How can we keep track of the elements
and their properties?
36
Reading Synopsis
Before people understood the internal structure of the atom, they were able to
identify elements by how they acted chemically. Since the eighteenth century,
scientists have been motivated to identify and catalog all of the elements that
make up the universe. Elements are substances that cannot be broken down
into smaller substances. We now know of 111 different kinds of elements, and
the search for new ones continues. The elements are organized, based on their
chemical and physical properties, into the Periodic Table of the Elements.
The arrangement of each element in the periodic table already conveys a lot
of information about it. The individual listing of each element in the periodic
table provides the name of the element and its symbol, the number of protons,
the mass of the element relative to the mass of a carbon 12 atom (the atomic
mass) and the mass number which describes how many protons plus neutrons
are in the nucleus.
Materials and Setup
• Periodic Puzzle
• Blank periodic table
• Atom Building Game
Scope and Sequence
19.1 Bonding and Molecules
Learning Goals
• Explain how and why atoms form
chemical bonds.
• Identify the types of bonds in molecules.
• Build accurate models of atoms.
Key question:
Why do atoms form chemical bonds?
Leading questions:
• Why do atoms form compounds?
• What are the different types of chemical
bonds?
• How can you tell what kind of bonds a
molecule has?
Reading Synopsis
Most of the substances in the universe are in the form of compounds. If a
substance is made of a pure element for example, an iron nail is made of pure
iron, it will eventually react with another element to form a compound. This
is why an iron nail will rust. Some elements are so reactive, that if they come
into contact with air, the will react violently and cause an explosion. Some
elements will not react with other elements very easily, for example, the
Noble Gases. Students learn why and how elements react with other elements
to form compounds, how electrons are involved in the formation of chemical
bonds and how the organization of elements in the periodic table are related
to the number of electrons an atom has in its outermost energy level. These
outermost electrons are called valence electrons. The most stable atoms have
eight valence electrons while unstable atoms have less than eight. Atoms will
gain or lose electrons and form chemical bonds with other atoms to become
stable.
Materials and Setup
• One Atom Building Game
• One Periodic Table that comes with
the game
• For part of the Investigation, two
groups will combine so that they have
two Atom Building Games.
Reading Synopsis
When two atoms form a chemical bond, the ratio in which they combine is
related to the number of valence electrons each atom has. The ratios which
the atoms combine determines the chemical formula of the compound.
Ionic compounds are made out of positive and negative ions. The chemical
formulas of ionic compounds can be determined from the oxidation numbers
of the ions from which they are made. For the elements, the most common
oxidation numbers can be determined by identifying the group number for
each element. Some ions are made out of more than one type of atom. These
are called polyatomic ions.
Naming ionic compounds involves writing the name of the positive ion first,
followed by the name of the negative ion.
Covalent compounds are made from covalently bonded atoms.
Materials and Setup
• One Periodic Puzzle
19.2 Chemical Formulas
Learning Goals
• Explain the relationship between the
placement of elements on the periodic
table and chemical formulas.
• Explain how the charge of an ion is
determined.
• Write and name the formulas for
compounds.
Key question:
Why do atoms combine in certain ratios?
Leading questions:
• What is the relationship between the
placement of elements on the periodic
table and chemical formulas?
• How is the charge of an ion determined?
37
Scope and Sequence
19.3 Comparing Molecules
Learning Goals
• Explain the meaning of a chemical
formula in terms of number of atoms,
atomic mass and formula mass.
• Write the empirical and molecular
formula for a compound and explain the
difference.
• Apply what they have learned to solving
a more complex problem.
Key question:
What is the meaning of a chemical formula?
Leading questions:
• How many different compounds can be
made from the same two atoms?
• How can you figure out the chemical
formula of a substance if you know the
mass of each type of atom in the
substance?
• What is the difference between an
empirical formula and a molecular
formula?
38
Reading Synopsis
Does a molecule of water have the same mass as a molecule of calcium
carbonate? Likewise, if you have ten grams of water and ten grams of calcium
carbonate, does each sample contain the same number of molecules? The
answer to both of these questions is no because the atoms of each element on
the periodic table are assigned a unit of relative mass called the atomic mass.
If you add up the atomic masses of each atom in a molecule, you get the
formula mass, in atomic mass units, of that compound. The formula mass of a
molecule of water is 18.02 atomic mass units while the formula mass of a
molecule of calcium carbonate is 100.9 atomic mass units. Avogadro’s
number (6.02 x 1023) allows us to work with larger amounts of substances
instead of working with molecules and atoms. The Avogadro number of
molecules of water would have a mass of 18.02 grams and the same number
of molecules of calcium carbonate would have a mass of 100.9 grams. Each
of these amounts is equal to one mole of that substance.
Materials and Setup
• 10 bolts, each at least 2 inches long
• 10 nuts, the same size diameter as the
bolts
• 1 “mystery box”
• electronic balance
• 1 large matchbox per student group
(large enough to hold several
“molecules” made out of nuts and
bolts
• Labels that fit on the matchbox
• Nuts and bolts (enough to assemble
several molecules for each student
group)
Scope and Sequence
20.1 Chemical Changes
Learning Goals
• Identify the differences between
chemical and physical changes.
• Identify the role of chemical and
physical changes in nature.
• Observe and carry out a series of
chemical reactions.
• Develop a list of evidence for
determining the occurrence of chemical
changes.
Key question:
What is the evidence that a chemical change
has occurred?
Leading questions:
• What are the differences between
chemical and physical changes?
• What is the role of physical and chemical
changes in nature?
Reading Synopsis
There are different types of changes in matter that occur. We can classify
changes in matter as either chemical changes or physical changes.
A physical change is a change that affects only the physical properties of a
substances including size, shape and physical state. Examples of physical
changes include: ice melting, chewing food and crushing glass.
A chemical change is a change that alters the chemical properties of a
substance. Atoms are rearranged in compounds when a chemical change
occurs and the result is a new substance with different physical and chemical
properties. Chemical changes are the result of chemical reactions; that is, the
breaking of bonds in one or more substances and the reforming of new bonds
in new substances. Examples of chemical changes include: rust forming,
digestion of food and combustion of fuels.
Materials and Setup
• 4 plastic sandwich bags that can be
securely sealed
• permanent marker for marking the
bags
• 5 grams of Epsom salts (magnesium
sulfate)
• 50 mL of household ammonia
(ammonium hydroxide)
• 50 mL of hydrogen peroxide (H2O2)
• slice of potato
• 10 grams of baking soda
• 10 mL of red cabbage juice
• 5 grams of calcium chloride
• glow stick
• charcoal-activated heat pack
• goggles and lab apron per student
Reading Synopsis
A chemical reaction involves the rearrangement of atoms in one or more
substances to make one or more new substances. A chemical equation is a
“recipe” for a chemical reaction. Chemical equations use symbols and
chemical formulas to represent what happens during a chemical reaction.
A chemical equation is written so that the reactants are on the left side of the
equation, followed by an arrow, and then the products are written on the right
side of the arrow.
Chemical equations obey the laws of conservation. The number and type of
atoms on the reactants side of the equation must be exactly equal to the
number and type of atoms on the products side. If these numbers do not add
up correctly, the equation must be balanced by inserting coefficients in front
of the substances in the equation. Balancing an equation is a trial and error
process that results in an equal number and type of atoms on both sides of the
chemical equation.
Materials and Setup
• One Periodic Puzzle
20.2 Chemical Equations
Learning Goals
• Write word and chemical-formula forms
of chemical equations.
• Balance chemical equations.
Key question:
How do you balance chemical equations?
Leading questions:
• How are chemical equations written and
represented?
• How are atoms conserved in a chemical
reaction?
39
Scope and Sequence
20.3 Conservation of Mass
Learning Goals
• Explain and justify the law of
conservation of mass.
• Design a simple experiment and present
results of an experiment to a group.
Key question:
How can you prove that mass is conserved
in a reaction?
Leading questions:
• What is the law of conservation of mass?
• How can you prove that the law of
conservation of mass is true?
Reading Synopsis
In the eighteenth century, a French scientist named Antoine Lavoisier
established an important principle based on his experiments with chemical
reactions known as the law of conservation of mass. This law states that the
total mass of the reactants in a chemical reaction must be exactly equal to the
total mass of the products.
Lavoisier used a closed system, one in which he carefully controlled all
inputs and outputs, to prove this important law.
Materials and Setup
• At least two effervescent cold
medicine or antacid tablets
• Water
• 2 250 mL beakers
• Small calculator
• 2 baggies with zippers
• 2 plastic pipets
• electronic balance
Reading Synopsis
A chemical equation is like a recipe because it tells you the ratios of each of
the ingredients and products. It is unlike a recipe because it does not tell you
the exact amounts of the ingredients to produce an exact amount of products.
It also does not give you specific directions on how to carry out the reaction.
The ratios are determined by the coefficients in the balanced equation.
When a chemical reaction occurs, the reactant that is used up first is called the
limiting reactant. Other reactants that are left over are called excess reactants.
Because it is used up first, the limiting reactant determines the amount of
product formed.
Not all reactions turn out as planned. This is because there are many other
complex factors involved in a reaction. When most reactions occur, the
percent yield is less than one hundred percent of product produced to limiting
reactant used.
Materials and Setup
• sodium hydrogen carbonate (baking
soda), 10 grams total, divided into 5,
2 gram samples. Each sample can be
placed into a small paper cup (1oz)
• acetic acid (vinegar): about 250 mL
• two 250 mL beakers, one labeled “A”
and one “B.” (Students will need 6
beakers if they can’t wash out beaker
A between trials.)
• periodic table
• digital balance, accurate to 0.1 gram
• small calculator
20.4 Using Equations as Recipes
Learning Goals
• Identify the relationship between the
amount of reactants and amount of
products in a reaction.
• Develop a rule for predicting the mass of
product given the mass of the limiting
reactant.
Key question:
How can you predict the amount of product
in a reaction?
Leading questions:
• What does a balanced chemical equation
tell you about a chemical reaction?
• What is a limiting reactant?
40
Scope and Sequence
21.1 Classifying Reactions
Learning Goals
• Identify the main types of chemical
reactions.
• Predict the products of a reaction.
• Predict whether or not a product will be
soluble or insoluble using solubility
rules.
Key question:
How can you predict the products in a
reaction?
Leading questions:
• What are the main types of chemical
reactions?
• How can you predict the products of a
reaction?
• What is a precipitate?
Reading Synopsis
Chemical reactions can be classified into different categories. In an addition
reaction, two or more substances combine to form a new substance.
A decomposition reaction involves the breaking down of one substance into
two or more new substances.
Single-displacement reactions occur when one element takes the place of
another element in a compound.
In a double-displacement reaction, two ionic compounds form ions in
solution and exchange places to form two new ionic compounds. When this
type of reaction occurs, new compounds that are insoluble (do not dissolve in
water) settle out as precipitates.
Combustion reactions occur when a substance such as wood or hydrocarbons,
combines with oxygen gas to produce carbon dioxide, water and lots of heat
and light.
Materials and Setup
• A set of six labeled solutions of
household chemicals, in 50 mL
beakers (See Teacher’s Guide for a
list of these chemicals and
instructions for mixing them.)
• One clear reaction plate
• Six pipettes (one per reaction
solution)
• A periodic table
Reading Synopsis
When a chemical reaction takes place, chemical bonds in the reactants are
broken and reformed to make new products. To break bonds requires energy.
When new bonds form, energy is released. When more energy is required to
break the bonds in a reaction than is released when new bonds are formed, the
reaction is called endothermic. Endothermic reactions can be detected by a
decrease in temperature during the reaction.
When more energy is released in the formation of new bonds than is required
to break the bonds in the reactants, the reaction is called exothermic.
Exothermic reactions can be detected by an increase in temperature during
the reaction.
A dissolution reaction occurs with an ionic compound dissolves in solution.
Dissolution reactions require energy because ionic bonds are being dissolved.
Materials and Setup
3-250 mL beakers
1 stirring rod
1 thermometer
water
30 grams of ammonium nitrate (find
out the common name)
• 150 mL of hydrogen peroxide
• 1 slice of potato (freshly sliced)
• 30 grams of calcium chloride (snow
melt)
21.2 Energy in Reactions
Learning Goals
• Distinguish between exothermic and
endothermic reactions.
• Describe the energy changes that occur
in reactions.
• Represent energy changes in a chemical
equation.
Key question:
How can you classify reactions based on
energy?
Leading questions:
• How do you measure energy changes in
reactions?
• How does energy change in a reaction?
• What are exothermic and endothermic
reactions?
•
•
•
•
•
41
Scope and Sequence
22.1 Nuclear Reactions
Learning Goals
• Distinguish between a nuclear and
chemical reaction
• Know the difference between fusion and
fission
• Know the difference between the
different types of radioactive decay
(alpha, beta, and gamma decay).
• Understand the meaning of half-life.
Key question:
How do you simulate nuclear decay?
Leading questions:
• What is the difference between a chemical
and a nuclear reaction?
• What is the difference between fusion and
fission?
• What is the role of nuclear chemistry in
technology, industry, medicine, and
energy production?
Reading Synopsis
There are two main types of reactions in which atoms participate. Chemical
reactions, the most common type of reaction, involve outermost electrons.
However, the nucleus of an atom can also participate in what are called
nuclear reactions. The nucleus of a radioactive atom can split in a process
called fission or a nucleus can combine with another nucleus in a process
called fusion. Fission and fusion produce a great deal of energy. This is
because a great deal of force (called strong nuclear force) keeps the nucleus
together. Radioactive decay is spontaneous fission that involves the emission
of particles (alpha and beta) and energy (gamma radiation) from the nucleus
of a radioactive isotope. The sun’s energy comes from fusion reactions
involving hydrogen. Nuclear reactors can be used to control and utilize the
energy produced in nuclear reactions. However, storing radioactive waste is
problematic. The radioactive isotopes used for fuel in reactors have long halflives. A half-life is the length of time it takes for half the number of
radioactive atoms to decay.
Materials and Setup
• 100 pennies in a jar
• a tray or box to collect the pennies
when they are poured out
• graph paper
Reading Synopsis
The sun provides about 99% of the energy we use. Much of the rest comes
from burning fossil fuels. This fuel and our nutritional fuel (food) are
ultimately derived from plants. Plants use the sun’s energy, CO2 and H2O, to
make sugars that are converted into food, wood and other hydrocarbons. In
addition to sugar, O2 is produced in photosynthesis. Plants help keep O2
levels in the atmosphere at 21%. The products of respiration (somewhat the
reverse of photosynthesis) are CO2 and H2O. Respiration is the way your
body gets energy from food and it is similar to the combustion of fossil fuel in
a car. The CO2 produced by combustion reactions in cars and industry is
causing CO2 levels in the atmosphere to increase. CO2 traps heat leading to
global warming. Because plants use CO2, they may help alleviate global
warming. However, a sure way to alleviate global warming pressures is to
reduce our use of fossil fuels.
Materials and Setup
• ACEEE’s Green Book™: The
Environmental Guide to Cars and
Trucks
• calculators for each student
22.2 Carbon Reactions
Learning Goals
• Write out the equations for
photosynthesis, respiration, and
combustion.
• Understand how the equations for
photosynthesis and respiration are
related.
• Understand the environmental effects of
using of fossil fuels.
Key question:
How do your choices impact the
environment?
Leading questions:
• What is the composition of Earth’s
atmosphere?
• What is a combustion reaction?
• What is global warming?
42
Scope and Sequence
23.1 What is a Solution?
Learning Goals
• Explain the differences among solutions,
colloids, and suspensions.
• Categorize mixtures as solutions,
colloids, or suspensions.
Key question:
How do you identify mixtures as solutions,
suspensions, or colloids?
Leading questions:
• What is a solution?
• How are solutions, colloids, and
suspensions different?
Reading Synopsis
A solution is a mixture of two or more substances that is homogeneous at the
molecular level. A solution can be made from solid, liquid, and/or gas
components. The substance present in the greatest amount is generally known
as the solvent. The other components are called solutes.
Colloids and suspensions are two types of mixtures that may look like
solutions, but do not meet all of the requirements. Suspensions will settle
upon standing and can be filtered. Colloid particles will scatter light, a
property known as the Tyndall effect.
Materials and Setup
• shoe box
• 3 large sheets black construction
paper
• glue stick or scotch tape
• a permanent marker for labeling
• utility knife or scissors
• centimeter ruler
• flashlight (or laser pointer)
• eight 250-milliliter heat-resistant
glass beakers
• about 10 coffee stirrers
• mortar and pestle for grinding
• 2 or 3 pieces of chalk
• 40 milliliters corn oil
• food coloring
• 2.5 grams corn starch
• 9 grams granulated sugar
• 3 grams modeling clay
• 2.5 grams plain gelatin
• heat source for boiling water
• filter paper (coffee filters work well)
graph paper, scissors
43
Scope and Sequence
23.2 Dissolving Rate
Learning Goals
• Define and calculate dissolving rate.
• List factors that influence dissolving
rate, and explain on a molecular level
how each factor works.
• Evaluate the effectiveness of three
different methods of influencing
dissolving rates.
Key question:
How can you influence dissolving rates?
Leading questions:
• What is the definition of “dissolving
rate”?
• How is dissolving rate calculated?
• What factors influence dissolving rate?
Reading Synopsis
The dissolving rate of substances can be influenced in several ways. Two
methods are introduced in this Investigation. The first is by increasing
molecular motion. Stirring or shaking a mixture increases the energy of
solute-solvent collisions. It also brings fresh solvent in contact with the
solute. As a result, the solute enters the solution at a faster rate than if the
mixture was undisturbed.
A second method of increasing the dissolving rate is to increase the surface
area of the solute which is in contact with the solvent. This can be
accomplished by cutting or crushing the solute before placing it into the
mixture.
Materials and Setup
approximately 25 grams rock salt
graduated cylinder
balance or scale to measure mass
source of room-temperature water
three 500-milliliter beakers
three glass jars with lids (minimum
capacity 300 milliliters)
• CPO timer set to stopwatch mode
• calculator
• stirring rods
• wire or nylon screens of different size
for separating pieces of rock salt
• hammer with paper towels
• small zipper-lock plastic freezer bags
Optional for demonstration:
• One cube-shaped cake (bake in 9X9
• cake knife, spatula waxed paper
• paper napkins (one per student)
Reading Synopsis
Solute molecules and solvent molecules form a system that can be influenced
by certain factors. Solubility is the amount of solute that can dissolve in a
certain amount of solvent under certain conditions. Usually, as temperature
increases, so does the solubility of a solid in a liquid. The solubility of a gas in
a liquid tends to increase as temperature decreases and pressure increases. If
temperature is held constant, the amount of gas that can dissolve in a solution
will increase in proportion to the increase in pressure.
Collisions between solute and solvent molecules are necessary for dissolving
the solute. There is a limit to how much solute will dissolve in a solvent. A
solution is saturated when no more solute can dissolve. At this point,
equilibrium has been reached. Solubility values tell you how much of a solute
will dissolve in a given amount of solvent at a given temperature.
Temperature-solubility graphs offer a quick way to determine the solubility
values for substances.
Materials and Setup
• 50 milliliters each of ice water, roomtemperature water, and hot water
• 3 glass 100-milliliter beakers (either
graduated or marked at the 50milliliter level)
• 3 styrofoam cups for collecting the
water samples
• 6 - 10 sugar cubes
• water-soluble marker
• thermometer or temperature probe
• drawing paper
•
•
•
•
•
•
23.3 Solubility
Learning Goals
• Explain the factors that influence
solubility.
• Explain how and why temperature
affects dissolving rate.
• Understand that there is a limit to how
much solute can dissolve in a solvent for
a given set of conditions.
Key question:
How does temperature affect solubility?
Leading questions:
• What does solubility mean?
• How does temperature influence
solubility?
• How do substances dissolve?
44
Scope and Sequence
24.1 Water
Learning Goals
• Understand some of the properties of
water
• Understand what factors are important
to water quality.
• Use and interpret basic water quality
tests.
Key question:
What is the quality of your tap water?
Leading questions:
• What is the nature of water?
• What is the source of water for my
community?
• How is water quality measured?
Reading Synopsis
Water is considered to be a universal solvent. The properties of water are due
to its unique structure. It is a “V” shaped molecule with an oxygen (O) atom
at the point of the “V”. Two oxygen-hydrogen (O-H) bonds form the legs of
the “V”. The O atom has a higher electronegativity value than hydrogen (H)
and “pulls” on the electrons in the O-H bond. For this reason, O has a partial
negative charge. By comparison, the H atoms have a partial positive charge.
Because of the partial charges, a water molecule is described as being polar.
The polar nature of water means that is can dissolve ions and other polar
molecules. Molecules that do not have charge separation (i.e., oils, fats, and
waxes) are nonpolar and do not dissolve in water.
In a volume of water, individual molecules orient so that the negative ends of
one molecule associate with the positive ends of the neighboring
molecules.This connection is called a hydrogen bond.
Materials and Setup
• 1 or 2 graduated cylinders
• paper towels
• hot water and cold water sample
(brought from home)
• 10 glass 50-milliliter beakers, test
tubes or plastic bags
• Two each of the water quality testing
tablets for testing pH, water hardness,
copper levels, lead levels, and
chlorine levels
Reading Synopsis
The water cycle keeps water moving around the planet. In other words, a
puddle on the street today eventually becomes water in an aquifer (this water
is called groundwater) or it becomes water vapor in the atmosphere. The four
parts of the water cycle are evaporation (water to vapor), transpiration (water
released by plants), condensation (vapor to raindrops), and precipitation (rain
or snow). The sun drives the water cycle. Cloud seeding is a way to increase
that chances that rain will fall. This procedure is very important in areas
where rain can be scarce, but greatly needed for growing crops.
Of the water on Earth, less than 1% is available in the form of fresh water for
our use; the rest is in the oceans or at the poles. For this reason, we need to
work on taking care of the water we have. Water quality tests help us do that.
Materials and Setup
• data sheets (made up ahead of time)
• clipboards and pencils
• sampling jars with lids (preferably
sterile)
• sampling and test materials from the
water quality test kit
• a Secchi disk (optional)
• Trash bags (for trash)
• Moist towelettes (for students to
clean their hands once they have
finished working with the water
quality test)
Duration: Two or more class periods
plus additional time for preparing for
the field trip and for analyzing data
after the field trip tablets)
24.2 The Water Cycle
Learning Goals
• Describe how water moves through the
water cycle.
• Explain why maintaining our water
quality is important.
• Understand and perform standard water
quality tests.
Key question:
What is the quality of your local surface
water?
Leading questions:
• What is the water cycle?
• How is water distributed on Earth?
• How is water quality measured?
45
Scope and Sequence
25.1 Acids, Bases, and ph
Learning Goals
• Describe pH as a way to measure the
strength of acids and bases (alkalis).
• Understand that acids are chemicals that
contribute H+ ions to a solution.
• Understand that bases (alkalis) are
chemicals that contribute OH- ions to a
solution.
• List several common household
chemicals that are acidic and basic.
Key question:
What is pH?
Leading questions:
• What does pH mean?
• What is the pH scale?
• How can we measure pH?
46
Reading Synopsis
Life exists inside a certain range of pH values. Many biological reactions
(such as digestion) function at certain pH values. Your breathing rate is
influenced by whether or not your blood pH is 7.35 - 7.45.
A pH value describes whether a solution is acidic, basic (alkaline), or neutral.
Acids are solutions that contain a majority of H+ ions. Bases are solutions
that contain a majority of OH- ions. Neutral solutions, like water, have equal
numbers of H+ and OH- ions. In this sense, water is both a weak acid and a
weak base. Hydrochloric acid is a strong acid, whereas vinegar is an example
of a weak acid. Sodium hydroxide is a strong base and household ammonia is
a weak base.
The pH scale ranges from 1 to 14 with acids being in the range of 1 to less
than 7, and bases being in the range of more than 7 to 14. For each level going
down the pH scale (starting at 14 and going down), the concentration of H+
ions increases by a factor of 10 and the concentration of OH- decreases by a
factor of 10.
Materials and Setup
spot plates (students need 12 wells)
permanent markers for labeling
eyedroppers or pipettes
5 milliliters of red cabbage juice pH
indicator
• 12 pieces of red litmus paper
• 12 pieces of blue litmus paper
• 2 milliliters of each of the following:
lemon juice, vinegar, seltzer, red
cabbage juice pH indicator, baking
soda solution, hand soap solution, and
household ammonia
• 2 milliliters of each of the following:
Green tea, antibacterial cleaner, apple
juice, mystery solutions
• Red Cabbage Juice pH indicator
• Baking soda solution:
Dissolve 1/2 teaspoon of baking soda
in 500 milliliters of water.
• Hand soap solution
•
•
•
•
Scope and Sequence
25.2 Acid Rain
Learning Goals
• Define acid rain.
• Explain the causes of acid rain.
• Explain why distant areas can
experience acid rain even if the source
of the cause is far away.
• List the environmental consequences of
acid rain.
• Identify ways in which acid rain can be
addressed and prevented.
Key question:
What is acid rain?
Leading questions:
• What is acid rain?
• What causes acid rain?
• What are the environmental consequences
of acid rain?
Reading Synopsis
Rainfall and other kinds of precipitation are naturally acidic. This is because
water vapor in the atmosphere is acidified when it mixes with carbon dioxide
forming carbonic acid. Acid rain or acid precipitation is defined as rain, snow
or fog that has a pH lower than 5.6.
Nitrogen and sulfur oxide emissions from combustion reactions in cars or
industrial processes cause acid rain. The nitrogen and sulfur oxides mix with
water vapor in the atmosphere to form nitric and sulfuric acids. Wind patterns
can transport these acids at great distances from the source of production.
Acid rain affects the health of people, trees and aquatic life. Buildings and
statues are eroded by acid rain.
Alternative means of transportation such as bicycling, and mass transit can
help reduce emissions that cause acid rain.
Materials and Setup
• One 100-milliliter vial with 80
milliliters of distilled water and at
least 6 Daphnia individuals
• A control vial with 10 milliliters of
distilled water and a vial for each of
the five treatment solutions: 1:50,
1:100, 1:500, 1:1000, 1:5000
• 2 wide-bore pipettes for transferring
Daphnia
• 1 to 2 magnifying glasses
• 1 to 2 rulers
• A watch (digital or second hand)
• 6 pieces of wide-range pH paper or
pH color indicator tablets
• A piece of white paper to place
behind the vials to help the students
better see the Daphnia
47
Scope and Sequence
26.1 Temperature Scales
Learning Goals
• Measure temperature.
• Convert between temperature scales.
• Understand and demonstrate physical
changes due to temperature.
Key question:
How is temperature measured?
Leading questions:
• What physical properties change with
temperature?
• How do you use these properties to design
a temperature measurement device (i.e.
thermometer)?
Reading Synopsis
We use temperature to quantify the sensations of hot and cold. When you
measure the temperature of a cup of water, you are actually measuring the
average of the kinetic energies of all the molecules of water in the cup. When
heated, the water molecules move faster and faster. The average kinetic
energy increases and the temperature goes up.
The Fahrenheit and Celsius scales are used to measure temperature. The
expansion of the liquid in common thermometers is directly proportional to
the change in temperature. Digital thermometers measure changes in
electrical resistance rather than expansion of a liquid. The increased electrical
resistance measured by digital thermometers is directly proportional to the
change in temperature.
The fact that materials expand when temperature increases can be used to
explain why civil engineers design expansion joints in bridges, and how
thermostats work.
Materials and Setup
• A Celsius thermometer and a
Fahrenheit thermometer
• Cups
• Ice
• Water
• Hot plate or heating element
Reading Synopsis
Electrical energy can be converted to thermal energy. Thermal energy is the
total energy stored in an object due to differences in temperature. Thermal
energy depends on three things: the mass of an object, its temperature, and
how well the object heats up. When thermal energy flows from place to place,
this moving energy is called heat. Objects contain thermal energy, but they do
not contain heat. However, heat can be added to an object so that its
temperature increases.
The specific heat of a substance indicates how much the temperature of an
object will rise when heat is added. Heat can be measured in calories, joules
or British Thermal Units (Btus). A calorie is the quantity of heat needed to
increase the temperature of 1 gram of water by 1°C. One calorie is equal to
4.184 joules. A Btu is the quantity of heat used to increase the temperature of
1 pound of water by 1°F.
Materials and Setup
Thermometer
Insulated beaker
Graduated cylinder
Immersion heater and access to an
electrical outlet
• Water
• Stopwatch
• Goggles
26.2 Measuring Changes in Heat
Learning Goals
• Develop a relationship for how much the
temperature of water increases by
adding heat to the water.
• Discuss the relationship of heat and
energy.
• Calculate the efficiency in a heating
system.
Key question:
How efficient is an immersion heater?
Leading questions:
• How is energy conserved in a system?
• What is thermal energy?
• How does heat increase the temperature of
an object?
48
•
•
•
•
Scope and Sequence
26.3 Specific Heat
Learning Goals
• Predict the final temperature when two
containers of water of different
temperatures are mixed.
• Quantify the flow of heat from one
container of water to another where
there is an initial temperature difference
between the two containers.
• Analyze temperature changes in terms
of the flow of heat.
• Calculate the specific heat of a second
substance if a known quantity is mixed
with water.
• Predict the equilibrium temperature of a
mixture of water and a second
substance.
Key question:
How much heat flows between liquids at
different temperatures?
Leading questions:
• What is thermal equilibrium?
• What is the flow of heat?
• How does the flow of heat change the
temperature of objects?
• What is specific heat?
• How do you calculate specific heat?
Reading Synopsis
When a hot object or substance is in thermal contact with a cold object or
substance, heat will flow from the hot object to the cold one until both are the
same temperature. At this point, the objects are in thermal equilibrium. As
heat is transferred, energy is also transferred. The amount of energy lost, is
always equal to the amount of energy gained. This concept is called the law of
conservation of energy. This law is also called the first law of
thermodynamics.
When a certain amount of heat is transferred to a set of objects, the amount of
temperature increase for each object will be different. The amount of
temperature increase is a value called specific heat. Water has a high specific
heat. This means that a volume of water absorbs a lot of heat, before its
temperature will raise. The specific heat of water is 1 calorie/gram °C.
Specific heat is directly related to density. The more atoms in a gram of a
substance, the more energy it takes to raise the temperature of that substance.
This is called the law of Dulong and Petit.
Materials and Setup
3 cups
Mixing beaker
Graduated cylinder
Thermometer
Cold and hot water
Alcohol (isopropyl rubbing)
Stirring rod
Goggles
•
•
•
•
•
•
•
•
49
Scope and Sequence
27.1 Conduction
Learning Goals
• Describe how thermal energy is
transferred by conduction.
• List what kinds of materials are heat
conductors and insulators.
• Explain why thermal and electrical
conductivity of a material are related.
Key question:
How well do common materials conduct
heat?
Leading questions:
• How is heat transferred from one material
to another, or from one place to another?
• What materials do we use to keep things
warm or cold?
Reading Synopsis
Thermal energy travels as heat from a material at a higher temperature to a
material at a lower temperature. This general process is called heat transfer.
One of the three mechanisms of heat transfer is conduction. Conduction is
heat transfer by the direct contact of particles of matter. It occurs between two
materials at different temperatures when they are touching each other. The
atoms in the hotter material have more kinetic energy. This energy is
transferred to the cooler material by the collisions of atoms until thermal
equilibrium is reached and both materials have the same temperature.
Materials that conduct heat easily are called thermal conductors, and those
that conduct heat poorly are thermal insulators. Thermal conductors tend to
be dense, metallic and can conduct electricity (due to having free electrons).
Thermal insulators tend to be less dense. The degree to which something can
conduct heat is measured as a value called thermal conductivity.
Materials and Setup
• Several pieces of styrofoam, plastic,
cardboard and metal (and any other
material available) that students can
touch with their whole hand (items
such as metal desks can be used). All
materials should be at room
temperature.
Extension Activity:
• Access to a recent newspaper and
calculators
Reading Synopsis
Convection is a type of heat transfer that occurs only in fluids (liquids and
gases). This process of heating occurs because warmer fluids are less dense
and rise. Cooler fluids are more dense and sink. This temperature-based
motion of fluids causes fluid currents and circulation.
There are two types of convection: natural and forced. Natural convection
causes global weather patterns and ocean currents. In cooking, convection is
essential for heating pots of liquid. Natural convection occurs when less
dense, warm fluid displaces more dense cool fluid and vice versa so that fluid
circulation results. In forced convection, a mechanical device (like a fan or
pump) is used to force the air or liquid to move. Warm fluids can carry heat to
cooler regions. Likewise, forced convection can be used for cooling. Moving
cool fluids can take heat from hot regions. Most homes are heated and cooled
using a combination of natural and forced convection.
Materials and Setup
27.2 Convection
Learning Goals
• Analyze how energy can be transferred
through convection.
• Describe the motion of liquid because of
temperature differences within the
system.
• Describe applications of convection.
Key question:
How much heat is transferred through
convection?
Leading questions:
• What is convection?
• How can energy be transferred by the
process of thermal convection?
• What is the difference between natural
and forced convection?
• What are some examples of convection?
50
•
•
•
•
•
Flask
Stopwatch
Food coloring
Stirring rod
Digital thermometer (necessary for
measuring small temperature
differences)
• Graduated cylinder
• Hot and cold water
• 2-hole rubber stopper and glass
tubing
• A large beaker
• Paper towels
• Drinking straws
Scope and Sequence
27.3 Radiation
Learning Goals
• Explain what properties make a good
radiation absorber.
• Explain the color-temperature
relationship.
Key question:
Which materials are good absorbers of
radiation?
Leading questions:
• What kind of radiation does an object emit
at a given temperature?
• What properties make an object a good
absorber?
• What properties make an object a good
emitter?
Reading Synopsis
Radiation is heat transfer by electromagnetic radiation that occurs in the
presence or absence of matter. Radiation is the only way that heat can travel
through space (a vacuum) from the sun to Earth. Heat transfer by convection
and conduction occur only in the presence of matter.
Objects emit radiation according to their thermal properties or internal
energy. Radiation can be in the form of visible light or invisible forms of light
such as infrared or ultraviolet. A color-temperature relationship exists for
objects that emit visible light. For example, the temperature of stars is be
determined by spectral diagrams that show the range of colors emitted by an
object. Warm stars have peaks of blue in their spectral diagrams, cold stars
have peaks of red.
Radiation is reflected or absorbed by varying degrees from objects. Objects
that are good reflectors are shiny and metallic, or light colored. Good
absorbers are dark colored. Objects can re-emit heat by radiation, conduction,
or convection.
Materials and Setup
• 100-watt light bulb
• Bulb holder and cord (and access to
an electrical outlet)
• 5 beakers
• Water
• White or light-colored sand
• Dark sand or dirt
51
Scope and Sequence
28.1 Weather
Learning Goals
• Explain the methods of heating and
cooling on a global scale.
• Explain the methods of heating and
cooling on a local scale.
• Interpret a daily newspaper weather
forecast.
Key question:
How does heating and cooling affect the
weather?
Leading questions:
• What causes local weather?
• What causes global weather?
• How does topography affect the weather?
• How does location affect the weather?
• What is the affect of humidity on the
weather?
Reading Synopsis
About half of the radiation from the sun to Earth is reflected back to space
and half is absorbed by the Earth’s surface. The atmosphere allows heat to
escape, but keeps enough in to keep the planet warm. Global warming, the
increase in Earth’s average temperature, is caused by increases in heattrapping gas (CO2) in the atmosphere from cars and industry.
Radiation hits the surface of the Earth at different angles. At the equator, the
sun is directly overhead. At the poles, the sun is low on the horizon. The
uneven heating of the Earth creates weather. When large masses of air collide,
the result is a weather front. The tilt of the Earth causes seasons. The northern
hemisphere tilts toward the sun during June and away from the sun in
January. The opposite is true for the southern hemisphere. The high specific
heat of water regulates the Earth’s temperature. Humidity is how much water
vapor is in the air. Precipitation is caused by the condensation of water vapor.
Materials and Setup
• The weather forecast pages from a
recent daily newspaper
Reading Synopsis
All everyday activities require energy. The cells in the human body harvest
chemical energy stored in food. Oxygen is required for this process.
The energy stored in foods, and the energy required to perform activities is
measured in units called calories. A calorie is the amount of heat required to
raise the temperature of 1 gram of water by 1 °C. Most food labels present
calories in units of 1000 called kilocalories or Calories.These values are
obtained using calorimetry. In this process, a known mass of water is heated
by burning a known amount of food.
Of the total amount of calories consumed by the human body, only 20 - 30%
are used to do work. The remainder are converted into heat. Metabolic rate is
the rate of energy consumption at all times within the body. When a body is
not using much energy, it can store the extra as glycogen and use this energy
at a later time.
Materials and Setup
• Empty soda can
• Empty steel can (i.e., a soup can,
about the same diameter size as the
soft-drink can) without the top lid.
• Thermometer
• Iron Bunsen burner grating
• Balance
• Large paper clip
• Small, very thin nail (for making
holes in the food)
• Marshmallows (and the package the
marshmallows came in with a food
label)
• Cashew nuts (and the package the
cashews came in with a food label)
• Potato chips and package
• Wooden matches (preferably, long
matches)
28.2 Living Systems
Learning Goals
• Analyze the energy content of common
foods.
• Compare the energy content of common
foods.
Key question:
Which types of food contain the greatest
amount of energy?
Leading questions:
• How is the chemical energy in food
converted into heat?
• How much energy does food contain?
• How quickly do you use the energy stored
in food?
• How does your body remove the excess
heat?
52
Scope and Sequence
28.3 Mechanical Systems
Learning Goals
• Describe how heat is generated in a
mechanical system
• Research how electricity is generated.
• Analyze the economic advantages and
disadvantages of various power sources.
Key question:
How much energy is lost as heat in a
mechanical system?
Leading questions:
• How is heat generated in mechanical
systems?
• How do you remove heat generated in
mechanical systems?
• How can you use heat to do mechanical
work?
Reading Synopsis
Mechanical systems contain moving parts that come in contact with each
other. These systems accomplish work with an initial input of energy. By
doing work, mechanical systems also generate heat. Most of this heat comes
from friction caused when contact is made between the parts of the system.
Deformation, the change of shape of an object, also produces heat in
mechanical systems. Finally, heat can be produced by air or fluid friction.
Lubricants and ball bearings reduce friction. Air cushions eliminate friction
between parts. The MAGLEV train and the game of air hockey work using
air cushions.
Friction can be useful, especially in the braking systems of bicycles and cars.
Heat can be harnessed, as in the steam engine, also called an external
combustion engine. By heating water, steam is produced to move a turbine
which keeps the engine going. Electric power plants use modern steam
engines. In internal combustion engines, such as in cars, combustion is inside
the engine.
Materials and Setup
• Thick rubber band
• Thermometer
• Soft-drink can
• Sand
Extension Activity:
• Access to the Internet or school
library.
53
Scope and Sequence
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54
Chapter Review Answer Keys
This section contains answer keys to chapter review questions for each chapter.
1 Review Answer Key ........................................................................................... 56
9 Review Answer Key .......................................................................................... 76
10 Review Answer Key ......................................................................................... 78
21 Review Answer Key ........................................................................................103
23 Review Answer Key ........................................................................................ 110
Answer Keys
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
Chapter
55
Chapter 1 Review
Chapter 1 Review Answer Key
Vocabulary review
Set One
Set Two
Set Three
Set Four
1. d
1. f
1. c
1. f
2. f
2. a
2. f
2. a
3. a
3. e
3. a
3. e
4. c
4. b
4. e
4. c
5. b
5. c
5. b
5. b
Concept review
1.
Different events take different amounts of time. Having different
units makes it easy to describe different events without using very
small or big numbers.
2.
Number; unit.
3.
An experiment is a situation set up to observe something. An
investigation is one or more experiments done to answer a question.
4.
True
5.
Asking a question; formulating a hypothesis; designing and
conducting an experiment; collecting and analyzing data; making a
tentative conclusion; testing conclusion; and refining original
question.
6.
Variable
7.
False
8.
True
9.
Speed is a measure of how quickly something gets from one place to
another.
56
10. Speed is how fast something is going, and velocity is how fast
something is going and its direction. The airplane’s speed was 500
miles per hour during most of my plane ride. The airplane’s velocity
changed during the plane ride: first it was 500 miles per hour south,
and then it was 500 miles per hour west.
11. Answers are:
a. t = d/v
b. v = d/t
c. d = vt
12. Its speed is 0 because the distance it travels is 0.
13. You measure the distance the object goes, and the time it takes to
travel that distance. You then divide the distance by the time.
Chapter 1 Review
Problems
1.
b
2.
There are 60 seconds in one minute and 30 minutes in half an hour.
60 sec/min × 30 min = 1,800 sec
3.
4.
Answers are:
a. 3
b. 1
c. 4
d. 2
Convert student’s height first to inches and then to meters.
(5 ft × 12 in/ft) + 2 in = 62 in
62 in × 1 m/39.37 in = 1.57 m
5.
30 cm × 1 in/2.54 cm = 11.8 in
6.
Convert all lengths to centimeters (another unit can be chosen).
a. a. 16 in × 2.54 cm/in = 40.6 cm
b. b. 26.6 cm
c. c. 1.1 ft × 12 in/ft × 2.54 cm/in = 33.5 cm
d. d. 0.4 m × 100 cm/m = 40 cm
The correct order from smallest to longest is b, c, d, a.
7.
8.
The experiment was not controlled because two variables were
changed at the same time—the activity the students did and what they
drank.
The question is: How does playing music affect plant growth?
The hypothesis is: Playing music helps plants grow better.
The procedure is: Place 10 plants in the same position on the window
sill in each room. Water both sets of plants the same way according to
plant instructions. Each afternoon, in one room only, play a local
classical station on the radio for two hours. (You should not be able to
hear the music in the other room.) Each morning measure the height
of each plant, its number of leaves, and any other observations about
plant health such as the appearance of the leaves. Record all the data.
Continue the experiment for 2 months (length of time depends on how
fast the plant grows). At the end of this period of time, evaluate your
results.
9.
Group 2 did the best experiment because their measurements of the
dependent variable were more precise. This probably occurred
because Group 2 did a better job of controlling the other variables of
the car and ramp experiment.
10. Answers are:
a. 1
b. 3
c. 2
11. Answers are:
a. 5 ft/min
b. 5 ft/min × 12 in/1 ft × 1 min/60 sec = 1 in/sec
c. 1 in/sec × 2.54 cm/in = 2.54 cm/sec
12. Answers are:
a. The average speed of the bumblebee is 89 cm/sec.
v = d ÷ t = 20 cm ÷ 0.2254 sec = 89 cm/sec
b. Yes. A greater amount of distance is traveled in the same amount
of time. Therefore, the bumblebee’s speed is greater.
13. v = d ÷ t = 35 cm ÷ 0.2061 sec = 170 cm/sec
14. The students might not have released the car in the same way each
time. They may have bumped the ramp slightly. The photogates could
have been moved slightly during the experiments.
57
Chapter 1 Review
Applying your knowledge
1.
You can count up to 156 using this method. Twelve marks on one
hand multiplied by 12 marks on the other hand equals 144 plus 12
more that can be counted and kept track of with the thumb.
2.
Contributions to numbering were made by many ancient
civilizations. Ancient groups your students might research include
the Babylonians, Egyptians, Greeks, Romans, Hindus, Arabs, and
Chinese.
3.
Answers will vary. Have students summarize the article and explain
how the scientific method was used. Students should try to figure out
the research question asked by the scientists and what their
hypothesis was. Have students describe at least one experiment
performed by the scientists and their results and conclusions. Finally,
students should try to identify what questions remain unanswered.
4.
Animal
Peregrine falcon
Cheetah
Pronghorn antelope
Lion
Quarter horse
Elk
Coyote
Gray fox
Ostrich
Hyena
Zebra
Greyhound
Whippet
Rabbit
(domestic)
Mule deer
Reindeer
5.
58
The speeds of animals in miles per hour. You may want to have your
students convert these speeds to another set of units.
speed in
mph
more
than 200
70
61
50
47
45
43
42
40
40
40
39.4
35.5
35
35
32
Animal
speed in
mph
Greyhound
39.33
Giraffe
Kangaroo
White-tailed deer
Grizzly bear
Human
Elephant
Black mamba snake
Wild turkey
Squirrel
Pig (domestic)
Chicken
Spider (Tegenearia atrica)
Giant tortoise
32
30
30
30
27.9
25
20
15
12
11
9
1.17
0.17
Three-toed sloth
Garden snail
0.15
0.03
Sports in which the speed of an individual is important include
running, swimming, cycling, speed skating, and drag racing.
Individuals also time themselves in flying or sailing long distances.
Encourage your students to find the most recent world records in
these sports.
Chapter 2 Review
Vocabulary review
Set One
Set Two
Set Three
1. e
1. e
1. c
2. a
2. d
2. b
3. f
3. a
3. d
4. b
4. f
5. d
5. c
Concept review
1.
2.
Two systems are shown; answers will vary.
4.
The position is determined by drawing a straight line from where a
person started to where he or she finished. However, the person
walking to her friend’s house had to go around a corner so the total
distance actually walked was greater.
5.
The position versus time graph. You can get the average speed from
the slope the graph, but you can also get the instantaneous speed at a
particular point in time from the graph.
6.
Speed
7.
Average speed is the total distance traveled divided by the total time
taken. Instantaneous speed is the speed at one point in time. If my
family travels to a city 80 miles away in 2 hours, then our average
speed for the trip was 40 miles per hour. During the trip, our car once
went 60 miles per hour, and at another time, we stopped to get gas and
our speed was 0. These two speeds are examples of instantaneous
speeds.
8.
Yes. When a car slows down, it eventually hits a speed of 0. Slowing
down is acceleration, so the 0 speed is the last point measured during
the time the car was slowing down.
Answers are:
Group A: vertical, y-axis, dependent variable.
Group B: horizontal, x-axis, independent variable.
3.
a, b
59
Chapter 2 Review
9.
The acceleration is 0.
10. Yes, because you are changing the direction you are traveling.
Change in direction and change in speed are both examples of
acceleration.
11. It gives instantaneous speed. The moment you speed up or slow
down, the speedometer changes.
12. Acceleration
Problems
1.
The scale is 1:10
2.
Answers are:
a.
b.
60
1 and 3
3.
Graph:
4.
Graph:
Chapter 2 Review
5.
Acceleration is change in speed divided by change in time.
acceleration= (100 cm/sec) ÷ 0.5 sec = 200 cm/sec2
6.
The dependent variable is the distance you can travel. The
independent variable is the amount of gas in the car.
Graph:
7.
Graph and answers are:
All the data points after 20 cm are suspect because the car’s speed
should be increasing in gradually smaller amounts at each 10 cm
measurement. This data doesn’t show that pattern.
Note: Be sure that students understand that this is not a speed vs. time
graph. The curve of a speed vs. distance graph is not related to
acceleration.
8.
140 cm/sec, 180 cm/sec, 240 cm/sec, 280 cm/sec
9. a) 2 b) 1 c) 4 d) 3
10. 1 hour and 36 minutes
11. 162,000 cm or 1.62 km
12. 1) E 2) B 3) D
13. speed = change in position/ change in time = 2/4 = 0.5 m/sec
1.
Answers will vary. A world record for the 100 meter race in track and
field is 9.79 seconds.This is 10.2 meters/second, or 59 miles per hour.
Cheetahs can run as fast as 70 miles per hour. They can accelerate
from zero to this speed in seconds. Diving speeds of the gyrfalcon
have been measured at 208 kilometers per hour (130 miles per hour).
2.
You can measure the speed of nail growth by marking a point on the
base of several nails and then measuring each morning (at the same
time) how far the spot has moved from the base. Your measurements
could be recorded in millimeters per day.
61
Chapter 3 Review
Vocabulary review.
Set One
Set Two
Set Three
Set Four
1. e
1. b
1. b
1. d
2. c
2. f
2. f
2. a
3. a
3. d
3. d
3. b
4. b
4. c
4. e
4. c
5. f
5. a
5. c
5. f
Concept review
1.
2.
A force is an action that has the ability to change motion. Forces can
be applied by engines or tensed muscles. Weight is the force of
gravity on an object.
If I jump forward on a newly waxed floor with my socks on, I will
slide along the floor without stopping until friction or another object
stops me. (Examples will vary.)
10. The mass of the two objects and the distance between them.
11. Answers are:
a. Newton or pound
b. Kilogram
c. Newton or pound
12. Answers are:
a. Gravity and friction
b. Gravity
c. Friction
3.
The 10-kilogram ball.
4.
Start; stop
5.
When I jump, the force of my muscles causes me to at first accelerate
upwards; then the force of gravity takes over and I deaccelerate, stop
in midair, and then accelerate downwards. (Examples will vary.)
6.
The amount of force that causes an acceleration of 1 meter/second2
for a body with a mass of 1 kilogram.
7.
Gravity
14. Answers are:
a. Pairs
b. Amount
c. Direction
8.
c
15. Mass and velocity
9.
Mass is a constant, fundamental property of an object. Weight is
force caused by gravity; it varies throughout the universe.
16. If a bowling ball hits a pin, the ball slows down, but the pin rolls.
(Examples will vary.)
62
13. If I am on roller blades, I can push against a wall, and the wall
pushes back on me and I start rolling. (Examples will vary.)
Chapter 3 Review
Problems
1.
F = m × a = 10 kg × 0.1 m/sec2 = 1 N
2.
Answers are:
a. On the surface of the Earth, weight is 4.4 kg × 9.8 N/kg = 43.12
N
b. On the surface of the Earth, weight is 4.4 kg × 2.2 lb/kg = 9.68 lb
3.
Answers are:
a. 9.8 m/sec
b. 19.6 m/sec
4.
The table is pushing up on the block of lead with a force of
500 newtons.
5.
The 110-pound person would weigh 311 N or 70 pounds on Jupiter.
This is more than what the person would weigh on Io. This makes
sense because although Io’s diameter is smaller than Jupiter’s
diameter, it also has less mass.
6.
Answers are:
a. I push the cart, and the cart pushes back on me. These forces are
equal. The frictional force of my feet on the ground opposes the
push of the cart, and I don’t move. Because the cart has wheels,
the frictional force opposing my push on the cart is less, and my
push overcomes it. The cart moves away from me.
b. Me
7.
P = m × v = 0.5 kg × 4 m/sec = 2 kg-m/sec
8.
Answers are:
a. Pinitial = m × vinitial = 60 kg × 5 m/sec = 300 kg-m/sec
b. Pfinal = m × vfinal = 60 kg × 2 m/sec = 120 kg-m/sec
c. Change in P = Pfinal - Pinitial
Change in P = 120 kg-m/sec - 300 = -180 kg-m/sec
1.
One way is to decrease friction between two surfaces is using a
lubricant. Some lubricants are oil, grease, and water. You can reduce
the pressure between the sliding surfaces. Instead of sliding a heavy
crate along the floor, you can lift up on it as it is moved. Using very
smooth surfaces such as ball bearings can also reduce friction.
3.
In space, some muscles get weaker, and bones lose calcium. Balance
and sleep are affected. Fluid in the body goes to different places than
normal. Astronauts have to exercise to reduce the muscle and bone
loss. As astronauts spend more time in space, more is learned about
the effects of space on the human body.
2.
Joints in the human body contain a lubricating fluid called synovial
fluid. Like oil in an engine, this fluid reduces friction between the
moving solid parts of the joint. This fluid has very unique properties
because it acts like a liquid when the joint is moving slowly but like
an elastic solid when the joint is moving quickly.
4.
The movement of the skates along solid ice is opposed by the force of
sliding friction. When some ice melts, there is water between the
skate and the ice; now it is viscous friction that opposes motion.
Viscous friction opposes motion less than sliding friction does.
63
Chapter 4 Review
Vocabulary review
Set One
Set Two
Set Three
1. d
1. b
1. e
2. b
2. d
2. f
3. f
3. e
3. a
4. a
4. c
4. c
5. d
5. c
Concept review
1.
A car is a good example of a mechanical system because more than
one system is involved in its operation. For example, a car runs using
an ignition system, a cooling system, an air intake system, a starting
system, a fuel system, and an exhaust system. Additionally, within
these systems, machines are combined. The air intake system uses a
turbine and a compressor. The cooling system uses a water pump and
a fan. The fuel system uses a carburetor to mix gas and air. The
engine of the car is an internal combustion engine that uses pistons
and a crank shaft.
2.
When a machine can use a smaller input force to produce a greater
output force, it multiplies forces.
3.
In the scientific method you ask a question to find out how
something works. You answer the question by designing and
conducting a controlled experiment. In the engineering cycle, you
solve a problem that exists. You do this by creating or improving
inventions.
64
4.
One feature on the current toothbrush design (like brush height) can
be improved for better function of the toothbrush. First, I create new
toothbrush design with the feature improved. Then, I build a
prototype of the new design and test it to see if it works. I evaluate
the test and use it to begin the cycle over again by creating an
improved or different design. I repeat the cycle until I am satisfied
the new toothbrush works the way I want it to work.
5.
Answers will vary. A sample answer is: There is a garage in the
basement of our apartment building and water runs into the garage
during a rain storm. Is there something that can be placed by the
garage door that prevents water from coming in but wouldn’t
interfere with the door opening or cars driving in and out?
6.
Answers will vary. One example is the flexible toothbrush that can
reach more places in your mouth.
7.
If the fulcrum is placed under the lever with one arm on each side of
the fulcrum, the input arm must be shorter than the output arm.
Chapter 4 Review
8.
If two children of equal weight are sitting on the seesaw (the seats are
both the same distance from the fulcrum) it is in equilibrium. If two
children of unequal weight are sitting on the seesaw the bigger child
has more force and that side of the seesaw goes down.
10. a
11. b
12. d
13. The longer the input arm is in relation to the output arm, the more
output force there is in relation to input force. Specifically, input force
times the distance of the input arm equals output force times the
distance of the output arm.
14. A machine with a mechanical advantage greater than is more useful.
It allows me to lift more wight than I could without a machine.
9.
It is a device that has an input force and an output force and
accomplishes work with one movement.
15. The 12, 24, and 36 teeth gears give combinations of 2:1, 1:2, 3:1, 1:3,
3:2, and 2:3. You can make a 12:1 gear ratio by using the following
combinations: a 2:1 followed by a 2:1 followed by a 3:1 combination.
Problems
1.
Answers are:
a. When multiplied together, they equal the output force.
b. The number of supporting strings is the independent variable,
and input force is the dependent variable.
2.
Answers are:
a. 100 N
b. 50 N
c. 20 N
d. 10 N
3.
Answers are:
Input Force
10 N
30 N
500 N
625 N
c.
Output Force
100 N
30 N
1,350 N
200 N
Mechanical
Advantage
10
1
2.7
0.32
Answers are (number of strings, mechanical advantage):
2, 2; 4, 4; 6, 6; 1, 1; 3, 3; 5, 5
65
Chapter 4 Review
4.
The last example has a mechanical advantage of 0.32. This means
that I have to apply a force three times the weight of what I was
lifting! A machine with a mechanical advantage greater than 1 is
more useful for lifting 200-newton objects.
5.
No. Since it is a ratio, the units cancel.
6.
Mechanical advantage
= output force ÷ input force = 200 N ÷ 20 N = 10
7.
No. The input arm has to be longer than the output arm in order for
the lever to have a mechanical advantage that is greater than 1.
8.
The ratio of the weight of the box to Betsy’s weight is about 3. If the
output arm is 2 feet long and the input arm is 6 feet long, Betsy can
lift the box.
5.
Mechanical advantage = output force ÷ input force.
Output force of the jaw = mechanical advantage of the jaw × input
force = 0.7 × 800 N = 560 N
Output force of the biceps = mechanical advantage of the biceps ×
input force = 0.14 × 800 N = 112 N
The output force of the jaw is larger.
6.
Input force of the jaw = output force ÷ mechanical advantage of the
jaw = 500 N ÷ 0.7 = 714 N
Input force of the biceps = output force ÷ mechanical advantage of
the biceps = 500 N ÷ 0.14 = 3,571 N
The biceps muscles have to provide much more force than the jaw
muscle to achieve the same output. This is why the biceps muscle is
much larger than a jaw muscle.
1.
It is possible to lift a very heavy object higher by pushing it or
pulling it up a ramp. Because the ramp adds distance, you use less
force in lifting the object when compared to lifting straight up.
2.
Output force = mechanical advantage × input force = 3.5 × 65 N =
227.5 N
3.
Input force = output force ÷ mechanical advantage = 500 N ÷ 5 =
100 N
4.
Input force times the distance of the input arm equals output force
times the distance of the output arm. Rearrange the terms of this
equation to describe mechanical advantage in terms of lever arm
lengths.
Mechanical advantage of the jaw = distance of the input arm ÷
distance of the output arm = 7 cm ÷ 10 cm = 0.7
Mechanical advantage of the biceps = distance of the input arm ÷
distance of the output arm = 5 cm ÷ 35 cm = 0.14
The mechanical advantage of the jaw is larger.
66
Chapter 5 Review
Vocabulary review
Set One
Set Two
1. a
1. e
2. c
2. d
3. d
3. b
4. b
4. c
5. f
Concept review
1.
The energy used to apply the input force over a distance is equal to the
energy of the output force over a distance (plus energy lost to
friction).
2.
Work is accomplished when something is moved somewhere. Energy
is the ability to do work.
3.
You explain that you pull the input force of 20 newtons five times as
far as the distance you lift the 100 newtons. You explain that distance
times force is equal to work. Energy is the ability to do work. You
expend 20 × 5 = 100 newton-meters, which is equal to 100 joules of
energy, to lift the 100-newton weight one meter. The output work is
equal to 100 newtons × 1 meter, or 100 newton-meters, or 100 joules.
Therefore, the energy input is equal to the energy output and the law
of conservation of energy is fulfilled. You also explain that, in order to
increase output force relative to input force, input distance must be
increased.
4.
Some energy might be lost as heat or wearing away of material
because of friction.
5.
Answers are:
Kinetic energy: a, c, d, b, e
Potential energy: e, b, d, c, a
67
Chapter 5 Review
Problems
1.
Answers are:
a. 60 J
b. 9 J
c. 4,000 J
d. 138 J
2.
56 J
3.
Answers are:
a. W
b. W
c. NW
d. W
e. NW
4.
Work = force × distance.
In the first task, work = 15 N × 3 m = 45 J.
In the second task, work = 7 N × 10 m = 70 J.
The second task requires more work.
5.
Distance = work ÷ force = 30 J ÷ 15 N = 2 m
6.
Potential energy = mass × g (acceleration due to gravity) × height
Mass = potential energy ÷ (g × h)
Mass of bicycle + mass of Ken = potential energy ÷ (g x h)
Mass of bicycle = [potential energy ÷ (g x h)] - (mass of Ken)
Mass of bicycle = [1,000,000 J ÷ (9.8 m/sec2 x 1,600 m)] - 54 kg
Mass of bicycle = (1,000,000 J ÷ 15,680 m2/sec2) - 54 kg
Mass of bicycle = 63.8 kg - 54 kg = 9.8 kg
7.
2 m of rope
8.
Efficiency = (work output ÷ work input) × 100
= (45 J ÷ 48 J) × 100 = 94%
9.
Power = work ÷ time.
In the first machine, power = 280 J ÷ 40 sec = 7 W. In the second
machine, power = 420 J ÷ 120 sec = 3.5 W.
The first machine is twice as powerful as the second machine.
68
10. Answers are:
a. Twice as big.
b. Twice as fast.
11. Answers are:
a. Work = force × distance = 35 N × 350 m = 12,250 J
b. Power = work ÷ time = 12,250 J ÷ 6 sec = 2,042 W
12. Power = work ÷ time = 55 J ÷ 55 sec = 1 W
13. Efficiency = (work output ÷ work input) × 100
Work output = (efficiency ÷ 100) × work input
Work output = (86 ÷ 100) × 70 J = 60 J
14. Efficiency = (work output ÷ work input) × 100
Work input = (work output ÷ efficiency) × 100
Work input = (150 J ÷ 72) × 100 = 208 J
Chapter 5 Review
1.
Answers are:
a. Efficiency = (work output ÷ work input) × 100
Work input = (work output ÷ efficiency) × 100
Work input = (25 mpg ÷ 15) × 100 = 167 mpg
b. Some of the energy is converted to heat, some is lost as friction
between all the surfaces of the car, and some is lost as friction
between the tires and the road.
2.
A perpetual motion machine is a machine without frictional forces.
This is not possible because, in any machine, there is always some
energy lost to friction.
3.
A watt is a unit of power. Light bulbs vary in their number of watts.
Most range from 5 W to 150 W. For each watt, a light bulb uses 1
joule of energy per second.
4.
Answers will vary depending on the number of light bulbs in the
school and the power of these light bulbs.
5.
The chart should include the following energy transformations. Corn
flakes (chemical potential energy) is converted to kinetic energy in the
movement of muscles which is converted to kinetic energy of the
movement of the bicycle. The kinetic energy of the bicycle is
converted to the electrical energy of the generator. The electrical
energy of the generator is converted to light (and heat) when the bulb
is on.
69
Chapter 6 Review
Vocabulary review
Set One
Set Two
1. d
1. c
2. f
2. f
3. c
3. b
4. e
4. d
5. a
5. a
Concept review
1.
Circuits and water pipes provide pathways for flow. Circuits and
water pipes bring useful things into our homes.
7.
A charged object has more of one kind of charge. A neutral object
has equal amounts of positive and negative charge.
2.
Some examples are house wiring, nerves, lightning, and car wiring.
8.
Like charges repel each other, and unlike charges attract each other.
3.
The switch breaks the circuit path.
9.
4.
It is easier to draw and understand a circuit if standard symbols and
diagrams are used.
Each hair becomes charged. Since the charge on each hair is the
same, each charged hair repels other charged hairs.
5.
The scar tissue that forms when there is a cut prevents the electrical
connection from reforming.The original nerve can’t fully heal.
6.
Negative charge is on the electron, and positive charge is on the
proton.
Problems
1.
a, b and d (Being able to answer this question and the next is
contingent upon students completing Investigation 6.1.)
2.
To close circuit c, move the wire so that it is connected to the light
bulb in the same way as circuit b.
70
10. Charges in a cloud are separated, and negative charges build up on
the bottom of the cloud. These negative charges repel negative
charges in the ground, and the ground becomes positively charged.
When there is enough buildup of charge, the negative charges in the
cloud flow to the ground, heating the air so much that it glows.
11. Versorium
Chapter 6 Review
3.
4.
Circuit diagram:
5.
Because the lightning rod has more charges, it attracts lighting more
strongly. It must have charge opposite to the charge of lighting.
6.
The balloon sticks. The negative charge on the balloon is attracted by
the area of positive charge on the wall.
3.
Benjamin Franklin studied electricity. In fact, he was one of the first
individuals to perform experiments with electricity. He is known for
flying a kite with a key during a storm to see if the key would conduct
electricity from the lightning (which Franklin suspected was an
electric current). Benjamin Franklin is credited with coining many
terms related to electricity: battery, electrician, and charge, for
example. He also invented the lightning rod.
4.
Answers will vary. Two items of clothes of the same kind of fabric
will not stick together; however, two items of different fabrics will.
For example, a cotton sock will stick to a nylon pair of shorts. In the
drying process, some kinds of fabrics lose charge and some gain
charge. Static cling occurs between fabrics that have opposite charges.
Some charge must leave the one piece of tape and then move to the
other piece of tape. The pieces of tape are now charged with opposite
kinds of charge.
1.
2.
Students may have had experiences in which the electricity in their
house was not working or during an electrical brown out. In addition
to not having light, not having electricity means that all appliances
(the refrigerator, oven, toaster, hair dryers, air conditioners, and
furnaces) do not work. Additionally, items used for work and
entertainment, like computers and television sets, do not work either.
Have your students think about how they might change their habits
without these things. What would they miss having the most in the
event of an electrical power outage?
Common appliances come with circuit diagrams. Refer students to
Section 6.1 What is a Circuit? in the Student Edition for common
symbols that are used in circuit diagrams.
71
Chapter 7 Review
Vocabulary review
Set One
Set Two
Set Three
1. d
1. d
1. e
2. e
2. e
2. c
3. f
3. a
3. b
4. a
4. b
4. d
5. c
5. c
Concept review
1.
2.
A battery creates potential energy by using the chemical energy of
reactions to separate positive and negative charge. This separation is
like lifting a marble above the ground. The work done when the
charges separate is stored as potential energy, just like the work done
in lifting the marble against the force of gravity is stored in the
marble as potential energy.
The pump uses energy from electricity to raise the water higher. This
process gives the water potential energy. The battery uses energy of
chemical reactions to separate charges. This process gives the
charges potential energy.
3.
Their voltage is the same, but the D battery has more chemicals, so it
can provide more energy over time and therefore will last longer.
4.
Both measurements are rates and are made at a specific point. In a
circuit, you could measure how many coulombs of charge move past
a point in one second. In a water system, you could measure how
many gallons of water move past a point in one minute.
5.
A circuit breaker uses metal that expands with heat. When the
current gets too high, the expanded metal breaks the circuit.
72
6.
Alternating
7.
Direct
8.
The main purpose of a ground fault circuit interrupter is to protect a
person from current that is leaking from an electrical device. It
breaks a circuit if it senses a difference in current flowing into and
out of the device.
9.
The copper conducts current to where it should go, and the plastic
insulates the circuit, preventing the current from going somewhere it
shouldn’t go.
10. Possible answers are:
a. Copper
b. Glass
c. Carbon
11.
Answers are:
a. It needs more resistance so it can get hot enough to glow.
b. It doesn’t melt at high temperatures.
Chapter 7 Review
Problems
1.
Two batteries are about equal to 3 volts. Therefore, one coulomb of
charge has 3 joules of energy.
2.
5.
Voltage is a measurement of the energy per unit charge. It has to be
measured in reference to another point, just as height is measured in
reference to another point.
The meter reads 0.5 A. Current is the same at all points. (Being able to
answer this question is contingent upon students completing
Investigation 7.2.)
6.
The current must flow through the meter so it can be measured.
7.
Clip leads, light bulbs, pencil lead, air
3.
The measured voltage is close to negative 1.5 volts.
8.
Copper
4.
Amps equals coulombs per second. The problem states that 650
coulombs of charge pass through the circuit in 1 minute. One minute
equals 60 seconds.
650 C ÷ 60 sec = 12.5 A
9.
Since the circuit also has current through it, you must turn the circuit
off so that the meter only measures the current through the object.
1.
Have students write a short essay describing the work they
accomplished and what they learned.
2.
Some neurological disorders that students might research include
epilepsy, aphasia, multiple sclerosis, muscular dystropy, or
Parkinson’s disease.
3.
Have students write a short essay describing the work they
accomplished and what they learned.
73
Chapter 8 Review
Vocabulary review
Set One
Set Two
1. e
1. f
2. a
2. c
3. f
3. e
4. c
4. d
5. d
5. b
Concept review
1.
The current goes up.
2.
The current goes down.
3.
Aluminum has a lower conductivity than copper and therefore, more
resistance. The aluminum may get hotter than the original copper
wire and start a fire.
4.
If the amount of current going through the extension cord is greater
than it can safely carry, the extension cord can get hot enough to start
a fire.
5.
Power is the amount of work done per unit of time. It can also be
stated as the amount of energy converted from one form to another
per unit of time.
6.
When the fan runs, electrical energy changes to kinetic energy. Some
is also converted to heat—you can feel the motor warm up.
7.
Watts
8.
Sample answers: Microwave, 1.35 kW; toaster, 1.55 kW; light bulb,
60 W
9.
Watts equals joules per second
10. Energy (or work)
Problems
1.
R=V÷I
R = 120 V ÷ 10 A
R = 12.0 Ω
74
2.
V=I×R
V = 2.0 A × 4.5 Ω
V=9V
Chapter 8 Review
3.
One alkaline battery has a voltage of about 1.5 volts.
I=V÷R
I = (2 × 1.5 V) ÷ 6 Ω
I = 0.5 A
4.
R=V÷I
R = 120 V ÷ 15 A
R = 8.0 Ω
5.
2.5
6.
900 W = 0.9 kW; 15 min.= 0.25 h
0.9 kW × 0.25 h = 0.23 kWh
7.
P=V×I
P = 120 V × 6 A
P = 720 W
8.
Answers are:
a. Iron: 1.2 kW × 3.5 h = 4.2 kWh
Lamp: 0.1 kW × 125 h = 12.5 kWh
Coffee maker: 0.7 kW × 15 h = 10.5 kWh
b. Iron: 4.2 kWh × $0.15/kWh = $0.63
Lamp: 12.5 kWh × $0.15/kWh = $1.88
Coffee maker: 10.5 kWh × $0.15/kWh = $1.58
1.
Have students write a short essay describing what they learned and
how their family plans to save electricity. This project requires that
students complete a follow up assignment. The follow up assignment
could be another essay or a presentation that describes how well the
student’s family made changes to save electricity, and whether or not
money was saved as a result.
2.
Have students write a report describing their findings. If students find
situations in which the current rating for the appliance exceeds that of
the extension cord, have them explain how they fixed the problem.
3.
Students can find out this information by calling or visiting the web
site of their electrical company. For example, one electric company
worked together with a light bulb supplier to offer energy saving light
bulbs at a discount to the customers of the electric company. Discuss
why energy-saving programs benefit both the consumer and the
electric company.
4.
Superconductivity is a property of certain solid materials that lack
electrical resistance once they are cooled to a very low temperature.
The temperature is usually below - 253°C. Superconductors can be
used for motors, generators, transformers, computer parts, sensitive
magnetic measuring devices, and magnetic energy-storing systems.
75
Chapter 9 Review
Vocabulary Review
Set One
1. b
2. c
3. a
4. f
5. e
Concept review
1.
You will be able to turn each device on and off without affecting
others; the energy available to each device is the same at all times.
6.
It states that energy that leaves the circuit (in the form of light, heat,
motion, etc.) equals energy supplied to the circuit by the battery.
2.
You have to plug something into each outlet and have it on all the
time or connect the outlets together with a wire.
7.
The charges collide with the tungsten atoms and transfer their
potential energy to them. The energy becomes heat, and then light.
3.
Series
8.
The total current increases.
4.
Yes
9.
Total voltage across the battery
5.
The total resistance increases.
10. One half the resistance in each branch
11.
a. parallel circuit; b. short circuit; c. series circuit
Problems
1.
Answers are:
a. The battery supplies 4.5 V (3 × 1.5 V). The voltage drop across
each bulb is 2.25 volts (4.5 V divided across two similar bulbs).
b. I used Kirchhoff’s voltage law.
3.
Answers are:
a. Total R = 5 Ω + 1 Ω + 1 Ω = 7 Ω
b. Total V = 1.5 V + 1.5 V + 1.5 V + 1.5 V = 6 V
I = V ÷ R = 6 V ÷ 7 Ω = 0.86 A
2.
Total R = 1 Ω + 1 Ω + 1 Ω = 3 Ω
V = I × R = 1.5 A × 3 Ω = 4.5 V
4.
Total voltage = 1.5 V + 1.5 V + 1.5 V + 1.5 V = 6 V
R (total resistance) = V ÷ I = 6 V ÷ 0.857 A = 7 Ω
They used one 5-ohm resistor and two 1-ohm resistors.
76
Chapter 9 Review
5.
Answers are:
a. They should use the 1-ohm resistor.
I = V ÷ R = (1.5 V + 1.5 V) ÷ 1 Ω = 3 A
b. R = V ÷ I = (1.5 V + 1.5 V) ÷ 1 A = 3 Ω
They should use three 1-ohm resistors.
6.
c
7.
a and c
8.
Answers are:
a. Branch 1: I = V ÷ R = 9 V ÷ 1 Ω = 9 A
Branch 2: I = V ÷ R = 9 V ÷ 2 Ω = 4.5 A
Branch 3: I = V ÷ R = 9 V ÷ 3Ω = 3 A
b. Total current = 9 A + 4.5 A + 3 A= 16.5 A
c. R = V ÷ I = 9 V ÷ 16.5 A = 0.55 Ω
d. The total current would increase.
9.
Answers are:
a. I = (3 V ÷ 3 Ω) + (3 V ÷ 1 Ω) = 1 Α + 3 Α = 4 A
b. The 1-ohm bulb uses more current.
10. b
11. d
Applying Your Knowledge
1.
Circuit diagram:
2.
Circuit diagram:
77
Chapter 10 Review
Vocabulary review
Set One
Set Two
Set Three
1. b
1. f
1. f
2. d
2. e
2. d
3. e
3. c
3. a
4. f
4. a
4. e
5. a
5. d
5. c
Concept review
1.
Lodestone and magnetite
7.
The core makes the electromagnet stronger.
2.
The compass
8.
3.
The names of the poles describe which way that part of the magnet
points when suspended in air.
An electromagnet is used in a doorbell to ring the bell. An
electromagnet is used in a generator to generate electricity.
9.
The north pole of a magnet is attracted to the south pole of a large
magnet inside the earth, which is close to the geographic north pole.
Each electron in an atom is like a tiny electromagnet. In a magnet,
the electrons line up so that their magnetic fields add together.
10. Using the right hand rule, picture A is correct.
5.
Like poles repel each other, and unlike poles attract each other.
11. b, c, and d
6.
You can increase the amount of electric current in the wire, increase
the amount of iron or steel in the electromagnet’s core, and increase
the number of turns in the coil.
12. b and c
4.
Problems
1.
Answer is:
78
2.
Answers are:
a. About 33 millimeters.
b. He could move the magnet. The non-magnetic table doesn’t
affect magnetic attraction. The force of the magnet is felt at 33
millimeters and the thickness of the table, 25 millimeters, is
less.
Chapter 10 Review
3.
The atoms in the steel paperclip line up so that there is a strong
magnetic field.
4.
Answer is:
5.
Answer is:
6.
Answer is:
7.
Electric charge
8.
a, b, and d
9.
P = V × I = 1.5 V × 1 A = 1.5 W
10. The commutator switches the poles of the electromagnets as the
correct time to keep the armature of the motor turning.
1.
Have students write a short paragraph about their technique for
suspending the magnet in midair.
3.
The movement of the wheel turns a magnet inside a coil of wire. This
movement generates electricity which turns the light on.
2.
A speaker contains a permanent magnet next to an electromagnet. An
electric current created from sound goes through the electromagnet.
This current changes, and the strength of the electromagnet varies in
response. It moves close or further from the permanent magnet
depending on the level of current. This movement is used to recreate
the original sound by causing a paper cone to vibrate. Cassette tapes
contain an iron oxide coating. In a recording microphone, an
electromagnet moves in response to sound. This electromagnet passes
near the tape and parts of the coating get magnetized. When played
back, the magnetized areas produce a varying electric current.
4.
This car would not work. The motor uses energy to push the propeller.
The propeller cannot generate more energy than was used to power it,
and in fact, must generate less due to energy losses in the system.
79
Chapter 11 Review
Vocabulary review
Set One
Set Two
1. c
1. d
2. d
2. a
3. e
3. b
4. a
4. e
5. b
5. c
Concept review
1.
Examples include Earth, clocks, and sound speakers.
7.
b
2.
They are inversely related.
8.
b and d
3.
b, c, and d
9.
b
4.
a
10. b
5.
b
11. b
6.
a, d, and e
12. a
Problems
1.
c
2.
40 cycles
3.
T = 1/f = 1/(30 times/sec) = 1 sec/30 times = 0.033 sec
4.
Answers are:
a. 1 sec
b. 1 cm
c. 5 cycles
80
5.
Group 1: pendulum A
Group 2: pendulum C
Group 3: pendulum B
Group 4: pendulum D
6.
Graph B
7.
Graph C
8.
Graph A
Chapter 11 Review
1.
24 hours
2.
F = number of cycles/sec = 240 beats/120 sec= 2 Hz
3.
Earth orbits around the sun. The period of this cycle is 1 year. The
moon orbits around Earth. The period of this cycle is about 1 month.
4.
Answers are:
a. The frequency of spokes passing the sensor is 36 Hz.
b. The wheel turns 60 times in one minute.
5.
My heart beats 84 times a minute. In a day, my heart beats 120,960
times (84 times/min × 60 min/hr × 24 hr/day).
6.
The period of the vibration in the engine is 0.5 seconds. This vibration
corresponds to part B, which also has a period of 0.5 seconds (the
inverse of its frequency of 2 turns/second). Part B may fail.
81
Chapter 12 Review
Vocabulary review
Set One
Set Two
Set Three
Set Four
1. c
1. e
1. b
1. b
2. e
2. c
2. c
2. d
3. a
3. d
3. d
3. a
4. b
4. b
4. a
4. c
5. d
5. a
Concept review
1.
b
4.
a
2.
b (sound waves and information transmission), c (a vibration that
moves through the ground), e (sound waves), f (X rays), and g (light
waves). Answer choices a and d may also b included if the student
explains that these vehicles can’t operate without making noise, and
sound is a wave.
5.
a
6.
b
7.
b
8.
c
5.
a
6.
b
7.
Harmonic 1: frequency = 11 Hz, wavelength = 2 m
Harmonic 3: frequency = 33 Hz, wavelength = 0.67 m
3.
b and d
Problems
1.
Answers are:
a. T = 1/f = 1/(40 cycles/sec) = 0.025 sec
b. 60 Hz (three times the fundamental frequency)
c. 160 Hz (eight times the fundamental frequency)
d. 2 antinodes
2.
The third pattern isn’t correct. According to the data from the other
patterns, the third pattern should have a frequency of 36 Hz.
3.
c
4.
5 m/sec
82
Chapter 12 Review
1.
68 cm × 120 Hz = x × 180 Hz
x = 68 cm × 120 Hz / 180 Hz = 45.3 cm
You need a string that is 45.3 centimeters long.
2.
If the frequency of the marchers matches the natural frequency of the
bridge, the marchers could cause the bridge to vibrate very strongly,
which might damage or break the bridge.
3.
If two waves travel in opposite directions and hit each other, they
could form a wave that is twice as big as either one. This large wave
could wreck a ship as it goes up, over, and down the huge wave.
4.
If the natural frequency of the building is the same as that of the
earthquake, the building vibrates a great deal and probably is
damaged. Changing the height or changing the building materials are
two possible ways to alter the natural frequency of a building.
83
Chapter 13 Review
Vocabulary review
Set One
Set Two
Set Three
Set Four
1. c
1. e
1. d
1. e
2. a
2. a
2. c
2. f
3. d
3. b
3. a
3. b
4. f
4. c
4. b
4. c
5. b
5. d
5. f
5. a
Concept review
1.
a
10. True
2.
a, c, and d
11. b and c
3.
a, b, and c
12. Answers are:
4.
a
5.
a, b, and c
6.
c
13. a
7.
False
14. b and c
8.
True
9.
False
84
steel
Fastest
wood
water
helium
air
Slowest
Chapter 13 Review
Problems
1.
b
2.
b
3.
a
4.
The sound travels back and forth for a total of 340 m (2 × 170 m). It
takes one second for the echo to return.
5.
a
3.
Judging from the sonogram of the three voices in the reading, the
range of frequencies needed in a phone speaker is 100 Hz to 2,000 Hz.
Because voices have some frequencies outside this range, voices on
the telephone don’t always sound like the real person.
1.
Make all three sides of the speaker box a different length, and make
each length a prime number. Since prime numbers don’t have factors,
one side can never be a factor of another side and cause extra
resonance.
2.
The steel of the railroad track carries sound 18 times faster than
air.The engineers would have 18 times as much advance notice that a
train was coming than they would have had by listening through the
air alone.
85
Chapter 14 Review
Vocabulary review
Set One
Set Two
Set Three
Set Four
1. b
1. c
1. d
1. b
2. e
2. a
2. a
2. e
3. a
3. e
3. e
3. a
4. c
4. d
4. c
4. d
5. d
5. b
5. b
5. c
Concept review
1.
Photoluminescence means light energy can cause other atoms to emit
light.
6.
a
7.
b
2.
Incandescence happens when heat energy causes electrons to change
orbits and give off light.
8.
c
3.
c
9.
b
4.
a
5.
a and b
10. a
11. c
Problems
1.
In order from fastest to slowest: b, a, c.
7.
magenta, cyan, yellow, and black
2.
white
8.
red, green, and blue
3.
red and green
9.
a
4.
b
5.
b
6.
It is absorbed and turned into heat.
10. The wavelength and frequency of green light are approximately 580
nm and 517 tHz, respectively. Plants do not absorb much of the light
in this range. Instead, they reflect it. Because they don’t absorb this
wavelength of light, they can’t use its energy for photosynthesis.
86
Chapter 14 Review
11. Radio waves, microwaves, infrared waves, visible light, ultraviolet
rays, X rays, gamma rays.
12. Find the number of kilowatts of power that each light bulb uses.
Incandescent: 100 W × 1 kW/1,000 W = 0.1kW
Fluorescent: 23 W × 1 kW/1,000 W = 0.023 kW
Find the number of hours both bulbs are on per year:
24 hrs/day × 365 days/year = 8,760 hrs
Find the kilowatt hours used by each bulb per year:
Incandescent: 0.10 kW × 8,760 hrs = 876 kWh
Fluorescent: 0.023 kW × 8,760 hrs = 201.5 kWh
Find the cost of using each bulb for one year:
Incandescent: 876 kWh × $0.10/kWh = $87.60
Fluorescent: 201.5 kWh × $0.10/kWh = $20.15
Calculate how much money you would save by switching:
$87.60 (incandescent bulb) - $20.15 (fluorescent bulb) = $67.45
1.
Energy produced by the fire causes electrons to change orbits and
emit light.
2.
The water eliminates the heat and the source of energy for the fire.
3.
There are three kinds of photochemical receptors in the eyes. The
receptors respond to red, blue, and green. The signals are sent to the
brain.
4.
Not all color sensors are present in people with color blindness.
5.
Sample answers: Dogs and cats have no color sensors. Honeybees
have three different sensors.
6.
Project responses will vary. Have students write up their research in a
short paper.
7.
Project responses will vary. Have students make a prototype of one
improved product they designed. Students could also make
informational brochures to raise awareness about color blindness.
87
Chapter 14 Review
8.
Project answers will vary.
9.
Computers give off light. Paint absorbs light. To get red, green, and
blue from a computer screen you just turn on appropriate colored
pixels. To get red paint, you add magenta and yellow. To get green
paint, you add cyan and yellow. To get blue paint, you add cyan and
magenta.
10. The answers are:
a. The range of values for color on a computer screen is 0 to 255.
b. RGB: R = 255, G = 153, B = 0
CMYK: C = 3, M = 40, Y = 94, K = 0
c. 1000 pixels × 3 numbers/pixel × 8 bits/number = 24,000 bits of
memory, or 24K
11. The cloudiness of ice cubes can be due to trapped air bubbles and
impurities in the water. Clear ice cubes can be formed by first boiling
distilled water to remove air from the water. Another way to prevent
air from getting trapped is to make the cubes in layers. Icicles are
made this way; that is why they are usually so clear.
88
Chapter 15 Review
Vocabulary review
Set One
Set Two
Set Three
Set Four
1. c
1. c
1. c
1. b
2. e
2. b
2. e
2. d
3. a
3. e
3. a
3. f
4. b
4. a
4. b
4. e
5. d
5. d
5. d
5. c
Concept review
1.
c
8.
It focuses light on the back of the eye.
2.
a
9.
b
3.
c
10. b
4.
b
11. c
5.
It regulates the amount of light that enters the eye.
12. d
6.
It carries signals from the eye to the brain.
13. c
7.
It changes light into a signal that is sent to the brain.
Problems
1.
d
2.
c
3.
a
4.
b
5.
b
6.
c
89
Chapter 15 Review
1.
Sketches of the eyeball should include the: retina, lens, pupil, cornea,
and optic nerve.
2.
The eyepiece of a microscope includes a lens, the part you look
though. It usually magnifies an image 10 times. Microscopes usually
have more than one objective, each with a different magnification.
These are on a turret which rotates so that you can change the
magnification of the image. The magnification of an image is
obtained by multiplying the eyepiece magnification by the objective
magnification.
3.
A refractor telescope bends light toward the focal point near the
eyepiece as it passes through the lens. The gathered light is
concentrated in this way so that you can see a greatly magnified
image. A reflector telescope uses mirrors instead of objective lenses.
The mirror focuses the light on a focal point near the eyepiece. The
aperture of a telescope is the diameter of the main objective lens or
the mirror in the telescope. Larger apertures gather more light and
make for very bright, detailed images. In telescopes, magnification
can be determined by multiplying the diameter of the objective in
millimeters by 2. For example, a 60 millimeter objective magnifies
120 times.
90
4.
Electrons in the glow-in-the-dark material are moved to a higher
energy level when exposed to light. Eventually they fall and emit
light.
5.
The electrons in an atom become excited so that they “jump” to
higher energy levels. As they drop back from the higher energy level
to a lower (more stable) one, they emit electromagnetic radiation
(sometimes this is in the visible range).
6.
In the curved mirror, images are smaller than normal. People
associate smaller images with being further away. The warning that
objects are “closer than they appear” is a reminder about this
phenomenon.
Chapter 16 Review
Vocabulary review
Set One
Set Two
1. d
1. e
2. f
2. f
3. a
3. d
4. b
4. c
5. e
5. b
Concept Review
1.
Mixtures and substances
6.
The atoms change position as they roll and slide over one another.
2.
Heterogeneous mixtures include pizza, hamburgers, and Caesar salad.
Examples of homogeneous mixtures include tea, apple juice, and
vanilla pudding.
7.
The atoms have sufficient energy to separate from one another. They
spread out to fill their container.
8.
3.
The two kinds of substances are elements and compounds. The
smallest unit of an element is the atom. The smallest unit of a
compound is a molecule.
Liquids retain their size because the atoms or molecules do not have
sufficient energy to bounce out of the solution.
9.
Answers may vary. Correct answers include:
Similarities: both are properties of matter, and both can be measured.
Differences: mass is a measure of the amount of matter, whereas
volume is a measure of how much space is taken up by the matter;
mass is measured in metric units of grams, whereas volume is
measured in metric units of liters.
4.
Molecules are two or more atoms joined together in a compound. An
atom is the smallest particle of an element that retains the properties
of the element. A molecule is the smallest unit of a compound that
retains the properties of the compound.
5.
The atoms constantly vibrate but do not change position.
10. Vaporization is the change in state from a liquid to a gas. Sublimation
is the change in state from a solid to a gas.
Problems
1.
Chip off a piece of the boulder and find its mass and volume. Find the
length, width, and height of the boulder and calculate its approximate
volume. Set up a proportion: chip mass/chip volume = x/boulder
volume. Solve for x where x = the mass of the boulder.
2.
Measure the height of a stack of 100 cards. Divide this measurement
by 100 to find the thickness of one card.
3.
a. solid; b. liquid; c. gas
91
Chapter 16 Review
1.
2.
3.
Refer students to 16.1 Classifying Matter of the Student Edition for a
graphic description of the classification of matter. Matter is
subdivided into mixtures and substances. Mixtures include
homogeneous and heterogeneous mixtures. Substances include
elements and compounds. Students should be encouraged to come up
with a unique way to display the classification of matter. If they use
poster board, have them fill up the entire available space.
Additionally, have your students provide examples for each step in
the classification.
For this project, have students first brainstorm what features of a
model work for a younger group of students. Remind your students
that fourth graders might be unfamiliar with these concepts. The
parts of their model, therefore, need to be very easy to see and
understand. Materials that might work with this project include foam
balls, breakfast cereal, marshmallows, or modeling clay. The items
can be displayed in a clear container such as a plastic shoebox. To
demonstrate molecular movement in a solid, the items could be
connected with toothpicks or wires. The box can be shaken gently to
show that the molecules vibrate but don’t change position. To
demonstrate molecular movement in liquids, the items can be
displayed without connective material. Rotating the box
demonstrates how liquid molecules slide around one another.
Vigorously shaking the same box can demonstrate the movement of
molecules in the gas state. You might also want to have your students
write up a short dialogue for how they would present their model to
their students.
Ask students if they have ever seen land surveyors using
triangulation equipment to measure precise distances. Land
surveyors are often employed in the early stages of construction
projects. For this project, it is useful to have a land surveyor visit
your classroom to talk about how land is measured and mapped.
Have your students visit the web site for the U. S. Geological Survey
(www.usgs.gov) for further information about how topographic
maps are made and used.
92
4.
5.
6.
7.
8.
9.
Answers may vary. Possible answers include:
Large mass, small volume: brick, lead sinker, hand weights.
Small mass, large volume: balloon, large foam blocks.
Answers will vary. Correct answers include:
Volume of rock: place rock in a displacement tank, collect the
overflow, and measure the volume of the overflow in a graduated
cylinder. The volume overflow equals the volume of the rock.
Mass of orange juice: Find the mass of a container. Pour the juice
into the container and find the total mass. Find the mass of the
orange juice by subtraction.
Measure the length, width, and height in cm with a ruler, and then
multiply to find the total volume in cm3. Next, slowly lower the
sponge into a displacement tank. The water will fill the empty
spaces. Collect the overflow, and measure its volume in a graduated
cylinder. Divide the volume of the overflow by the volume of the dry
sponge. Multiply this by 100 to get the percent empty space.
Answers will vary. Any poster or model that clearly shows the
differences in molecular arrangement and movement will provide a
good review for classmates.
Answers will vary. The graphic should show representations of
solids, liquids, and gases before and after heat energy is added or
taken away.
Answers will vary. Most of the matter in the universe is in the plasma
state, and plasmas are a potential source of energy. Inventors have
used plasma to conduct electricity in neon signs and fluorescent
lamps. A plasma generator is a device for transforming electric
energy into heat energy carried by a gas. Scientists have constructed
special chambers to experiment with plasmas in the laboratory. Low
temperature plasmas are being studied for possible use in laser
technology.
Chapter 17 Review
Vocabulary review
Set One
Set Two
1. b
1. d
2. e
2. b
3. d
3. a
4. c
4. f
5. a
5. c
Concept review
1.
Aluminum bats are hollow inside. A solid aluminum bat would have
much greater mass than the wooden bat.
2.
The platinum atoms must be more tightly packed together than those
of copper.
3.
Two properties to consider are brittleness, because a car seat shouldn’t
shatter easily; and elasticity, because a slightly elastic material could
help absorb impact in the event of an accident.
4.
It would sink because solid silver is more dense than liquid silver.
5.
Because the density of Dead Sea water is greater than fresh water, the
force pushing up on me would also be greater. Therefore, it would be
easier to float in the Dead Sea.
6.
There is a direct relationship between the temperature and volume of
a gas. As temperature decreases, volume decreases. As temperature
increases, volume increases. Assuming the pressure remains constant
in the ball, the volume decreased because the temperature decreased.
4.
Answers are:
a. 10.6 cm3 of water is 10.6 g.
10.6 g × 0.0098 N/g = 0.104 N
b. 2.00 N (weight of gold) — 0.104 N (buoyant force of water) =
1.90 N
5.
The equation for Boyle’s law is: P1V1 × P2V2
(2,500 kPa) × (5.0 L) = (X) × (1.0 L)
Pressure in the can = 12,500 kPa
Problems
1.
4 liters = 4000 mL. 4000 mL × 1.7 g/ mL = 2,800 g, or 2.8 kg
2.
The density of the steel is 25 g/3.2 cm3 or 7.8 g/ cm3. The volume of
the 10-g ball bearing is 10 g ÷ (7.8 g/cm3) or 1.3 cm3.
3.
109 cm3; 100 ml
93
Chapter 17 Review
1.
0.90 (8.9 g/cm3) + 0.10(7.3 g/cm3) = 8.74 g/cm3
2.
If the density of ice were greater than water during cold winter
months, ice would form at the bottoms of lakes and ponds. In spring
and summer, when the weather warms, the ice might not completely
thaw in especially deep ponds and lakes (such as the Great Lakes).
Over a series of seasons, ice would form in layers, and these bodies
of water would become blocks of ice. The cooling that one usually
feels near a body of water would be greater because of the presence
of ice. For this reason, areas near large bodies of water might have
colder summers.
3.
Students will need to conduct research to answer this question. Have
them use keywords such as: pressure adaptations, deep-sea
adaptations, atmospheric pressure, deep-sea pressure.
a. Answers will vary. Possible answers include:
Skeleton, skin, pressure of fluids inside the body is in
equilibrium with atmospheric pressure.
b. Answers will vary. Possible answers include:
Hard exoskeleton, regulated vascular system, pressure exerted
by internal fluids is in equilibrium with external pressure,
pressure-resistant proteins.
4.
High hardness, low durability: crystal vase, drinking glass
Low hardness, high durability: rubber ball or tire, plastic watch.
5.
a. strong rubber bands or hair elastics, waistband elastic, stretchy
fabric
b. glass, and many different minerals such as diamond and
tanzanite
c. certain types of glass (not “safety glass”)
d. certain types of taffy candy, “Silly Putty”
94
6.
An internet search using the keywords “Archimedes” + “golden
crown” will lead students to current scholarship about Archimedes’
method. A particularly helpful website is maintained by Drexel
University. You may wish to ask students to make a life-size model
crown using aluminum foil so that they can visualize the size of the
container that would be required to immerse the crown. You can
discuss the advantages of using a displacement tank with a spout
rather than simply letting water overflow the rim of a bowl. Another
useful exercise is to have students use density to calculate the
volume of the crown (assuming its mass was 1,000 grams) if the
crown were pure gold, and again if the crown were made of 70%
gold and 30% silver. This will help them understand the approximate
difference in volume that Archimedes would have seen if the crown
were not pure gold. You may wish to demonstrate the alternative
method proposed by scholars at Drexel University, which involves
hanging the crown from one end of a lever and balancing an equal
mass from the other end. When the items hanging from the lever are
immersed in water, the one with the greater volume will displace
more water, resulting in a larger buoyant force. Therefore it will be
pushed higher in the water than the other item—and differences in
densities will be readily apparent.
7.
Students can study a number of different websites as well as printed
material to learn about the viscosity of different lava flows. The
viscosity of lava flows does vary due to a number of factors,
including temperature of the lava at the time of data collection (was
the lava near the vent, or was it a fair distance away from the vent?)
and how much water, gas, and solid it contains.
Chapter 18 Review
Vocabulary review
Set One
Set Two
Set Three
1. e
1. b
1. c
2. a
2. c
2. e
3. d
3. e
3. f
4. f
4. f
4. d
5. c
5. a
5. a
Concept review
1.
The element is boron.
2.
They are the same element, carbon, because they have the same
number of protons.
3.
The electromagnetic force that causes the protons to repel each other
is overcome by the strong nuclear force, which holds the nucleus
together.
4.
Scientists don’t believe there is an infinite number of elements
because as the nucleus gets larger the protons get further apart. As a
result, the strong nuclear force would no longer operate and the
protons would repel each other, causing the nucleus to break apart.
4.
Answers are:
a. Beryllium, calcium, strontium, barium, or radium (any element
from group two).
b. They all have two full electron levels, plus a third level which is
partially full. Argon, the last element in the third row, has three
completely full levels.
5.
Atom A: chlorine, 35, 17 Cl ; Atom B: calcium, 40,
copper, 63, 63
; Atom D: bromine, 80, 80
35 Br .
29Cu
Problems
1.
The first three levels would be completely filled, and there would be
two electrons left over. They would be found in the fourth level.
2.
The first five levels would be completely full, and there would be no
electrons left over.
3.
Calcium is more likely to combine with other elements because it has
two electrons to give away. Xenon’s shells are completely full, so it
does not need to combine with anything else.
35
40
20 Ca
; Atom C:
95
Chapter 18 Review
1.
Refer your students to the Student Edition (Section 18.1) for this
project. You may wish to ask students to do additional research on
the Internet or in the library. Student answers should reflect that the
Thomson model of the atom reflected his discovery of the electron,
which carries a negative charge. The Rutherford model, based on his
gold foil experiment, introduced the nucleus to the atomic model.
The Bohr model introduced the idea that electrons have fixed
amounts of energy. The Schrödinger model reflected discoveries of
the wavelike nature of electrons.
2.
An example of the Bohr model is shown in the Student Edition
(Section 18.1). The most challenging part of this project will be for
your students to figure out how to show that the electrons orbit in
different energy levels. This aspect of the project makes it suitable as
a group project. Students enjoy working together to solve problems
such as how to accurately model an atom. Challenge them to try to
be as accurate as possible. For an extra challenge, have them see if
they can model an atom with a high atomic number.
96
Chapter 19 Review
Vocabulary review
Set One
Set Two
1. e
1. e
2. c
2. a
3. b
3. d
4. a
4. c
Concept review
1.
With the exception of hydrogen and helium which need only two,
atoms strive to have eight valence electrons. Atoms can achieve eight
valence electrons by forming bonds.
7.
Polymers are large molecules composed of repeating smaller
molecules. Cellulose is a natural polymer from wood and plants.
Plastics are synthetic polymers.
2.
The Group 18 elements, the noble gases, all have eight valence
electrons. For this reason, these elements do not naturally participate
in chemical reactions.
8.
3.
It is easy to figure out the valence electrons for elements in groups 1,
2 and 13-18 on the periodic table. Going from left to right (and
omitting groups 3 - 12, the transition elements), there are 1, 2, 3, 4, 5,
6, 7, and 8 valence electrons in these groups.
An oxidation number indicates how many electrons are lost, gained,
or shared when bonding occurs. The most common oxidation number
for elements is related to the valence number of electrons. Elements in
groups 1, 2, 13, and 14 are more likely to lose their valence electrons.
They have positive oxidation numbers: 1+ to 4+, respectively.
Elements in groups 15 - 17 will gain electrons and have oxidation
number of 3- to 1-, respectively. Group 18 elements have an oxidation
number of 0.
4.
An atom with a complete octet of valence electrons is chemically
stable.
9.
Subscripts indicate the number of atoms of an element in the
molecule.
5.
Ionic bonds involve the gain of electrons by one atom and the loss of
electrons from the other atom participating in the bond. Covalent
bonds involve equal sharing of electrons between atoms.
6.
A bond is likely to be ionic if the participating atoms come from
opposite sides of the periodic table.
10. The formula mass of a molecule is given in atomic mass units (amu).
This number is equal to the mass of the compound in grams. Because
molecules are so small, we work with a set of molecules—Avogadro’s
number of molecules—to find the mass of the compounds in grams.
For example, the formula mass of one molecule of H2O is 18.02 amu.
The mass of 6.02 x 1023 molecules of H2O is 18.02 grams.
97
Chapter 19 Review
Problems
1.
Answers are:
Element
Fluorine
Oxygen
Atomic
number
9
8
Carbon
6
4
7
5
Sulfur
16
6
Silicon
98
14
8
4
Number of
valence
electrons
Electrons
gained or lost
during
ionization
Oxidation
number
Potassium
19
1 lost
1+
Aluminum
13
3 lost
3+
Phosphorus
5
3 gained
3-
Krypton
8
0
0
Element
2
Nitrogen
10
Answers are:
6
5
Neon
3.
7
15
4
Answers are:
a. Covalent; no electronegativity difference.
b. Ionic; metal and a nonmetal, opposite sides of periodic table.
c. Very little electronegativity difference.
d. Covalent; very little electronegativity difference.
e. Ionic; metal and nonmetal, opposite sides of periodic table.
Valence
Lewis dot diagram
electrons
Phosphorus
Beryllium
2.
4.
Answers are:
a. Group 1
b. Group 15
c. Group 14
d. Group 17
e. Group 2
5.
c
6.
a
7.
b
8.
b
Chapter 19 Review
9.
Answers are:
a. empirical
b. molecular; (CH2)(OH)
c. empirical
d. molecular; C5H4O2
12. Answers are:
a. 23 amu + 16 amu + 1.01 amu = 40.01 amu
b. 24.3 amu + 32.1 amu + 4 (16 amu) = 120.4 amu
c. 9 (12.01 amu) + 8 (1.01 amu) + 4 (16 amu) = 180.17 amu
d. 40.1 amu + 2(2)(1.01 amu) + (2)(31 amu) + (2)(4)(16 amu)
= 234.04 amu
e. 40.1 amu + (2)(35.5 amu) + (6)(2)(1.01 amu) + (6)(16 amu)
= 219.22 amu
10. Answers are:
a. N4O6; nitrogen oxide
b. SiO2; silicon oxide
c. S2F10; sulfur fluoride
d. SbCl5; antimony chloride
11. Answers are:
a. NaC2H3O2
b. Al(OH)3
c. MgSO4
d. NH4NO3
e. CaF2
13. Answers are:
a. sodium hydroxide
b. magnesium sulfate
d. calcium chloride hexahydrate
1.
Answers are:
2.
Chemical formula
of compound
Oxidation number
for positive ion
Oxidation number
for negative ion
SiO2
4+
2-
PBr3
3+
1-
FeCl3
3+
1-
CuF2
2+
1-
N2O3
3+
2-
P2O5
5+
2-
Answers are:
a. No. The formula mass of the compounds is 58.5 amu for NaCl
and 102 amu for Al2O3. The mass of Avogadro’s number of
these molecules is 58.5 g and 102 g, respectively.
b. You would use a balance to obtain 58.5 g of NaCl and 102 g of
Al2O3.
c. The atoms that make up each molecule have different formula
masses.
99
Chapter 19 Review
3.
This project can be done by the whole class. Finding out about
recycling policies in the community and school can be delegated
tasks. Students can do preliminary investigative work to find out
what their school and communities do about recycling. Then, they
can do small studies to see if these programs seem to be working.
Finally, they can figure out how they can help improve these
programs and raise awareness about recycling.
4.
Have each student find five chemicals used in their homes. Ask them
to see if they can figure out how to find out more information about
the hazards of using these chemicals. They should discover that
hazardous chemicals have telephone numbers listed on the labels. By
calling these numbers, students can ask a customer representative
specific questions or obtain a materials safety data sheet (MSDS). A
MSDS for a chemical provides extensive information about hazards
of using a chemical and what to do in the event that the chemical is
ingested, inhaled, or spilled. Ask your students what they think the
differences are between environmentally friendly household
chemicals and those that aren’t labeled in this way.
100
Chapter 20 Review
Vocabulary review
Set One
Set Two
Set Three
1. c
1. c
1. f
2. e
2. b
2. c
3. d
3. a
3. e
4. b
4. e
4. b
5. d
Concept review
1.
Physical changes result in a change of size or shape. Chemical
changes result in different substances being formed. Atoms are
rearranged, and often energy is released or absorbed in chemical
changes.
2.
Examples of a physical change include cutting something in half,
evaporating water, or melting a substance.
3.
Examples of a chemical change include striking a match, forming a
precipitate by mixing two salts, and mixing vinegar and baking soda.
4.
Answers will vary. Students should discuss that recipes and reactions
have starting materials and products, and both usually require an input
of energy. Both recipes and reactions identify the proportions of
reactants or ingredients involved. Differences include that not all
recipes involve chemical changes whereas all chemical reactions do.
Recipes make products that are edible while chemical reactions can
produce toxic substances. The conditions under which a reaction
works are often not provided in a written chemical equation.
5.
In chemical reactions, atoms are rearranged. This means that the
bonds in reactant molecules must be broken and new ones formed to
make product molecules.
6.
The number and kinds of atoms in the reactants of a reaction must
equal the number and kinds of atoms in the products. Atoms are
rearranged, not created, in chemical reactions.
7.
Lavoisier established the law of conservation of mass through careful
experimentation. He recognized that mass is conserved in chemical
reactions; the mass of reactants equals the mass of the products.
8.
Answers will vary. A chemical equation tells you the kinds and
quantities of reactants that are required to perform the reaction. The
kinds and quantities of products in the reaction are also provided.
Balanced equations show the ratio of the relative masses of all the
molecules reacting or being produced in the reaction. Finally,
equations illustrate that mass and atoms are conserved in reactions.
101
Chapter 20 Review
9.
A limiting reactant is the reactant that is in short supply in a reaction.
The amount of product produced is limited by this one substance in
the reaction. Often a reactant is added in excess of what is needed.
This is to make sure this (often less expensive) reactant does not
limit the overall reaction.
10. Answers will vary. Possible answers may be that portions of the
reactants are sometimes lost over the course of performing a
reaction. Additionally, it is sometimes difficult to fully recover the
entire amount of product. In some experiments, it is difficult to
“trap” the product, especially if it is a gas. Finally, measurements
throughout an experiment may not be accurate enough. Inaccurate
measurements can lead to experimental error.
Problems
1.
c
2.
c
3.
d
4.
b
11. Answers are:
a. Cl2 (g) + 2KBr (aq)
b. 4NH3 (g) + 5O2 (g)
5.
6.
c
7.
b
8.
d
9.
3
type
of atom
total on
reactants
side
total on
products
side
balanced?
(yes or no)
Al
1
1
yes
Br
2
3
no
10. Answers are:
a. Cl2 + 2Br
b. Balanced
c. Na2SO4 + BaCl2
d. 2ZnS + 3O2
102
2KCl(aq) + Br2(l)
4NO (g) + 6H2O (g)
12. Answers are:
a. 4NH3: 4 × 17.0 amu = 68.0 amu
b. 5O2: 5 × 32.0 amu = 160.0 amu
c. 4NO: 4 × 30.0 amu = 120.0 amu
d. 6H2O: 6 × 18.0 amu = 108.0 amu
13. Answers are:
a. 68.0 grams
b. 160.0 grams
c. 120.0 grams
d. 108.0 grams
14. 20 grams O2/160 grams O2 = predicted grams of H2O/108 grams
H2 O
0.125 × 108.0 grams H2O = 13.5 grams is the predicted yield for
H2 O
2Cl + Br2
BaSO4 + 2NaCl
2ZnO + 2SO2
15. 10 grams Cl2/(1 × 71 grams Cl2) = predicted grams of Br2/(1 x 160
grams Br2)
0.14 x 160 grams Br2 = 22.5 grams is the predicted yield for Br2
percent yield: 19.8 grams/ 22.5 grams × 100 = 88%
Chapter 20 Review
1.
Steps that involve physical changes include chopping vegetables,
mixing oil and vinegar, and tearing lettuce. The major example of a
chemical change is digesting the salad!
2.
Answers are:
a. Chemical
b. Chemical
c. Physical
d. Physical
e. Chemical
3.
461.5 grams/500 grams × 100 = 92.3% yield of aspirin
4.
Answers are:
a. Carbon
b. Oxygen
c. Methane
5.
Answers are:
a. 10
b. The cherries
c. 5 cups of ice cream and 5 ounces of chocolate sauce
6.
Research on the Internet is helpful in figuring out the reactants and
products for everyday reactions. Students should use key words that
include the topic along with the word “reaction”.
Possible answers include:
Breathing (Respiration). Reactants = sugar and oxygen; products =
carbon dioxide and water.
Driving a car. Reactants = octane and oxygen; products = carbon
dioxide and water.
Rusting. Reactants = iron and oxygen; products = iron oxide.
7.
Research on the Internet will be helpful in figuring out the reactants
and products for the chemical reactions used in industry. Students
should first brainstorm industries, and then use the names of each
industry as key words in their search. Alternatively, college level
chemistry textbooks often discuss the chemical reactions used in
industry and other applications.
Some example reactions include:
Airbag reactions. This is a three step reaction. The primary reactant
is sodium azide (NaN3), potassium nitrate (KNO3), and silica (SiO2).
These are ignited electrically and release a precalculated amount of
nitrogen gas (N2) which fills the airbag.
Manufacture of aspirin. Reactants are salicylic acid and acetic
anhydride. Products are aspirin (acetylsalicylic acid) and acetic acid.
103
Chapter 21 Review
Vocabulary review
Set One
Set Two
1. f
1. e
2. d
2. d
3. e
3. a
4. a
4. c
5. c
5. f
Concept review
1.
Exothermic
2.
Answers are:
a. Addition
b. Exothermic
3.
Less energy is required to break the bonds in the reactants than is
released when bonds are formed to make new products. Energy is
always released and can be detected by a rise in temperature during
the reaction.
4.
b
3.
Answers are:
a.
BaSO4
b. Zn3(PO4)2
c. No precipitate
d. No precipitate
Problems
1.
2.
Answers are:
a. Double-displacement
b. Addition
c. Decomposition
d. Combustion
e. Single-replacement
Answers are:
a.
b.
c.
d.
104
H2SO4(aq) + BaCl(aq)
BaSO4 + H+ + ClZn3(PO4)2 + Na2SO4
ZnSO4(aq) + Na3PO4(aq)
HCl (aq) + K2SO3
KCl + H2SO3
SnCl2 + Fe2(SO4)3
Sn2(SO4)4 + FeCl2
Chapter 21 Review
4.
Answers are:
a. Fe(s) + CuCl2(aq)
b. 2C2H6(g) + 7O2(g)
c. NaCl(aq) + NH4OH(aq)
2H2 + O2
d. 2H2O
FeCl2 (aq) + Cu(s)
4CO2(g) + 6H2O(l)
NaOH(aq) + NH4Cl (aq)
e.
f.
g.
h.
2Cu(s) + O2(g)
2CuO
4Al(s) + 3O2(g)
2Al2O3
Mg(s) + 2HCl(aq)
MgCl2 + H2
2LiNO3(aq) + MgCl2(aq)
2LiCl + Mg(NO3)2
1.
Answers are:
a. Single-displacement
b. Exothermic
c. Al + 3NaOH
2Na+ + H2O
Al (OH)3 + 3Na+
Na2O + H2
2.
The combustion of propane:
3CO2 + 4H2O + energy
C3H8 + 5O2
3.
Light bulbs are constructed so that the tungsten filament inside never
comes in contact with oxygen in the air. Argon gas is usually the only
gas inside light bulbs.
105
Chapter 22 Review
Vocabulary review
Set One
Set Two
1. c
1. a
2. a
2. d
3. d
3. b
4. f
4. c
5. e
5. f
Concept review
1.
Fission involves the splitting of a radioactive nucleus into a lighter,
more stable nucleus. Fusion involves two nuclei combining to form a
larger nucleus. Atoms with atomic numbers larger than 92 are
unstable and spontaneously undergo fission (radioactive decay).
Fusion happens naturally in the sun because of available hydrogen
nuclei. These nuclei overcome electromagnetic repulsion and fuse,
creating a huge amount of energy.
2.
Nuclear reactions involve the nuclei of atoms whereas chemical
reactions involve the outermost electrons. Chemical reactions
involve the breaking or formation of bonds between atoms. In
nuclear reactions, nuclei fuse or split apart. Nuclear reactions
produce many more times the energy than exothermic chemical
reactions.
3.
3
In alpha decay, two protons and two neutrons are released from an
atomic nucleus. The released particle is a helium nucleus. After an
atom undergoes alpha decay, the mass number of the resulting atom
is 4 less than it was, and the atomic number is 2 less. In beta decay, a
neutron decays to a proton and electron. The proton remains behind
in the nucleus; the electron is emitted. The mass number of the
resulting atom is the same, but the atomic number has increased by
1.
5.
These reactions are the reverse of each other, as shown:
Photosynthesis: 6CO2 + 6H2O → C6H12O6 + 6O2
Respiration: C6H12O6 + 6O2 → 6CO2 + 6H2O
6.
The Earth’s atmosphere contains 78% nitrogen, 21% oxygen, and
0.036% carbon dioxide, 1% argon and some water vapor.
2
Answer: 1H (2 neutrons, 1 proton, 1 electron), 1H (1 neutron, 1
1
proton, 1 electron), and 1H (0 neutrons, 1 proton, 1 electron).
106
4.
Chapter 22 Review
7.
The most significant global warming gas is CO2. The combustion of
fossil fuels by cars is a large source of CO2. Our extensive use of cars,
therefore, is one of the leading reasons for why the level of CO2 in the
atmosphere is increasing.
8.
Commonly used plant products include paper, wood, cotton, linen,
fruits, vegetables, flowers, vegetable oil, olive oil, and peanut butter.
4.
The plant gained weight because it used photosynthesis to convert
carbon dioxide into C6H12O6 which was then converted to wood.
5.
Only a small amount of gold can be produced from fission and fusion
using these methods. To produce gold in either of these ways is
expensive and time consuming. With present technology and
understanding, it would be exceedingly difficult to get rich by making
gold from fission and fusion. Gold is less expensive to mine.
6.
The half-life is 6 days.
7.
Answers are:
a. Cesium-137 has 55 protons and 82 neutrons. After beta decay, it
has 56 protons, 81 neutrons and becomes barium-137.
b.
Problems
1.
(The following reactions are hypothetical. For information about the
decay
of
radioisotopes,
you
may
want
to
check
www.webelements.com.)
196
1
197
a. Fusion: 78Pt + 1H --> 79Au
197
197
b. Fission: 78Pt --beta decay--> 79Au
2.
At 9 months, the isotope is half its original amount. Therefore, the
half-life for this radioactive isotope is 9 months.
3.
In the answers below, “a” is alpha decay and “b” is beta decay.
a. 238 U
a→
234 Th
90
b→ 234 Pa b→ 234 U
226 Ra
88
a→
222 Rn
86
a→
a→
214 Pb
82
b→ 214 Bi b→
214 Po
84
a→
210 Pb
82
Bi b→
b→ 210
83
210 Po
84
a→
236 Np
93
a→
232 Pa
91
U
b→ 232
92
At a→
a→ 216
85
92
92
91
Pu b→ 405Am a→
b. 240
94
218 Po
84
228 Bi
90
a→
224 Ra
88
Ac a→
b→ 224
89
220 Fr
87
212 Bi
83
b→
212 Po
84
a→
208 Pb
82
208Bi
83
b→
a→
230 Th
90
a→
83
206
Pb
82
a→
107
Chapter 22 Review
1.
Fifty percent of remaining gold ore reserves are in South Africa. The
rest of the reserves are in Russia, Canada, Australia, Brazil, and the
United States. The largest gold ore body in the world is in the
Witwatersrand, South Africa.
2.
Most debate formats involve time-limited exchanges between the pro
and con side. The sides are graded on the aspects of their
presentations that help make their points. Research different debate
formats to find one that works best for your class. In particular,
search for a format that includes the “audience” in the exchange of
ideas and grading of the debate.
3.
The four basic forces in the universe are electromagnetism, strong
nuclear force, weak nuclear force, and gravity. Electromagnetism
and strong nuclear force hold atoms together. For example, strong
nuclear forces between nucleons (protons and neutrons) in the
nucleus of an atom help keep the positively charged protons from
flying apart. Electromagnetism is a combination of electrical and
magnetic forces. It keeps electrons attracted to the nucleus and is
involved in bonding. Weak nuclear force is involved in radioactive
decay.
4.
Gravity is the attractive force between masses of matter; this force
exists over large distances.The Earth’s atmosphere is about 78% N2,
21% O2 and 0.036% CO2. The composition of gases on Mars
(including its small atmosphere, crust, and ice) is 2.7% N2, 1.3% O2,
and about 95% CO2. The atmosphere on Venus is 3.5% N2, less than
0.01% O2, and about 97% CO2 (the atmospheric pressure on Venus
is 90 times Earth’s).
108
5.
Articles about global warming can be found in newspapers or
popular scientific magazines. Point out to students that global
warming is still a controversial issue. Ask your students why this is
the case. When each of your students has completed this project,
have a discussion about this environmental issue. Point out to
students that scientists and international leaders meet annually to
discuss climate change.
6.
To start this project, have students look at other kinds of brochures.
Ask them what design features work and do not work. Encourage
them to decide first on the message that they want to convey and
then to figure out the best way to present that message. As students
research this issue, encourage them to examine the economic impact
of allowing global warming to continue as well as the economic
impact of the measures needed to reverse the global warming trend.
The EPA website www.epa.gov/students/global_warming_us.html
provides a helpful overview of the subject.
Chapter 22 Review
7.
The Clean Air act can be read in its original or “plain English” version
on the Internet at http://www.epa.gov/oar/oaq_caa.html.
Chemical reactions that result in airborne pollutants include:
Burning of coal (produces sulfur dioxide)
Burning of gasoline (produces carbon monoxide and nitrous oxides)
Burning of wood (produces particulate matter and carbon monoxide)
Five things companies can do to reduce pollution:
1. Convert coal-burning power plants to natural gas
2. Mix oxygen into gasoline (this is called “oxyfuel”) for more
complete combustion. Less carbon monoxide is produced this way.
3. Add “detergents” to gasoline to keep engines running smoothly so
that they burn fuel more completely.
4. Sell alternative fuels such as alcohols and liquefied petroleum gas.
5. Redesign the burning systems of woodstoves for home heat so that
less pollution is released.
Five costs to society of airborne pollutants:
1. Damage to buildings due to acid rain. (Repair costs paid by
property owners).
2. Increased incidence of childhood asthma and other respiratory
ailments (Health care costs paid by consumers through private
insurance and by public health care programs).
3. Increased incidence of skin cancers due to exposure to UV-B rays
as a result of thinning ozone layer in Earth’s stratosphere (Health care
costs paid by consumers through private insurance and by public
health care programs).
4. Damage to food supplies. For example, mercury emissions from
coal burning power plants have contributed to rising mercury levels in
the tissues of large fish such as tuna and salmon in the North Atlantic
Ocean. If the levels get high enough, people reduce their intake of
these types of food. The fishing industry pays a cost in terms of lost
sales and the cost of buying new equipment to fish for other species.
5. Lost time due to flight delays. Airborne pollutants sometimes cause
such severe haze that airplane flights are delayed or cancelled. (Costs
paid by individuals and businesses as, for example, meetings are
delayed or cancelled).
109
Chapter 23 Review
Vocabulary review
Set One
Set Two
Set Three
1. c
1. b
1. b
2. e
2. f
2. d
3. a
3. a
3. c
4. f
4. e
5. d
5. c
Concept review
1.
Air
6.
2.
Suspensions can be separated by filtering, but colloids cannot.
Suspensions settle upon standing, but colloids do not.
A precipitate begins to form and continues until the solution reaches
the point of saturation.
7.
The solubility increases due to the increased molecular motion of the
water.
Heat the water, shake or stir the container, and increase the surface
area of the sugar by crushing the crystals.
8.
Temperature goes on the x-axis and solubility values go on the yaxis.
9.
Solutions are at equilibrium when the number of solute molecules
dissolving is the same as the number of molecules crystallizing
(coming out of solution).
3.
4.
5.
The solubility of oxygen increases as temperature decreases. Gases
are more soluble in liquids at lower temperatures because molecular
motion is slowed. For this reason, gases are less likely to escape
from liquid solvents at lower temperatures.
The warmer soda is more likely to spill over because the liquid
cannot hold as much dissolved gas as it can at a lower temperature.
110
Chapter 23 Review
Problems
1.
600 cm2
2.
1200 cm2
3.
Answers are:
a. 280 mL of water
b. 35.7 g NaCl
4.
Answers are:
a. About 40 g/100mL
b. NaNO3
c. NaCl
d. NaNO3
4.
Gas expands under lower pressures. As a diver changes his or her
depth while diving, keeping the mouth open allows for gases to take
up more or less room in the lungs. Gases that can’t escape from the
lungs might cause the lungs to rupture.
1.
The instructions for how to make rock candy are provided in the
student edition. Safety instructions include tips on how to work with
hot water and warnings to not eat the rock candy unless the activity
takes place in a kitchen with clean materials. Food should never be
eaten in a laboratory. Definitions for the terms are in the glossary and
student reading.
2.
Possible answers are:
a. A medicine that dissolves quickly would have a large surface
area (it could be a powder or a small tablet). This medicine
should include ingredients that dissolve in water. Having the
medicine be effervescent (by including baking soda as an
ingredient) would be useful, as well as recommending that the
medicine be dissolved in hot or warm water.
b. A medicine that is timed-released might be a tablet that has
layers that have different dissolving rates to slow down the
dissolving process of the entire tablet. For example, each
medicine layer of the tablet could be separated by a material that
is not medicinal and dissolves slowly.
3.
The “test” described is commonly used between divers to check for
nitrogen narcosis. The confused diver has nitrogen narcosis which is
“cured” by coming slowly to the water’s surface.
111
Chapter 24 Review
Vocabulary review
Set One
Set Two
Set Three
1. a
1. b
1. d
2. f
2. d
2. e
3. d
3. c
3. c
4. e
4. a
4. a
5. b
5. f
5. b
Concept review
1.
The diagram is:
2.
The diagram is:
3.
Oil is a nonpolar molecule. It does not have partial charges. Water is
polar and has a separation of partial charges. Water, a polar molecule,
can dissolve other molecules that have partial charges but not
molecules that are nonpolar.
112
4.
Answers will vary. Water dissolves many things including sugars,
proteins, and salts. Much of what we consume is a solution of some
kind. The fluids in the human body are solutions. However, water
does not dissolve fats, oils, and some salts. Therefore, it is more
correct to say that water is a nearly universal solvent.
5.
Answers will vary. The Earth has a finite amount of water.
Therefore, the processes of the water cycle are crucial for moving the
available water around the planet. In a sense, the water cycle is the
ultimate recycling program. Through evaporation and by filtering
through soils, contaminants are removed from water.
Chapter 24 Review
Problems
1.
Answers are:
a. 2H2 (g) + O2(g) → 2H2O
b. Bonds between the hydrogen atoms in hydrogen gas and the
bonds between the oxygen atoms in oxygen gas need to be
broken. Bonds are formed between oxygen and hydrogen atoms.
2.
Answers are:
a. P
b. N
c. N
d. P
e. N
f. P
3.
Answers will vary.
1.
The ink in the pen does not dissolve in water. The ink may be a
nonpolar substance.
2.
The ingredients in hair spray and alcohol are nonpolar. These
substances can dissolve other nonpolar substances like ink.
3.
Answers will vary. Encourage students to be creative.
4.
Answers will vary. The water on Earth does not diminish. However,
humans are capable of polluting their water. Often it takes a long time
for water to move through the water cycle to get “cleaned,” and it is
expensive to purify water through other means. In this sense, our
water supply can be diminished (or made unavailable) by our own
actions. In addition, water is unevenly distributed on Earth. This is
why some areas are very dry and have little rainfall.
5.
This project lends itself to a class activity. Delegate jobs to groups of
students. Have the class work together to write a report (with
graphics) about the history and present status of their community’s
water supply.
6.
As alternatives to this project, take a class trip to a zoo (or aquarium)
and meet a specialist whose job it is to maintain water quality at the
zoo (or aquarium). Discuss with your class whether they think it
would be easy or difficult to mimic the water quality of the natural
environment.
Discuss whether it is useful to have really clean water. What good
substances might be in water that help animals survive? Also, point
out that although some animals might not live in water, they might
rely on other animals that do. How might a zoo or aquarium create
food chains in their exhibits?
7.
(a) — (c) Benefits of bottled water services include convenience,
consistent taste, and no need to worry about ingesting lead leached
from pipes in buildings. Drawbacks include the cost (more than 90%
of the cost is to cover packaging, shipping, advertising, and profit, not
water itself), greater tooth decay among users caused by lack of
fluoride in the water, and the negative environmental impact of
packaging and shipping bottled water.
(d) Inferences as to why people might purchase bottled water:
Advertising may have convinced consumers that bottled water is a
healthier choice than tapwater. Busy lifestyles may leave consumers
with little time to study the differences between their tap water and
bottled water. Consumers may not know how to get their tap water
tested for lead, so they may feel safer buying bottled water.
(e) Inference as to why someone might not buy bottled water: Some
consumers may value fluoride protection against tooth decay more
than the perceived safety or the consistent taste of bottled water.
113
Chapter 25 Review
Vocabulary review
Set One
Set Two
1. a
1. b
2. f
2. f
3. e
3. e
4. c
4. d
5. d
5. c
Concept review
1.
Acidic foods include tomatoes, lemons and other citrus fruit,
vinaigrette salad dressing, and apple juice.
2.
A strong acid has an extremely high concentration of H+ ions and
ranges in pH from 1 to 3. An example is hydrochloric acid, pH 2. A
weak acid has a lower concentration of H+ ions and ranges in pH
from 4 to 6. An examples is seltzer, pH 4.
6.
Chemicals that conduct current when dissolved in water are called
electrolytes. These chemicals form ions when dissolved and can be
acids or bases. Non-electrolytes do not form ions when dissolved and
are not acidic or basic.
7.
A strong base has an extremely high concentration of OH- ions and
ranges in pH from 12-14. An example is lye, pH 13. A weak base has
a lower concentration of OH- and ranges in pH from 8-11. An
example is a baking soda solution with a pH of 8.5.
With a lot of dissolved CO2, your blood becomes more acidic. When
your blood does not have much dissolved CO2, your blood becomes
more basic. Holding your breath or breathing very slowly causes a
build up of CO2. Hyperventilating forces you to blow off too much
CO2, making your blood too basic.
8.
4.
Water can be considered to be both a weak acid and a weak base. It
contributes H+ and OH- in equal proportions. The pH of water is 7.
It is a neutral solution.
Rain and other forms of precipitation are slightly acidic naturally
because CO2 mixes with and acidifies condensed water in the
atmosphere.
9.
The sulfur and nitrogen oxides: SO2, SO3, NO, NO2
5.
If the pH of a solution is 4, the concentration of H+ is 10-4 moles/
-10 moles/liter. In less
3.
liter. The concentration of OH- ions is 10
precise terms, a solution at pH 4 has 1,000 more H+ ions than water
and 1,000 times less OH- ions than water. Knowing the pH allows
you to figure out the concentration of OH- ions.
114
10. Sulfuric acid and nitric acid.
11. The gases cause respiratory ailments before contributing to the
formation of acid rain. Acid rain harms aquatic life in ponds and
lakes, damages trees, and erodes buildings and statues.
Chapter 25 Review
Problems
1.
Solution A is ten times more acidic than solution B.
2.
Solution B has ten times more OH- ions than solution A.
3.
Solution C has 1,000 times more H+ ions than solution D.
4.
You need twice as much of solution F as you have of solution E. You
would add 20 milliliters of solution F to the 10 milliliters of solution
E.
5.
H+ + OH- <=> H2O
1.
An antacid is a basic substance that can help neutralize acid in the
stomach. Sometimes too much acid is produced by the stomach and
causes a stomach ache. Also, a stomach ache can be caused if too
much acidic food is consumed.
2.
When diabetics lack insulin (needed to get energy from glucose), they
rely on fat for their energy stores. Ketone acids are produced by the
metabolism of fat.
3.
Students could make a graph of the number of tadpoles in the pond
versus year and a graph of pH value for the pond versus year. By
overlaying these graphs, it might be evident that as pH increases, the
number of tadpoles decreases. This might indicate an inversely
proportional relationship between these two variables. As a second
step, students could design an experiment to test the effect of
solutions of different pH on frogs and tadpoles.
4.
This project lends itself to a class research effort. You may want to
delegate each of the bulleted questions to separate groups of students.
As they research, encourage your students to use other accepted terms
that apply such as “acid precipitation” or “acid deposition.” The term,
acid deposition, refers to the fact that gases and solids that descend on
the Earth’s surface can also be acidic for the same reasons that acid
rain is acidic. The pH of acid rain is less than that of rain which ranges
from pH of 5.0 to 5.6. With pH values of 3 to 4.3, acid rain in the
United States can be 10 to 100 times more acidic than normal rain.
Acid rain is a regional problem. Your community may be affected if it
is downwind of cities, industrial sights, or coal-burning power plants.
These places tend to produce sulfur dioxide (SO2) and nitrogen oxides
(NO and NO2) which then combine with components of the
atmosphere to form sulfuric an nitric acids.
Acid rain affects the environment for humans and other living things
in a number of ways. When a lake is acidified, mercury compounds
can be converted to toxic methylmercury. Methylmercury is soluble in
the fatty tissues of fish. Fish that ingest methylmercury from their
environment, accumulate this toxic substance. The contaminated fish
are then harmful to animals and humans that eat these fish. Acids in
the air may also be harmful or irritating to those with respiratory
illnesses such as asthma and bronchitis. In ecological systems, both
the leaves and roots of trees can be harmed by acid rain. Affected
trees tend to be more susceptible to disease.
Economic costs associated with acid rain include the cost to monitor
the problem and find solutions, health costs, and the cost of
maintenance and repair of damaged buildings and monuments.
The best way to address acid rain may be preventative measures such
as lowering our reliance on coal-burning power plants by choosing
other energy sources, and driving less (using public transportation
more). Acid rain is address by the Clean Air Act which is enforced by
the Environmental Protection Agency. For maps of the U.S. that show
how acid rain is distributed, see the Internet site: http://
nadp.sws.uiuc.edu.
115
Chapter 26 Review
Vocabulary review
Set One
Set Two
Set Three
1. d
1. b
1. d
2. a
2. d
2. c
3. e
3. a
3. a
4. f
4. e
4. f
5. b
5. c
5. b
Concept review
1.
Temperature is a measure of the average kinetic energy of the
molecules of a substance. It quantifies how hot or cold a substance
is.
2.
The volume increases.
3.
The length increases.
4.
Heat is the flow of energy from one object to another due to a
temperature difference.
5.
Thermal energy is the sum of kinetic and potential energies of the
atoms or molecules of a substance.
6.
Water has a high heating constant, which means it takes a large
increase in energy to raise the temperature of water as compared to
other substances.
7.
c
8.
d
9.
d
10. The average kinetic energy of the molecules in a substance increases
as the temperature of the substance increases. In most cases, the
collisions between the molecules in the substance cause the
substance to expand in size.
11. Thermal equilibrium occurs between two or more objects when they
have reached the same temperature.
12. The law of conservation of energy states that energy lost by one
object in an isolated system equals the energy gained by the other
object in the system.If two objects are in an isolated system, heat loss
from one object will equal the heat gained by the other object.
13. The liquid inside of thermometers (either alcohol or mercury)
expands with temperature. The thermometers are especially designed
so that the expansion of the liquid is directly proportional to the
change in temperature. The thermometer attains thermal equilibrium
with its surroundings; a thermometer takes its own temperature.
14. b
15. b
16. b
116
Chapter 26 Review
Problems
1.
T = 5/9 × (TF - 32)
9T/5 = TF - 32
TF = 9T/5 + 32 = 0 + 32 = 32°F
2.
T = 5/9 × (TF - 32) = 5/9 × (451 - 32) = 233°C
3.
T = 5/9 × (TF - 32)
9T/5 = TF - 32
TF = 9T/5 + 32 = (9 × 5,500/5) + 32 = 9,932°F
4.
Answers will vary. Students should use the formula:
5
T = --- × ( T F – 32 )
9
5.
Q = mc∆T
∆T= Q ÷ mc = 5,000 cal ÷ (500 g × 1 cal/g°C) = 10°C
6.
Q = mc∆T = 200 g × (1 cal/g°C) × 12°C = 2,400 cal
7.
Answers are:
a. Power = Change in energy ÷ change in time
Change in energy = power × time
Change in energy = 900 W × 120 sec = 108,000 J
b.
c.
Efficiency = thermal energy ÷ electrical energy
Thermal energy = electrical energy × efficiency
Thermal energy = 108,000 J × 0.30 = 32,400 joules
Q = mc∆T
∆T = Q ÷ (m × c)
m = 1 kg; Q = 32,400 J; c = 4186 J/kg
∆T = 32,400 J ÷ (1 kg × 4186 J/kg°C) = 7.7°C
8.
(1 L × 10°C) + (4 L × 80°C) / 1 L + 4 L = 330/5 = 66°C
9.
(1 L × 20°C) + (3 L × 80°C)/ 1 L + 3 L = 260/4 = 65°C
10. Q = mc∆T = 1,000 g × (1 cal/g°C) × (65°C - 20°C) = 45,000 cal
11. Q = mc∆T = 2,000 g × (1 cal/g°C) × (60°C - 40°C) = 40,000 cal
12. Answers are:
a. There is more thermal energy in the aluminum than in the gold.
b. The beaker that contains the aluminum is warmer than the beaker
that contains the gold.
c. The specific heat of aluminum is higher.This means that it
absorbs more energy when it is heated, and can transfer more
energy to a cooler object.
1.
As the water in the radiator gets hot, it expands. The overflow
accommodates the expansion of the water. A water pump is included
in the design to return overflow back to the radiator.
2.
When the air temperature in the root cellar drops below the water
temperature, heat transfers from the water to the air, making the air
warmer. The water acts as a space heater.
3.
The energy of atoms can approach zero at negative 273°C. It is not
possible to keep on lowering the temperature past this point.
4.
Project responses will vary. In their paper or presentation, encourage
students to be creative. For example, a paper can be written from a
scientist’s point of view. For the presentation, students can play the
role of the scientist or demonstrate how the scientist would have
performed his experiments.
117
Chapter 27 Review
Vocabulary review
Set One
Set Two
1. b
1. e
2. f
2. d
3. a
3. c
4. c
4. b
5. d
5. a
Concept review
1.
Similar to electrical conductors, good thermal conductors are dense
(as in a solid) and have many loose electrons. Any kind of metallic
object is a good example.
6.
During the day, a sea breeze is created when the land is much hotter
than the water. Hot air over the land rises and is replaced by cooler
air from the ocean.
2.
Similar to electrical insulators, thermal insulators contain air pockets
or have a molecular structure with no loose electrons. Examples are
ceramic (as in coffee cups), plastics, and wood (as in spoons).
7.
In the evening, the ground cools rapidly, but the ocean remains warm
(due to water’s high specific heat). Warm air now rises over the
water and is replaced with cooler air from the land.
3.
Similar to the electrical properties, air is a bad conductor because of
the large spaces between the molecules. Styrofoam, home insulation,
and down jackets are examples of air pockets. Another example is a
thermos, which has a layer of air.
8.
In forced convection, air is blown by a fan or sucked with a vacuum.
Forced convection is used in heating and air-conditioning systems.
9.
Hotter objects have more energy per molecule than cooler objects.
Thus, they also emit higher energy photons than cooler objects. The
higher the energy of the photon, the higher its frequency. Ultraviolet,
violet, and blue photons have a higher frequency than yellow,
orange, and red photons.
4.
Hot air rises because it is less dense than cool air. When a fluid (gas
or liquid) is surrounded by a denser medium, it rises because of the
force of buoyancy.
5.
Convection only occurs in gases and liquids. Convection does not
occur in a solid because the molecules are locked together in a
structure. Convection depends on the fluidity of molecular motion.
118
10. Black and dark objects tend to absorb light.
11. Objects that are good conductors make good reflectors. Also, white
and light-colored objects make good reflectors.
Chapter 27 Review
Problems
1.
2.
The hot water transfers its heat to the relatively cooler metal of the
cup. By the process of conduction, the heat is transferred to the handle
which is not in contact with the liquid. This process might happen
quickly since metal is a good conductor. However, if the handle were
made out of a good insulator, the heat transfer would not occur
effectively enough to make the handle hot.
3.
The blue star is the hottest. The red star is the coolest.The energy of
light is lowest in the red end of the spectrum and highest in the blue
end of the spectrum.
4.
The following materials are ranked from lowest to highest thermal
conductivity: The thermal conductivity is provided in parentheses
next to each material in units of watts/meter°C.
air (0.025), asbestos (0.1), wood (0.1), rubber (0.2), water (0.6), glass
(0.8), concrete (1.2), aluminum (240), gold (310), copper (400), silver
(430). The materials with low thermal conductivity (1.2 and lower)
are better thermal insulators. They are not very dense (like air), tend
to have air pockets, and do not have free electrons for transferring
kinetic energy. The metals have higher thermal conductivity. They are
better at conducting heat and electricity because they have free
electrons that can easily transfer kinetic (and electrical) energy.
Therefore, silver is the best material to use in a heat sink and air is the
worst.
3.
This project can be done with the whole class. Divide the class into
groups. Have each group decide where they will place the thermostat.
Have them justify their answer. Have each group present their ideas.
Have the class as a whole decide on the best place to put the
thermostat.
4.
Section 27.1 Conduction in the Student Edition contains a diagram of
a double-paned window. Encourage students to use this diagram for
ideas but to not copy it. Rather, challenge your students to find out
how to improve this design.
By forced convection, water can be heated and then pumped through
a house through a system of pipes and radiators. The heat from the
water in the pipes heats the air in the rooms of the house at the level of
the floor. By natural convection, heated air rises toward the ceilings in
the house and pushes the cooler air down towards the floor to be
heated. As the warm air near the ceiling cools, it sinks back to the
floor to be reheated.
1.
2.
Heat from the metal parts of the engine are transferred to the water
being pumped through the engine by conduction. Water is pumped
through the engine by forced convection. The water that returns to the
radiator from the engine is cooled by the air blowing through the
radiator by conduction. If you open the hood of a car while the engine
runs, you feel heat from the engine due to convection (warm air
rising) and from the radiation of heat given off from the radiator.
As water on the bottom of the tank is heated, it rises in the tank. At the
top of the tank, the water cools again. Heating at the bottom of the
tank forces the water to circulate efficiently so that the whole tank
gets heated.
119
Chapter 28 Review
Vocabulary review
Set One
Set Two
Set Three
1. f
1. c
1. d
2. d
2. d
2. e
3. a
3. e
3. a
4. e
4. b
4. b
5. b
5. f
5. c
Concept review
1.
Topography is a description of the type of land such as desert,
swampland, mountains, or coastal region.
2.
If the temperature goes below the dew point, the air is saturated with
water vapor, and condensation occurs. This leads to the formation of
fog or clouds. Dew point is the temperature at which an air and water
vapor mixture is 100% saturated with water.
6.
In cellular combustion (respiration), oxygen and sugar are combined
to produce carbon dioxide, water, and heat:
6O2 + C6H12O6 = 6CO2 + 6H2O + heat
7.
Friction, deformation, and fluid resistance.
8.
Heat loss can be reduced by the use of a lubricant such as oil or by
the use of ball bearings in systems where rotation is required. Of
course, wheels or rollers can reduce friction in any system where an
object needs to move. An air cushion can also reduce friction.
See the Student Edition for a full explanation on the internal
combustion engine.
3.
The percentage of water vapor currently in the air compared to the
air’s total capacity to hold water.
4.
Scientists calculate the amount of energy stored in food by burning
the food and measuring how much heat is released.
9.
5.
Fat has the most calories per gram (9,000 calories per gram, or 9
Calories per gram). Protein and carbohydrates have 4,000 calories
per gram (4 Calories per gram).
10. See the Student Edition for a full explanation on the steam engine.
Problems
1.
Answers should reflect that cities in the south such as Miami,
Houston, and Los Angeles are warmer than Chicago, New York, or
Boston. This is because the northern cities are farther from the
120
equator and the sun is thus lower on the horizon.
Chapter 28 Review
2.
3.
4.
Cities such as Seattle and San Francisco are cooler than cities at the
same latitude such as Detroit and Washington. This is because air
from over the cool Pacific Ocean has a cooling effect on the West
Coast cities.
Cities in desert regions such as Tuscon have large temperature
changes. Areas near bodies of water or marshland, such as Seattle or
Tampa, have smaller changes in temperature. This is due to the high
specific heat of water.
Answers are:
a.
4,187 joules
1 hour
350 Calories × ----------------------------- × ---------------------------------- = 407 watts for each student
Calories
3,600 seconds
b.
5.
If there are 30 students, the total amount of power is 30 × 407
watts = 12,200 watts. If a space heater generates 500 watts, then
12,200 watts ÷ 500 watts per space heater = 24 space heaters.
Dancing generates as much heat as 24 space heaters.
6.
(4,000 J ÷ 1,000 J) × 100 = 25%
The efficiency of the machine is 25%.
7.
4,000 J - 1,000 J = 3,000 J of energy lost as heat.
8.
Although some energy is lost as heat, the machine may allow you to
lift a heavy load with a small amount of force.
9.
Overall, hydropower is the least expensive power to generate at less
than 2 cents per kilowatt-hour. Fossil fuels and nuclear power are
roughly comparable in price (3 cents per kilowatt-hour). However, for
fossil fuels, the costs are mainly for the fuel, and in nuclear power the
costs are mainly for operational costs. It should be noted that the cost
of constructing a nuclear plant is about four times more expensive
than a fossil fuel plant and five times more expensive than a
hydropower plant.
10. Answers may vary depending on the research your students have
done. Possible answers should include hydropower, solar power, and
geothermal power but not fossil fuels.
Students need to know that 1 W = 1 J/sec. The calculation is:
4,187 joules
1 hour
100 Calories × ----------------------------- × ---------------------------------- = 116 watts
Calories
3,600 seconds
121
Chapter 28 Review
1.
The planet with the warmest surface temperature is Hydro because it
has the most carbon dioxide in its atmosphere. Carbon dioxide is a
significant global warming gas. As an atmospheric gas, it traps heat
and raises surface temperature.
2.
Before getting started, photocopy a food label and go over it with
your class. Point out that the Calories for a certain food correspond
to a certain amount of that food. As a class, you might want to work
out the Calories for a normal meal.
As an extended activity, you might want to have your students
compare their daily diets with the food pyramid. Do they eat enough
fruits and vegetables? Is the amount of sweets and junk food they eat
in the “tip” or the “middle” of the pyramid?
122
3.
Before having students figure out how many Calories they need,
have them discuss why factors such as height, age, sex, health, and
fitness level might influence the outcome. Additionally, you might
want to have them predict how many Calories they need before
doing the calculation.
Teaching Tools
This section contains helpful teaching tools and information.
Contents
Teaching Tools
Safety ............................................................................................... 124
CPO Science Skill Sheet on Safety ..................................................... 125
CPO Science Safety Contract ............................................................. 127
CPO Science Safety Quiz ................................................................... 128
Evaluating Student Investigations ...................................................... 129
Materials Management ....................................................................... 131
Additional Materials .......................................................................... 132
Lab Report Format ............................................................................ 138
Poster Presentation ............................................................................ 139
International System of Measurements (SI) ........................................ 140
Metric Prefixes .................................................................................. 141
SI Base Units .................................................................................... 142
Graphing ........................................................................................... 144
Formulas ........................................................................................... 148
Physical Constants ............................................................................. 151
Conversion Factors (Dimensional Analysis) ....................................... 152
Spanish Glossary ............................................................................... 151
123
Teaching Tools
Safety
In scientific investigations, you often work with equipment and supplies. These are fun to use, especially because they help you make
discoveries. However, using equipment and carrying out certain procedures in an investigation always require safety. Safety is a very an
important part of doing science. The purpose of learning and discussing safety in the lab is to help you learn how to protect yourself and
others at all times.
The Investigations that you will be doing as part of the CPO Science Program are designed to reduce safety concerns in the laboratory. The
physics Investigations use stable equipment that is easy to operate. The chemistry Investigations use household supplies and chemicals.
Although these chemicals might be familiar to you, they still must be used safely.
You will be introduced to safety by completing a skill sheet to help you observe the safety aids and important information in your science
laboratory. In addition to this skill sheet, you may be asked to check your safety understanding and complete a safety contract. Your teacher
will decide what is appropriate for your class.
Throughout the Investigation Guide, safety icons and words and phrases like “caution” and “safety tip” are used to highlight important
safety information. Read the description of each icon carefully and look out for them when reading your Student Edition and Investigation
Guide.
Use extreme caution: Follow all instructions carefully to avoid injury to yourself or others.
Electrical hazard: Follow all instructions carefully while using electrical components to avoid injury to yourself
or others.
Wear safety goggles: Requires you to protect your eyes from injury.
Wear a lab apron: Requires you to protect your clothing and skin.
Wear gloves: Requires you to protect your hands from injury due to heat or chemicals.
Cleanup: Includes cleaning and putting away reusable equipment and supplies, and disposing of leftover
materials.
Safety in the science lab is the responsibility of everyone! Help create a safe environment in your science lab by following the safety
guidelines from your teacher as well as the guidelines discussed in this document.
124
CPO Science Skill Sheet on Safety
CPO Science Skill Sheet on Safety
Keep this skill sheet in your notebook at all times.
In scientific investigations, you often work with equipment and supplies. These are fun to use, especially because they help you make
discoveries. However, when you use equipment and supplies in a science lab, it is always important to be safe. The purpose of this skill
sheet is to help you learn how to be safe at all times. Safety in the science lab is everyone’s responsibility. You can help create a safe
environment in your science lab by following the safety guidelines on this skill sheet. To help you remember the guidelines, keep this skill
sheet in your notebook at all times.
A. Safety icons in the Investigations
These safety icons appear on the Investigation sheets. Descriptions are written next to each icon.
Work together/teamwork
Thermal hazard
Danger!
Wear your goggles
Electrical hazard
Clean up
Wear protective clothing
B. Safety Guidelines
Read these safety guidelines before each Investigation.
1 Always prepare for each Investigation.
a. Read the Investigation sheets carefully.
b. Take special note of safety instructions.
2 Pay close attention to your teacher's instructions before, during and after the Investigation. Take notes to help you remember what your
teacher has said. Special safety instructions from your teacher will include information about:
a. Working with hot items or solutions.
b. Working with electrical components.
c. How to use your equipment and supplies.
d. How to dispose of chemicals and trash.
3 If the Investigation requires protective devices or clothing (goggles, a lab apron and gloves), gather these at the beginning of the
Investigation.
4 During investigations, emphasize teamwork. Help each other. Watch out for each other's safety.
5 Always clean up after an Investigation. Your teacher will give you special instructions for disposing of your materials.
125
Teaching Tools
C. Special instructions about safety topics
1 Thermal hazards.
a. Always carry or hold hot items with a hot pad. Never use your bare hands.
b. Move carefully when you are near hot items or solutions. Sudden movements could cause you to burn yourself by touching or
spilling something hot.
c. Inform others if they are near hot items or liquids.
2 Electrical hazards.
a. Always keep electrical components away from water.
b. Avoid creating a short circuit with electrical components. Short circuits could cause the components to heat up or spark.
c. Remove metal accessories (watches and jewelry) when working with electrical components.
3 Disposal of materials and supplies.
a. Generally, liquid household chemicals can be poured into a sink. Completely wash the chemical down the drain with plenty of
water.
b. Generally, solid household chemicals can be placed in a trash can.
c. Any liquids or solids that should not be poured down the sink or placed in the trash have special disposal instructions. Follow your
teacher's instructions. Special disposal instructions can be found on the Materials Safety Data Sheet for a chemical.
d. If an item breaks, do not use your bare hands to pick up the pieces. Use a dustpan and a brush to clean up. “Sharps” trash (trash that
has pieces of glass) should be well labeled. The best way to throw away broken glass is to seal it in a labeled cardboard box.
4 What to do in case of danger or an emergency:
a. If you are concerned about your safety or safety of others, talk to your teacher immediately. Examples of times to talk to your
teacher immediately include:
• You smell chemical or gas fumes. This might indicate a chemical or gas leak.
• You smell something burning.
• You injure yourself or see someone else who is injured.
• You are having trouble using your equipment.
• You don't understand the instructions for the Investigation.
b. Listen carefully to your teacher's instructions.
c. Follow your teacher's instructions.
d. Be careful and safe as you follow your teacher's instructions.
126
CPO Science Safety Contract
CPO Science Safety Contract
Keep this Safety Contract in your notebook at all times.
By signing this Safety Contract, you agree to follow all the steps necessary to be safe in your science class and lab. By signing the contract,
you have also agreed to make being safe and following safe practices important.
When everyone understands safety and agrees to be safe by signing this Safety Contract, everyone is more assured of a safe environment.
I, ____________________, (Your name)
; Have read the safety guidelines on the Safety Skill Sheet.
; Understand the safety information presented.
; Will ask questions when I don't understand safety instructions.
; Pledge to follow all of the safety guidelines that are presented on the Safety Skill Sheet at all times.
; Pledge to follow all of the safety guidelines that are presented on Investigation sheets for every Investigation.
; Will always follow the safety instructions that my teacher provides.
Additionally, I pledge to be careful about my own safety and to help others be safe. I understand that I am responsible for helping to create
a safe environment in the classroom and lab.
Signed and dated,
____________________
127
Teaching Tools
Name: ____________________
CPO Science Safety Quiz
A. Knowing your science lab
1. Draw a diagram of your science lab on a separate piece of paper. Include in your diagram the following items:
Exit/entrance ways
Fire extinguisher(s)
Eye wash and shower
Location of eye goggles and lab aprons
Location of special safety instructions
Sink
(example: bulletin board, chalk board, etc.)
Fire blanket
First aid kit
Trash cans
2. Include notes on your diagram that explain how to use these important safety items.
B. Quiz
1. How many fire extinguishers are in your science lab?
2. List the steps that your teacher and your class would take to safely exit the science lab and the building in case of a fire.
3. Before beginning certain Investigations, why should you put on protective goggles and clothing first?
4. Why is teamwork important when you are working in a science lab?
5. Why should you always clean up after every Investigation?
6. List at least three things you should you do if you sense danger or see an emergency in your classroom or lab?
7. Five lab situations are described below. What would you do in each situation? Explain how you would be careful and safe in each
situation.
a. You accidentally knock over a beaker and it breaks on the floor.
b. You accidentally spill a large amount of water on the floor.
c. You suddenly you begin to smell a “chemical” odor that gives you a headache.
d. You hear the fire alarm sound while you are working in the lab. You are wearing your goggles and lab apron.
e. While your lab partner had her lab goggles off, she gets some liquid from the experiment in her eye.
f. A fire starts in the lab.
128
Evaluating Student Investigations
Evaluating Student Investigations
1. Did the student follow the Investigation procedures?
2. Did the student follow the safety guidelines and care for materials properly?
3. Did the student take responsibility for lab clean up?
4. Did the student participate in class discussion?
5. Did the student demonstrate appropriate skills in areas such as:
• accurate measurement
• data collection
• graphing
6. Can the student answer the key question from the Investigation either in writing, through verbal explanation, or by visuals?
7. Did the student ask questions and/or apply his or her knowledge?
8. Did the student work effectively with other group members?
9. Can the student repeat the Investigation with greater facility and demonstrate the procedures in a more knowledgeable manner?
10. Can the student reflect about something that surprised or interested them, or something that they learned?
129
Teaching Tools
Student Investigation Evaluation Form
1. What is one interesting observation you made during the Investigation, or one thing that surprised you?
2. What is one thing that you learned?
3. Why is the information you learned important to your studies, your life, or to others?
4. What questions do you have after completing this Investigation? What would you like to know about?
5. How would you explain this Investigation to someone else through writing, a conversation, or with a drawing?
130
Materials Management
Materials Management
Managing all of the necessary equipment and supplies is a time-consuming task for teachers of any laboratory-based science, but it can
seem especially daunting in an inquiry-based classroom, where the lab is used not only to demonstrate selected ideas from text, but to
present each important concept in the curriculum. Streamlining materials management at the beginning of the school year can save
countless hours and minimize that frazzled feeling that comes from being overwhelmed with “too much stuff.”
Here are some practical tips for organizing your laboratory space:
Assemble kits of supplies needed for each unit. Label each kit and all of its components with a number. Yard-sale stickers, which can be
purchased at office supply stores, work well for this purpose. Even small items can be numbered. Although this task may seem tedious, it
does save time in the long run.
Require students to write their kit number on their investigation sheet. This sense of “ownership” of the materials often increases students'
sense of responsibility for the materials. It provides a means of holding students accountable for lost gears, improperly cleaned beakers, and
the like.
Kits can be assigned to a group for one lab period, or for an entire unit. Students often take better care of materials that they know they will
be using again.
Open top plastic “milk crates” that hold hanging files can be purchased inexpensively at office supply stores. Set up a crate for each class
with a file for each student. These can be used to help students keep track of investigation sheets that will be used for more than one class
period. They can also be used as mailboxes to return papers to students in a manner that respects students' privacy.
When storing items, think ergonomically. While hazardous materials must be stored in locked cabinets, for all other items think about ease
of access. If you have open shelving, store frequently used items between waist and shoulder height. Lightweight seldomly-used items
should go on high shelves; heavy ones at the bottom. Don't stack different types of materials on top of one another or layer different items
two or three deep—they won't stay that way! Instead, install simple shelf dividers and “lazy susan” spinners, which can be purchased
inexpensively in kitchen supply stores or home improvement shops.
Clear plastic containers with lids work wonders for corralling easily misplaced items such as paper clips, scissors, pencils, and rolls of tape.
Enlist student help with materials management. A science club could put together kits of materials as a service project. Ask a student who
has taken away from the classroom experience through disruptive behavior to “give something back” to the classroom by spending a free
period organizing shelves, cleaning glassware, etc. Then use that time to connect with the student—disruptive students sometimes just need
some one-on-one attention from an adult. Working side-by-side provides an opportunity to reestablish a positive relationship.
131
Teaching Tools
Additional Materials
The following pages list materials used in the Investigations in addition to the kits provided. For ease of ordering and buying, the list is
divided into the following subsections: office, household, and hardware supplies; laboratory equipment and science educational supplies;
household chemicals; and specialty items. Quantities shown are the amounts needed for a class of 30 students. Consumable materials are
indicated. Perishable, non-commercial, demonstration and optional items are not included in the list.
If you have concerns about the use or handling of chemicals, contact the manufacturer of the product with your questions and request a
materials safety data sheet (MSDS) for the product. A phone number for the manufacturer is usually listed on the product label.
Investigations that use these chemicals should be completed carefully, with safety in mind. Keep the volumes of liquids or powders that
students use to a minimum and in small containers. Discuss safety concerns before each Investigation and continue to remind your students
to be safe and careful throughout the Investigation. Have cleanup materials such as paper towels, sponges, and plastic trash bags (to collect
paper towels with strong smelling chemicals) on hand for spills. Students should always wash their hands after any lab that uses chemicals.
Office, household, and hardware supplies
baking pans, 12 x 18 inches
balloons
batteries, D size
carbon paper
chalk
clipboards
coffee filters
coffee stirrers or craft sticks
cups, 3-ounce wax-coated paper
cups, 8-ounce Styrofoam
dishpans
glue sticks
hex nut and bolt sets, at least 2 inches long
hex nuts, brass, large
hex nuts, brass, medium
hex nuts, brass, small
132
Quantity
6
12
30
15 sheets
18 pieces
6
6
90
50
50
6
6
60
6
6
6
Consumable
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Office, household, and hardware supplies
hex nuts, steel, large
hex nuts, steel, medium
hex nuts, steel, small
light bulbs and sockets, 100-watt
markers, overhead projector, assorted colors
markers, permanent, assorted colors
nails, very thin
nails, galvanized, 7 cm in length
paper clips, large
paper clips, small
paper, large black construction
paper, easel or newsprint
pencils, colored
plastic bags, sealing, sandwich size (freezer type works best)
plastic bags, sealing, quart size (freezer type works best)
plastic bags, sealing, gallon size (freezer type works best)
plastic wrap
rubber bands, thick
sandpaper
scissors
Scotch™ brand magic tape
sponges
straws, flexible
straws, regular
string, elastic
towelettes, moist
trash bags, tall kitchen
wax paper
wooden matches (preferably long)
Quantity
6
6
6
6 sets
10 sets
8 sets
6
10
20
1000
18 sheets
50 sheets
15 sets
400
60
60
1 large box
50
10 sheets
12 pairs
6 small rolls
6
50
100
30 meters
120
6
1 large box
1 large box
Consumable
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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Teaching Tools
Laboratory and science educational supplies
balances, digital, accurate to a 0.1 gram
beakers, 1000-milliliter, glass, heat resistant
beakers, 400-milliliter
beakers, 250-milliliter, glass, heat resistant
beakers, 150-milliliter (CHECK)
beakers, 100-milliliter (marked at the 50-milliliter level)
Bunsen burner grating, iron
chromatography paper, 10-by-3-centimeter strips
clay, modeling
culture vials, 100-milliliter
Daphnia (water flea) cultures and culture equipment
electrical meters, DC
flask, Erlenmeyer, with 2-hole rubber stopper and glass tubing
glass jars with lids (minimum capacity 300 milliliters) household?
goggles
graduated cylinder, 100-milliliter, with a removable base
graph paper, 8.5 by 11 inches
graph paper, 11 by 17 inches
iron filings
lab coats or aprons
litmus paper, blue
litmus paper, red
magnets, bar
meter sticks
mortar and pestle
nitric acid, 1 M
pH paper or pH color indicator tablets, wide-range
pipettes, plastic
pipettes, wide-bore
134
Quantity
8
6
18
48
10
18
6
30 strips
60 sticks
100
100 fleas
10
6
18
30
12
320 pieces
36 sheets
4 ounces
30
72 pieces
72 pieces
30
6
6
500 ml
15 pieces
36
30
Consumable
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Laboratory and science educational supplies
protractors
reaction plates, 8-well strips
rulers, metric/English, clear
screens, wire or nylon, of different size mesh
stirring rods
tape measures
test tubes, small, with stoppers (CHECK)
test tubes, 50-milliliter (CHECK)
thermometer, digital
thermometer, Celsius
thermometer, Fahrenheit
water quality testing sampling containers; containers to be used for
the tests listed belowa
water quality (tapwater) test for chlorine
water quality (tapwater) test for copper
water quality (tapwater) test for lead
water quality (tapwater) test for pH
water quality (tapwater) test for water hardness
water quality (surface water) test for coliform bacteria
water quality (surface water) test for dissolved oxygen
water quality (surface water) test for biological oxygen demand
(BOD)
water quality (surface water) test for nitrate
water quality (surface water) test for pH
water quality (surface water) test for phosphate
water quality (surface water) test for temperature
water quality (surface water) test for turbidity
wire, magnetic, 24 gauge
Quantity
15
12
6
6 of each size
6
6
24
60
6
6
6
350
60
60
60
60
60
6
6
6
Consumable
Yes
Yes
6
6
6
6
6
30 meters
a.The containers and all or some of the tests for water quality testing may be available as classroom kits in some catalogs
135
Teaching Tools
Household chemicals
ammonia (ammonium hydroxide), no detergent additive
baking soda (sodium bicarbonate)
charcoal-activated heat packs
cold packs (ammonium nitrate)
corn oil
corn starch
drain cleaner (sodium hydroxide)
effervescent antacid or cold medicine tablets
Epsom salts (magnesium sulfate)
food coloring, assorted colors
gelatin, plain
glycerin, available in drug stores
hydrogen peroxide
light corn syrup
molasses
rubbing alcohol (isopropyl alcohol)
seltzer
shampoo, clear
snow melt (calcium chloride), in ice melting products
sugar cubes
sugar, granulated
salt (sodium chloride), rock
salt (sodium chloride), table
trisodium phosphate, available in hardware stores
vinegar (5% acetic acid)
water, distilled
water, spring
136
Quantity
600 mL
120 g
6
180 g
850 mL
15 g
50 g
12
130 g
1 bottle of each
15 g
600 mL
1.2 L
600 mL
300 mL
2L
7L
300 mL
210 g
60
60 g
150 g
100 g
50 g
1.5 L
5L
7L
Consumable
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Specialty items
ACEEE's Green Book™: The Environmental Guide to Cars and
Trucks (purchase at www.aceee.org or call 202-429-0063)
blocks, wood or plastic, 5.5 inches long
glass bottles, cylindrical base (e.g., root beer bottles)
glow sticks
glue guns
hot melt glue
immersion heaters
laminated graph paper that fits inside the 12 by 18 inch baking pans
matchboxes, large
pennies, minted after 1962
photo luminescent sheets
sand, dark (or dirt)
sand, light-colored
Slinky™ spring toys
springs
tuning forks
wine glasses
wire, aluminum, 28-gauge
wire, copper, 28-gauge
Quantity
6
12
24
6
6
6 sticks
6
6
6
600
15
1.2 L
1.2 L
6
6
6 of different
frequencies
24
45 meters
45 meters
Consumable
Yes
137
Teaching Tools
Lab Report Format
What is a lab report?
A lab report is an explanation of your findings from an investigation. If your lab report is written clearly, anyone who reads your lab report
will be able to understand what you were trying to learn. They will see why and how you performed your experiment.
When you tell a reader how to repeat your experiment, you are giving another person the tools to evaluate your work. It they can get data
that is similar to yours and come to similar conclusions, then you have support for your ideas.
Because Sir Isaac Newton’s findings from his experiments were repeatable, what started out as ideas are now scientific laws! For example,
Newton’s thoughts about a falling apple led to the law of universal gravitation. This law is an equation that explains why the moon and each
of us experiment gravitational attraction to the Earth. Wow!
What are the parts of a lab report?
On a cover sheet or at the top of your report include your name, the title of the lab, the date of completion, and your lab partners’ names.
The main parts of the lab report are listed below along with a description of each part.
• Research question: What are you trying to find out through this experiment?
• Introduction: This paragraph describes the topic you are studying and how it relates to your experiment. State your hypothesis at the
end of the introduction.
• Procedure: This paragraph is a description of the experiment you performed to test your hypothesis. You may wish to include a
sketch of the apparatus you used. Be sure to name the experimental variable and list the variables that you controlled in the
experiment.
• Results: In this paragraph, you describe your data. Often you will include a graph. Write a short description of the data, but do not
draw any conclusions in this paragraph.
• Conclusions: Your conclusions about your experiment are described in this part of the lab report. The conclusions paragraph
describes what happened in your experiment, and whether or not your hypothesis was correct.
138
Poster Presentation
Poster Presentation
A poster presentation is a visual representation of your lab report. This is a public display of your investigation findings. The poster should
include the seven categories mentioned below. Each section should be labeled on a separate piece of paper. Your poster should be readable
from a comfortable distance away (2-3 feet). You should use size 18-20 fonts at a minimum for your text. In addition, your poster should be
eye-catching, organized, and clear.
Title: The title should be visible from a distance. The title should quickly communicate the ideas of your investigation and attract an
audience to your poster.
Abstract: This page should include a three to four sentence summary of key ideas, results, and conclusions. An additional sentence should
provide the reason for your investigation. You should consider this section an advertisement. After someone reads your abstract, they
should be inspired to read your entire poster. The abstract should be printed double-spaced in size 20-22 font.
Introduction: This is background information necessary to understand the scientific principle(s) being investigated. A reader unfamiliar
with the subject should be able to understand all aspects of your poster after reading the introduction. This includes what principle is being
investigated, why it is interesting, and other principles on which it is based. This section should be concise but thorough, and only one to
three pages long. The introduction should be printed double-spaced in size 18-20 font. You will need to introduce formulas and define
concepts in this section.
Procedure: This page is a brief description of all methods and tools utilized. Do not simply copy the instructions from your investigation
guide. Include everything you did while completing the experiment. This page can be printed single or double space in size 18-20 fonts and
should include appropriate diagrams and pictures.
Results & Analysis: This should be a discussion of your results and how they relate to the scientific principle being investigated. You
should include any charts or graphs of your data. This section should connect the ideas of the introduction, procedure, and results. Account
for the source of any errors encountered during the lab including any differences between your values and known literature values. The
analysis should be single or double-spaced and size 18-20 font.
Conclusion: This should be a one to four sentence description of what has been proven or demonstrated by your results. Ideas for further
investigation or personal scientific reflections (not subjective feelings as to whether this was a good lab or bad lab) should be found here.
The conclusion should be double spaced and size 18-20 font.
Reference: References should be found here if needed. References should be size 16-18 font.
139
Teaching Tools
International System of Measurements (SI)
In ancient times, as trade developed between cities and nations, units of measurements were developed to measure the size of items bought
and sold in various transactions. Greeks and Egyptians based their measurements of length on the human foot. Usually it was based on the
king’s foot size. Volume was measured determined by how much goatskin a basket could hold. Why do you think this method was not
accurate?
During the Renaissance, as scientists began to develop the ideas of physics and chemistry, they needed better units of measurements in
order to communicate scientific data more efficiently. Scientists such as Kepler, Galileo, and Newton needed to prove their ideas with data
based on measurements that other scientists could reproduce.
In March 30, 1791 in Sevres, France, the French Academy of Sciences proposed a system that would be simple and consistent. The French
scientists based the units of length on a fraction of the distance between the Earth’s equator and the North Pole along a line passing through
Paris. The system’s basic unit was called a meter after the Greek word metron that means, “measure.” The liter was defined as the new
standard for volume. One milliliter was equal to the volume of one cubic centimeter. The gram was defined as the new standard for mass.
The gram was defined as the mass of one milliliter of water.
The United States made the decision to adopt the metric system in 1884. The decision was made as part of a political agreement to move the
Prime Meridian from El Hierro Island in Spain to Greenwich, England. However, the adoption process has been very slow. Most
Americans still use the English System (feet, inches, and pounds). Since 1992, all U.S. Government agencies have been required to use the
metric system in business transactions.
You may think that only scientists use the metric system, but the majority of people in the world use the metric (or Standard International)
system of measurements in their daily lives. If you travel overseas, you will find that a car’s speed is measured in kilometers per hour. At
the gas station, gasoline is sold in liters. The amount of food is measured in grams. The energy for nutritional information on the label for
food is measured in joules (as opposed to Calories).
The Standard International (SI) system is particularly attractive and easy to use because all the units in the SI system are based on factors of
10. In the English system, there are 12 inches in a foot, 3 feet in a yard, and 1760 yards in a mile. By contrast, in the SI system, there are
10 millimeters in a centimeter, 100 centimeters in a meter, and 1000 meters in a kilometer. The prefixes in the SI system indicate the
multiplication factor to be used with the basic unit. For example, the prefix kilo- is for a factor of 1000. A kilometer is equal to 1000
meters and a kilogram is equal to 1000 grams.
140
Metric Prefixes
Metric Prefixes
Prefix
Symbol
Factor of Base Unit
pico
p
0.000 000 000 001
=
10-12
nano
n
0.000 000 001
=
10-9
micro
µ
0.000 001
=
10-6
milli
m
0.001
=
10-3
centi
c
0.01
=
10-2
deci
d
0.1
=
10-1
deka
da
10
=
101
hecto
h
100
=
102
kilo
k
1 000
=
103
mega
M
1 000 000
=
106
giga
G
1 000 000 000
=
109
tera
T
1 000 000 000 000
=
1012
141
Teaching Tools
SI Base Units
Length: A distance from one point to another.
1 kilometer (km)
=
1 000 m
1 meter (m)
=
SI base unit of length
1 centimeter (cm)
=
0.01 m
1 millimeter (mm)
=
0.001 m
1 micrometer (µm)
=
0.000 001 m
1 nanometer (nm)
=
0.000 000 001 m
1 picometer (pm)
=
0.000 000 000 001 m
1 kilogram (kg)
=
SI base unit of mass
1000 grams (g)
=
1 kg
1 milligram (mg)
=
0.000 001 kg
1 microgram (µg)
=
0.000 000 001 kg
Mass: The amount of matter of an object.
142
SI Base Units
Volume: The amount of space an object occupies.
1 liter (L)
=
Common unit for liquid volume
1 liter (L)
=
1000 cubic centimeters
1 cubic meter (m3)
=
1000 L
1 kiloliter (kL)
=
1000 L
1 milliliter (mL)
=
0.001 L
1000 mL
=
1L
1 milliliter (mL)
=
1 cubic centimeter (cm3)
Temperature: The measurement used to quantify the sensations of hot and cold.
Celsius (°C)
100°C
=
Boiling point of water
0°C
=
Freezing point of water
Unit Conversion: These two equations can be used to convert from degrees Fahrenheit to degrees Celsius and vice versa.
5
°C = (° F − 32)
9
9
° F = (°C ) + 32
5
143
Teaching Tools
Graphing
Line Graphs
When do you use a line graph?
Line graphs are used to show the relationship between two variables. The data collected is usually in the
form of two columns of numbers. Each pair of numbers represents a data point. After the data points are
plotted on the graph, a line is drawn through the points (the data points are not connected “dot-to-dot”). The
line shows the trend of one variable as the other variable changes so that you can make predictions about the
data.
What is a line graph?
Graph A is a line graph. Line graphs are “pictures” of two sets of information gathered during an experiment.
The first set of information in graph A is “distance you can travel.” The second set of information is “amount
of gas.” Both sets of information, “distance you can travel” and “amount of gas,” are variables. One of the
variables on a line graph (“amount of gas” in the example) can be changed by the experimenter. A variable
that changes based on the decisions of the experimenter is called the independent variable. The second
variable (“distance traveled”) changes in response to the other variable. This variable is called the dependent variable.
The horizontal edge of a graph is called the x-axis. The vertical edge is called the y-axis. The independent
variable is plotted from the x-axis and the dependent variable is plotted from the y-axis. The tiny lines
along each axis are called tick marks. The tick marks on the x-axis on graph A are placed at intervals of 5.
The intervals on the y-axis are every 100. When deciding how to place the tick marks on your graph, first
figure out the range of your data. When making a graph, be sure to fill up all of the space available.
To help others understand a graph you make, always title the graph and label the x- and y- axes. When
making the title, write the name of the dependent variable first followed by the name of the independent
variable. The word “versus” (or its abbreviation, “vs.”) goes between the names for the variables. When
making the labels for each axis, write the units for each variable in parentheses.
Line graphs have data points. A data point includes the x-value for the independent variable and the
corresponding y-value for the dependent variable.
144
Graphing
Graphing (continued)
Graph B is a copy of graph A with two data points highlighted: (5, 125) and (10, 250). A line is drawn through the data points in graph A
(and B). This is because the data values for a line graph are continuous. The line between data points allows you to predict how far you can
travel if you have an amount of gas that you didn’t test. For example, from graph A or B, you could find out how far you can travel with
15.5 gallons of gas, even through there are only data points for 15 and 16 gallons of gas.
The trend for the data in graph A is a straight line with a positive slope. This means that as the x-values increase, the y-values also increase.
If the y-values decreased as the x-values increased, the line would point downward and have a negative slope.
The slope of a line graph tells you the rate of change for the variables. For example, slope can be found by dividing the vertical change by
the horizontal change for a line.
vertical change slope = ------------------------------------------horizontalchange
For graph B, the vertical change is: 250 - 125 = 125. The horizontal change is: 10 - 5 = 5. Using the formula above, the rate of change
would be 125 ÷ 5 = 25. In other words, the slope of this graph is 25. In terms of the data in graph A, the slope is gas mileage. The gas
mileage for the car in graph A is 25 miles per gallon.
y2 – y1
– 125 = 125
slope = --------------= 250
------------------------------ = 25
x2 – x1
10 – 5
5
You can also find the slope using the equation for a line: y = mx + b, where b is the point in the line that crosses the y-axis. This point is
also called the y-intercept. In graph B, the y-intercept is (0,0). When zero gas is in the car, the car will not be able to travel any distance.
The x and y represent data point values, and m represents the slope of the line.
145
Teaching Tools
Bar Graphs
When do you use a bar graph?
Bar graphs (or histograms) are used to show how categories of information compare to each other. The data
collected consists of values (i.e., numbers or percentages) that correspond to the categories. The value for
each category is represented as the height of a bar on the graph. A category with a high value will have a
taller bar than a category with a lower value.
What is a bar graph?
Graph C is an example of a bar graph, also known as a histogram. Unlike line graphs, bar graphs compare
data values that do not change continuously.
In a bar graph, one set of data is divided into categories, events or places. For graph C, each bar represents a
place you might travel to from home. To set up a bar graph, you need an x-axis and y-axis. The categories are
listed along the x-axis. The range of values for the dependent variable (“distance from home” in this case)
placed on the y-axis. The data is plotted by drawing bars on the x-axis. The height of the bars is based on
their y-value. For example, the bar corresponding for grandma’s house is much taller than the rest because
her house is 30 miles away. The other places visited on a weekly basis are 5 or 10 miles away from home.
Like line graphs, bar graphs should have a title and labels on each axis. Units are included in parentheses for the dependent variable on the
y-axis.
146
Graphing
Pie Graphs
When do you use a pie graph?
Pie graphs are circular graphs that are used to show how categories of information compare to each other. The data collected consists of
percentages that correspond to the categories. The sum of the categories represent a whole. For example, a set of categories might represent
all the activities that you do during one weekday. Each category on a pie graph is represented by a section of the “pie”.
What is a pie graph?
Graph D is a pie graph that shows how a student might spend 24 hours during a school week. Some days
a student might be so tired that he or she would like to sleep for 24 hours straight. If this were the case,
the category, “sleeping,” would represent 100% of the “pie.” In reality, a student sleeps for part of each
day. The ways that a student might spend the rest of the time are represented with different sections of
the pie graph.
Like a bar graph, pie graphs show values for categories of information. In order to make a pie graph, you
need to find out how much of the pie each category should represent. Each category is a percentage of
the pie represented by a section or “slice” of the pie graph. In pie graphs, the sections are labeled and the
graph has an informative title.
To figure out the percentages for each category, divide the quantity for the category by the total number
of parts available. For graph D, the whole is equal to 24 hours. If you sleep 8 hours a night, that’s 33% of
the whole 24 hours.
quantity for the category
8 hours
category percentage = ------------------------------------------------------------ × 100 = -------------------- × 100 = 0.33 × 100 = 33 %
total parts
24 hours
To find the measure of each angle for each section of the pie graph, you multiply the percentage for the category by 360, which is the
number of degrees in a circle. To graph this data, you need a compass to make a circle and a protractor to measure and draw the angle that
represents the percentage for a section. For example, the percentage for the sleep section is 33%. The angle for this section is 118o (0.33 x
360 = 118o). If you only sleep 6 hours a night, what would the angle for the sleep section be? Six hours is 25% of the pie, so the angle
would be a right angle (0.25 x 360 = 90o).
angle of section = 0.33 × 360 degrees = 118 degrees
147
Teaching Tools
Formulas
Force and Motion
Acceleration
Mechanical
advantage
Momentum
Newton’s Second
Law
Slope of a line
vf – v i
a = ------------t
Fo
MA = -----F
i
P = mv
F
a = ---m
y2 – y1
slope = --------------x2 – x1
vf is final speed in meters/second.
vi is initial speed in meters/second.
t is time in seconds.
MA is mechanical advantage.
FO is output force.
Fi is input force.
P is momentum in kilogram-meter/second.
m is mass in kilograms.
v is velocity in meters/second.
a is acceleration in meters/second2.
F is force in newtons.
The slope of a line is calculated using two points on
that line: (x1, y1) and (x2, y2).
Speed
d
v = --t
v is average speed in meters/second.
d is distance traveled in meters.
t is the time taken to travel that distance in seconds.
Weight
F w = mg
Fw is the weight force in newtons.
g is the acceleration of gravity (9.8 meters/second2).
148
Formulas
Work and Energy
Work
W = Fd
Power
Kinetic energy
Potential energy
P = ---t
P is power in watts.
W is work in joules.
t is time in seconds.
2
= 1
--- mv
k
2
Ek is kinetic energy in joules.
v is speed in meters /second.
W
E
W is work in joules.
F is force in newtons.
d is distance in meters.
E p = mgh
Ep is potential energy in joules.
g is the acceleration of gravity (9.8 meters/second2).
h is height in meters.
Electricity
Ohm’s law
Power
V
I = ---R
P = V
×I
I is current in amps.
V is voltage in volts.
R is resistance in ohms.
P is power in watts.
V is voltage in volts.
I is current in amps.
Sound and Waves
Frequency
1
f = -T
f is frequency in hertz.
T is period in seconds.
Period
1
T = f
T is period in seconds.
Wave speed
v = fλ
v is speed in meters/second.
λ is wavelength in meters.
149
Teaching Tools
Light
Index of
refraction
speed of light in air
n = ---------------------------------------------v
n is the index of refraction.
The speed of light in air is 300 x 106 meters/second.
v is the speed in the material in meters/second.
Properties of Matter
Density
m
D = ---v
D is density in grams / cubic centimeter.
m is mass in grams.
v is volume in cubic centimeters.
Heat
Q = mc∆T
Heat gain
150
Q is heat gained or lost in calories.
m is mass in grams.
c is specific heat for a substance in
calories/grams °C.
∆T is change in temperature in °C.
Physical Constants
p
Forces and Motion
q
Standard acceleration of gravity
Newtonian constant of gravitation
y
g
G
meter / kilogram / second
-1 -2
m kg s
3
kg
kilograms
kg
kilograms
7.36 x 10
22
kg
kilograms
1.50 x 1011
m
meters
3.8 x 10
3.84 x 108
m
meters
J
4.2 x 103
4.185 x 103
J kcal-1
e
1.6 x 10-19
1.602176462 x 10-19
C
cs
343
343
m s-1
meters / second
c
h
300,000,000
299,792,458
m s-1
meter / second
6.6 x 10-34
6.62606876 x 10-34
Js
Joules-second
1.6 x 10-27
1.67262158 x 10
kg
kilogram
-27
1.6 x 10
1.67492716 x 10
kg
kilogram
Mass of an electron
mp
mn
me
9.1 x 10-31
9.10938188 x 10-31
kg
kilogram
Avogadro's number
NA
6.022 x 10-23
6.02214199 x 1023
mol-1
per mole
5.98 x 10
Mass of moon
Astronomical unit (average earthsun distance)
7.4 x 1022
1.50 x 1011
Mechanical equivalent of heat
Speed of sound (20 C, 1
atmosphere)
Speed of light in a vacuum
Mass of a proton
Molar mass of carbon-12
Water and Solutions
meter / second2
3
24
6.0 x 10
Mass of a neutron
Changes in Matter
6.673 x 10
Mass of earth
Plank's constant
Properties of Matter
6.7 x 10
-11
m s-2
1.99 x 1030
Electricity and Magnetism Charge of an electron
Light and Optics
-11
24
A.U.
8
Average earth-moon distance
Sound and Waves
9.80665
2.0 x 1030
Mass of sun
Work and Energy
9.8
Standard atmospheric pressure
12
-3
-27
-27
-3
2
Joules / kilocalorie
Coulomb
M ( C)
12 x 10
12 x 10
kg mol-1
Ps
101,000
101,325
Pa
kilogram per mole
Pascal
(1 atmosphere = 1.01 x 105 Pascals)
Heating and Cooling
Boltzmann constant
Absolute zero of temperature
k
0° K
-23
1.4 x 10
-273
-23
1.3806503 x 10
-273.15
-1
JK
°C
Joules / °Kelvin
°Celsius
151
Teaching Tools
Conversion Factors (Dimensional Analysis)
Scientific terminology is like any other language in that there are often many ways to say one thing. For instance, when measuring the
width of a window, you can say that it measures 36 inches long. You can also say it measures one yard in length. Of course, we are not
saying that the actual length of the window has changed—the only thing that has changed is the unit of measure.
In a typical language—English, for example—we can merely substitute one word for another, like saying car instead of automobile. In the
language of science, however, there is always a numeric quantity that is associated with the unit of measure. So in describing something in
science (an object, action, or phenomena), when we want to change from one unit of measure to another, we need to adjust the quantity as
well. For example, when we changed the description of the window’s width from inches to yards, we had to change the quantity from 36 to
1. There is a system we can use to make the change. We can call it dimensional analysis.
Example: If you’re making a cake that needs 12 eggs, you can refer to the 12 eggs as one (1) dozen since 12 items equals a dozen.
Mathematically, we say 12 eggs=1 dozen eggs.
What happens if you take the units out of the expression? You will get 12=1. If you take away the units, the equation is no longer true. Units
are essential in the language of science.
In mathematics, we know this to be true: Any quantity (other than zero) divided into itself always results in one (or unity). That is:
Suppose you have two units that are shown to be equal, like:
When you multiply any quantity by one, the size or degree of that quantity is unchanged.
So you can use the expressions in the parentheses to exchange (or convert) your units. We call these expressions conversion factors.
Example: If you are being offered 10 dozen eggs and you want to know how many individual eggs you will receive, you can use
dimensional analysis to determine the correct number.
Note that a unit that appears in the numerator and denominator is cancelled out.
152
Conversion Factors (Dimensional Analysis)
Also, when choosing which conversion factor to use, we had two options:
We chose the factor with the units (eggs) that we wanted in the numerator.
When converting one unit to another, you need to drop the current unit in favor of another. This is done by canceling out units.
In the example above, we cancel the units “dozen eggs,” but not the quantity associated with it.
More examples:
1
If you drop an egg 72 inches, how many feet is that?
1 foot = 12 inches, so use one of the following factors:
2
How many feet are in 60 miles?
1 mile = 5,280 feet, so use one of the following factors:
153
Teaching Tools
3
How many seconds are in an hour?
1 hour = 3,600 seconds, so use one of the following factors:
4 Suppose you want to exchange one unit of speed for another. You can do it by breaking the problem down into steps.
Say you are in a car traveling 60 miles per hour, and you want to know the distance in feet that you are traveling each second.
We will start by converting your speed from miles-per-hour to feet-per-hour:
Now let's change hours to seconds:
You could also combine all of your conversion factors in one long expression:
In the example here, we wanted to convert seconds to hours.
So why did we use the conversion factor with seconds in the denominator?
The answer is that we want a result that puts seconds in the denominator position, not the numerator (feet per second).
154
A
alternating current / corriente alterna – corriente eléctrica que
invierte su dirección a intervalos regulares. Se abrevia CA.
amperes / amperios – unidad de medida de la corriente
eléctrica. Se abrevia amp.
accelerate/acelerar – aumento de la rapidez o cambio en
dirección.
amplitude / amplitud – el tamaño de un ciclo.
acceleration/aceleración – variación de la rapidez por unidad
de tiempo.
acid/ácido – sustancia química que libera iones hidrógeno, H+,
en una solución.
acid precipitacion/precipitación ácida – lluvia, nieve o neblina
que tiene un pH menor de 5.6.
acid rain/lluvia ácida – lluvia con un pH menor de 5.6.
acoustics/acústica – ciencia y tecnología del sonido.
addition reaction/reacción de adición – reacción en que dos o
más sustancias se combinan para formar un nuevo
compuesto.
air friction/fricción del aire – fuerza que se opone al
movimiento de los cuerpos en el aire.
albedo/albedo – porcentaje de la luz del Sol que refleja la
superficie de un planeta.
alloys/aleaciones – soluciones formadas por dos o más metales.
alpha decay / desintegración alfa – desintegración radiactiva en
que el núcleo de un elemento radiactivo emite partículas
alfa (un núcleo de helio).
alpha particles / partículas alfa – partícula con carga parcial,
emitida por el átomo de un núcleo durante su
desintegración radiactiva. También se conoce como un
núcleo de helio.
anhydrous / anhidro – significa “sin agua” y describe el estado
de un hidrato que ha perdido agua por evaporación.
aquifer / acuífero – área subterránea que tiene rocas y
sedimentos que almacenan agua.
Archimede’s principle / Principio de Arquímedes – establece
que la fuerza ejercida por un cuerpo sobre un líquido es
igual al peso del fluido desplazado por el cuerpo.
atmospheres / atmósferas – unidad de medida de la presión
atmosférica. Se abrevia atm.
Spanish Glossary
absorbers/absorbedores – cuerpos que tienen la capacidad de
absorber energía radiante.
atom / átomo – la partícula más pequeña de un elemento que
puede existir por sí misma o en combinación con otra
partícula.
atomic mass / masa atómica – masa promedio de todos los
isótopos conocidos de un elemento.
atomic mass units / unidades de masa atómica – se define
como la masa de 1/12 de un átomo de carbono-12
(6 protones y 6 neutrones en el núcleo, más 6 electrones
fuera del núcleo).
atomic number / número atómico – número de protones que
tiene un átomo.
Spanish Glossary
155
atomic theory / teoría atómica – teoría que establece que toda
la materia está compuesta por pequeñas partículas llamadas
átomos.
average speed / rapidez promedio – indica la rapidez a la que
se desplaza un cuerpo a través de cierta distancia.
Avogadro's number / número de Avogadro – número de
átomos en la masa atómica de un elemento expresada en
gramos; o el número de moléculas en la fórmula masa de un
compuesto, también expresada en gramos.
B
balance / equilibrar – ocurre cuando el número y el tipo de
átomos es igual en ambos lados de una ecuación.
base / base – sustancia química que libera iones hidroxilo,
OH-, en una solución.
battery / batería – instrumento que utiliza energía química
para producir cargas eléctricas.
beat / compás – alternancia rápida de sonidos y silencios.
beta decay / desintegración beta – desintegración radiactiva en
que el núcleo de un elemento radiactivo emite partículas
beta (electrones).
beta particles / partículas beta – partícula con carga negativa
(un electrón) emitida por el núcleo de un átomo durante su
desintegración radiactiva.
binary compound / compuesto binario – compuesto covalente
formado por dos tipos de elementos.
156
British thermal unit / unidad térmica inglesa (Btu) – cantidad
de calor que se requiere para elevar en 1°F, la temperatura
de una libra de agua. Un Btu equivale a 1,055 julios ó
252 calorías.
britleness / fragilidad – medida de la tendencia de un material
a quebrarse, como resultado de un impacto.
buoyancy / flotabilidad – medida de la fuerza ascendente que un
fluido ejerce sobre un cuerpo.
buoyant convection / convección de flotabilidad – véase
convección natural.
C
calorie / caloría – cantidad de calor que se requiere para elevar
en 1°C la temperatura de un gramo de agua.
carbohydrate / carbohidrato – nutrientes cuyas moléculas
están compuestas por azúcares simples o azúcares
compuestos. Contienen cuatro calorías de energía por
gramo.
carbon dating / datación por carbono-14 – medida de la
cantidad de carbono-14 que contiene una muestra con una
antigüedad que varía entre algunos miles de años y
50,000 años.
cause and effect / causa y efecto – relación entre el evento que
origina un proceso y lo que resulta debido al proceso.
Celsius scale / escala Celsius – escala de temperatura en que el
cero equivale a la temperatura de congelación del agua
(0°C) y 100 equivale a la temperatura a la cual hierve el
agua (100°C). C significa Celsius.
chemical bonds / enlaces químicos – unión entre dos o más
átomos diferentes debido a su atracción mutua.
chemical energy / energía química – tipo de energía
almacenada en las moléculas.
coefficient / coeficiente – número que se escribe en frente de
las fórmulas químicas para igualar el número de átomos en
ambos lados de una ecuación.
chemical equations / ecuaciones químicas – fórmulas y
símbolos químicos que representan una reacción química.
colloid / coloide – tipo de mezcla en que las partículas (átomos
o moléculas) miden entre 1.0 y 1,000 nanómetros de
diámetro.
chemical formula / fórmula química – representación de un
compuesto que incluye los símbolos y el número de átomos
que forman el compuesto.
combustion reaction / reacción de combustión – reacción en
que una sustancia se combina con el oxígeno, liberando
grandes cantidades de energía en forma de calor y luz.
chemical potential energy / energía química potencial –
energía almacenada en los enlaces químicos.
compounds / compuestos – sustancias formadas por dos o más
elementos, que no se pueden separar mediante procesos
físicos.
chemical reactions / reacciones químicas – rompimiento de
enlaces para la formación de nuevas sustancias (llamadas
productos). Durante las reacciones químicas, los átomos se
reacomodan.
chemical symbol / símbolo químico – abreviatura que
representa el nombre de un elemento. Se utiliza en fórmulas
químicas.
circuit / circuito – véase circuito eléctrico.
circuit diagram / diagrama de circuitos – configuración de un
circuito eléctrico.
circular waves / ondas circulares – onda cuyas crestas forman
círculos.
closed circuit / circuito cerrado – circuito cuyo interruptor está
encendido, impidiendo la interrupción del flujo en el
alambre.
Spanish Glossary
chemical change / cambio químico – cambio en una sustancia
que involucra el rompimiento y la formación de enlaces
químicos, dando como resultado nuevas sustancias.
cochlea / cóclea – diminuta estructura ósea, llena de fluido,
formada por tres tubos y una espiral y que se localiza en el
oído interno. Aquí se encuentra el órgano de la audición.
compression stroke / recorrido de compresión – en un motor
de cuatro tiempos, se refiere a la parte del ciclo en la cual el
combustible y el aire son comprimidos y encendidos por la
bujía.
conceptual model / modelo conceptual – diagrama o
descripción escrita basados en las ideas y las observaciones
que describen cómo funciona un objeto o cómo se realiza
un proceso. La ley de la gravitación universal de Sir Isaac
Newton es un modelo conceptual.
conceptual model / modelo conceptual – modelos descriptivos
que sirven para describir el funcionamiento de algo.
condensation / condensación – proceso mediante el cual una
sustancia en estado gaseoso pierde energía y entra a su
estado líquido.
157
conduction / conducción – transferencia de energía térmica
debido al contacto directo entre las partículas de materia.
cone cells / conos – células fotorreceptoras de la retina del ojo
que responden al color.
conservation of atoms / conservación de átomos – principio
que establece que el número de cada tipo de átomos en el
lado de los reactivos debe ser igual al número de cada tipo
de átomos en el lado de los productos de una ecuación.
consonance / consonancia – combinación armoniosa o
agradable de sonidos.
constructive interference / interferencia constructiva – ocurre
cuando la unión de ondas resulta en una mayor amplitud.
covalent bond / enlace covalente – tipo de enlace químico que
se forma cuando dos o más átomos comparten electrones.
covalente compound / compuesto covalente – compuesto
formado por átomos unidos por enlaces covalentes.
crest / cresta – el punto más alto de una onda.
critical angle / ángulo crítico – ángulo al cual la luz vuelve a
reflejarse totalmente en un material.
current / corriente – cantidad que se refiere a la tasa de flujo
de cargas eléctricas. Se mide en amps.
cyan / azul verdoso – un tipo de luz azulada que se forma
cuando se absorbe el rojo y el verde y el azul son reflejados.
cycle / ciclo – unidad de movimiento que se repite una y otra
vez.
continuous / continuo – conectado a sí mismo.
control variables / variables de control – variables que se
mantienen sin cambio en el transcurso de un experimento.
controlled experiment / experimento controlado –
experimento en que una variable cambia, mientras que las
otras se mantienen constantes o bajo control durante el
transcurso de un experimento.
convection / convección – ocurre cuando el aire caliente
asciende debido a la disminución de su densidad, luego se
expande y libera energía.
deceleration / deceleración – ocurre cuando hay un cambio
negativo en la rapidez o en la aceleración.
decomposition reaction / reacción de descomposición –
reacción química en que un compuesto se descompone,
dando origen a dos o más compuestos más simples.
deformation / deformación – cambio en la forma de un cuerpo,
debido al movimiento.
converge / converger – desviar los rayos de luz de manera que
todos se dirijan hacia un mismo punto.
density / densidad – propiedad que describe la relación entre la
masa y el volumen.
converging lens / lente convergente – tipo de lente que desvía
la luz de manera que los rayos incidentes paralelos se
desvíen hacia el punto focal.
dependent variable / variable dependiente – variable de un
experimento que responde a decisiones tomadas por quien
realiza el experimento; esta variable se grafica en el eje y.
coulomb / culombio – unidad de medida de la carga eléctrica.
158
D
destructive interference / interferencia destructiva – ocurre
cuando la unión de ondas resulta en una menor amplitud.
E
efficiency / eficiencia – se calcula convirtiendo el trabajo de
entrada de una máquina, en trabajo de salida.
diatomic molecules / moléculas diatómicas – una molécula
formada por dos átomos del mismo elemento.
elasticity / elasticidad – medida de la capacidad de un sólido
para recuperar su tamaño original después de ser estirado.
diffraction / difracción – proceso que permite que las ondas se
doblen en las esquinas o pasen a través de aberturas.
electric circuits / circuitos eléctricos – estructuras que
proporcionan las trayectorias por donde se desplaza la
electricidad.
direct current / corriente directa – corriente eléctrica que
fluye en una sola dirección. Se abrevia CD.
electrical conductivity / conductividad eléctrica – capacidad de
un material de conducir (o transportar) electricidad.
dissolution reaction / reacción de disolución – reacción que
ocurre cuando un compuesto iónico se disuelve en agua y
forma una solución iónica.
electrical conductor / conductor eléctrico – material que
conduce electricidad fácilmente.
dissolved / disuelto – estado en el cual las partículas de un
soluto están distribuidas uniformemente en un disolvente.
electrical energy / energía eléctrica – otro término con el que
se conoce la electricidad.
dissolving rate / tasa de disolución – tiempo que tarda cierta
cantidad de soluto en disolverse en un disolvente. Se puede
modificar la tasa de disolución cambiando la temperatura o
mediante procesos físicos como el revolver la solución.
electrical forces / fuerzas eléctricas – fuerza que los materiales
o cuerpos con carga ejercen entre sí.
dissonance / disonancia – combinación de sonidos
discordantes o que causan molestia.
distance / distancia – longitud del espacio entre dos puntos.
diverge / divergencia – desviación de la luz que causa la
separación de los rayos de luz.
diverging lens / lente divergente – tipo de lente que desvía los
rayos de luz fuera del punto focal.
double-displacement reaction / reacción de desplazamiento
doble – reacción en que los iones de dos compuestos
intercambian lugares, produciendo dos nuevos compuestos.
Spanish Glossary
dew point / punto de rocío – temperatura a la cual el aire se
satura de humedad.
electrical insulator / aislante eléctrico – material que es mal
conductor de electricidad.
electrical symbols / símbolos de electricidad – símbolos
sencillos que se usan en los diagramas de circuitos.
electrically charged / eléctricamente cargado – cuerpo que
tiene un exceso de cargas positivas o negativas.
electrically neutral / eléctricamente neutro – cuerpo que posee
igual número de cargas positivas y negativas.
electrolytes / electrolitos – sustancias químicas que forman
iones y conducen corriente eléctrica cuando están disueltas
en agua.
159
electromagnetic force / fuerza electromagnética – fuerza
presente entre cargas eléctricas. A menudo se describe
como fuerza eléctrica o fuerza magnética, dependiendo de
la manera en que interaccionan las cargas.
endothermic reaction / reacción endotérmica – reacción en
que la energía que se requiere para romper los enlaces de
los reactivos es mayor que la energía que se libera al
formarse los nuevos enlaces en los productos.
electromagnetic induction / inducción electromagnética –
generación de energía eléctrica que ocurre cuando un imán
se mueve dentro de una bobina. Los generadores son
instrumentos que funcionan gracias a la inducción
electromagnética.
energy / energía – componente fundamental del universo. Se
presenta en diferentes formas (posición, movimiento y
calor) y se desplaza de diferentes maneras (luz, sonido o
electricidad).
electromagnetic spectrum / espectro electromagnético –
incluye todo el rango de ondas luminosas (radiación
electromagnética).
electromagnets / electroimanes – un imán poderoso y de corta
duración que se puede construir insertando una varilla de
hierro dentro de una bobina que conduce electricidad.
electron / electrón – partícula subatómica de carga negativa
que ocupa niveles energéticos localizados fuera del núcleo
de un átomo. Los electrones participan en la formación de
enlaces químicos y en las reacciones químicas.
electronegativity / electronegatividad – atracción que tiene un
átomo hacia el par de electrones compartidos en un enlace
covalente.
electroscope / electroscopio – instrumento que sirve para
detectar cuerpos con carga.
160
energy level / nivel de energía – región alrededor del núcleo
atómico donde existe una mayor probabilidad de encontrar
los electrones. En cada nivel de energía atómico sólo se
puede encontrar cierto número de electrones.
energy transformation / transformación de energía –
conversión de un tipo de energía en otro. Por ejemplo, una
transformación de energía ocurre cuando la energía
potencial se convierte en energía cinética.
engineering / ingeniería – aplicación de la ciencia en la
resolución de problemas.
engineering cycle / ciclo de ingeniería – proceso que se sigue
para construir instrumentos diseñados con el fin de resolver
problemas. Los cuatro pasos del ciclo son: creación de un
diseño, construcción de un prototipo, prueba del prototipo
y evaluación de los resultados de la prueba.
elements / elementos – sustancias que contienen un solo tipo
de materia.
engineering cycle / ciclo de ingeniería – proceso que se sigue
para construir instrumentos diseñados con el fin de resolver
problemas.
emissions / emisiones – gases y partículas expulsadas a través
del tubo de escape de un auto.
engineers / ingenieros – personas que diseñan tecnología para
resolver problemas.
emiters / emisores – cuerpos que tienen la capacidad de emitir
radiación eficazmente.
English system / sistema inglés – sistema de medidas que
utiliza, por ejemplo, las pulgadas, las yardas y las millas
para medir distancias.
evaporation / evaporación – proceso en el cual una sustancia
en estado líquido adquiere energía y se convierte en un gas.
F
Fahrenheit scale / escala Fahrenheit – escala de temperatura
según la cual el agua se congela a 32 grados Fahrenheit
(32°F) y hierve a 212°F.
excess reactant / reactivo en exceso – reactivo que no se
consume completamente durante una reacción.
fat / grasa – nutriente cuyas moléculas están formadas por
átomos de carbono e hidrógeno y que contiene 9 gramos de
energía por gramo.
exhaust stroke / recorrido de escape – en los motores de
cuatro tiempos, parte del ciclo cuando las válvulas se abren
y dejan salir los gases de escape.
first law of thermodymamics / primera ley de la
termodinámica – establece que la energía se conserva en un
sistema cerrado.
exothermic reactions / reacciones exotérmicas – reacciones
en que la energía requerida para romper los enlaces de los
reactivos es menor que la energía que se libera al formarse
los nuevos enlaces en los productos.
fission / fisión – reacción nuclear en que se divide el núcleo de
un átomo.
experiment / experimento – cualquier situación en la cual se
realizan preparativos para observar los resultados de un
evento.
experimental technique / procedimiento experimental –
procedimiento que se sigue con exactitud cada vez que se
realiza un experimento.
experimental variable / variable experimental – variable de un
experimento que el experimentador modifica. La variable
experimental se grafica como variable independiente en el
eje x.
external combustion engine / motor de combustión externa –
máquina en la cual la quema del combustible ocurre fuera
de ella, como sucede en una máquina de vapor.
fluorescent / fluorescente – tipo de bombilla eléctrica.
Spanish Glossary
equilibrium / equilibrio – (1) ocurre cuando las fuerzas que
actúan sobre un cuerpo están equilibradas; (2) estado de
una solución en que la tasa de disolución del soluto es igual
a su tasa de formación a partir de las sustancias disueltas.
focal length / longitud focal – distancia entre el centro de una
lente y el punto focal.
focal point / punto focal – punto en que los rayos de luz que
cruzan una lente, en línea paralela a su eje, se doblan.
focus / foco – sitio donde todos los rayos de luz que forman un
cuerpo se juntan y forman una imagen.
force / fuerza – atracción, rechazo o cualquier otra acción que
tiene la capacidad de afectar el movimiento.
forced convection / convección forzada – ocurre cuando se
fuerza el movimiento de un gas o de un fluido mediante
medios mecánicos.
formula mass / fórmula masa – es una manera de comparar las
masas de diferentes compuestos. Se calcula sumando las
unidades de masa atómica de todos los átomos de un
compuesto.
161
fossil fuels / combustibles fósiles – hidrocarburos como el
petróleo, el carbón y el gas natural que se extraen de la
Tierra. Los combustibles fósiles son la principal fuente de
energía en Estados Unidos.
free fall / caída libre – aceleración que sufre un cuerpo que cae
bajo la influencia de la fuerza gravitatoria de la Tierra.
frequency / frecuencia – (1) número de ciclos por segundo que
marca un oscilador. (2) número de longitudes de onda que
pasan por cierto punto en un segundo.
friction / fricción – fuerza que resulta del movimiento relativo
entre cuerpos (como la rueda y el eje de un carro).
fulcrum / fulcro – un punto fijo.
fundamental / fundamental – el nombre de la primera
armónica.
fusion / fusión – reacción nuclear en la cual se fusionan los
núcleos de dos átomos para formar un átomo diferente.
G
gamma rays / rayos gamma – fotón emitido espontáneamente
por una sustancia radiactiva.
generator / generador – instrumento que produce energía
eléctrica mediante inducción electromagnética.
global warming / calentamiento global – aumento en la
temperatura de la Tierra debido al aumento en la cantidad
de dióxido de carbono en la atmósfera.
graphical model / modelo gráfico – modelo que mediante una
gráfica muestra la relación entre dos variables, facilitando
así el entendimiento de la relación.
162
gravity / gravedad – fuerza de atracción que existe entre dos
cuerpos que tienen masa.
groundwater / agua subterránea – agua bajo la superficie del
suelo que se acumula en un acuífero y que abastece el agua
de pozos y manantiales.
group of elements / grupo de elementos – elementos que
exhiben propiedades químicas similares y que están
organizados en columnas en la tabla periódica.
H
half-life / media vida – tiempo que tarda la mitad de una muestra
de una sustancia radiactiva en desintegrarse.
hardness / dureza – mide la resistencia de un sólido a ser
rayado.
harmonic motion / movimiento armónico – movimiento que
se repite una y otra vez.
harmonics / armónicas – (1) frecuencias que son múltiplo de
las notas fundamentales. (2) múltiplos de frecuencia
natural.
heat / calor – flujo de energía de un cuerpo a otro debido a
diferencias de temperatura.
heat transfer / transferencia de calor – transferencia de energía
en forma de calor, desde un material con una temperatura
más alta hacia otro con menor temperatura.
heat-temperature rule / regla de calor-temperatura – regla que
establece que entre más calor se le añade a un cuerpo, más
aumenta su temperatura.
hertz / hertz – unidad de un ciclo por segundo que se usa para
medir la frecuencia. Se abrevia Hz.
homogeneous mixture / mezcla homogénea – mezcla en la
cual todas las muestras que se toman son iguales.
horsepower / caballos de fuerza – unidad de potencia. Un
caballo de fuerza equivale a 746 vatios.
humidity / humedad – medida de la cantidad de agua que
contiene el aire.
hidrate / hidrato – compuesto que tiene moléculas de agua
unidas químicamente a sus iones.
I
image / imagen – reproducción visual de un cuerpo que se
forma en el punto donde se unen o convergen los rayos de
luz provenientes del cuerpo.
incandescence / incandescencia – proceso de creación de luz
por medio del calor.
incandescence / incandescencia – proceso de creación de luz
por medio del calor.
incident ray / rayo incidente – rayo que proviene de un cuerpo.
hydrated / hidratado – combinado con agua o con los
elementos que forman el agua.
independent variable / variable independiente – variable de un
experimento que manipula el experimentador y que
produce cambios en la variable dependiente. Se grafica en
el eje x.
hydrochloric acid / ácido clorhídrico – sustancia muy ácida
que el estómago produce normalmente para digerir
alimentos.
index of refraction / índice de refracción – tasa que indica
cuánto se reduce la velocidad de la luz cuando pasa a través
de un material.
hydrogen bond / enlace de hidrógeno – enlace débil entre el
extremo de una molécula de agua con carga parcial positiva
y el extremo de otra molécula de agua con carga parcial
negativa.
inertia / inercia – resistencia de un cuerpo a cambiar su estado
de reposo o de movimiento.
hydrologic cycle / ciclo hidrológico – describe la trayectoria del
agua en la Tierra mediante los procesos de evaporación,
condensación, precipitación y transpiración.
hypothesis / hipótesis – predicción que puede ser comprobada
mediante experimentación.
Spanish Glossary
heterogeneous mixture / mezcla heterogénea – tipo de mezcla
en la cual, si se toman varias muestras, todas ellas
contendrán distintas proporciones de los diferentes
componentes de la mezcla.
infrared light / luz infrarroja – radiación electromagnética,
incluyendo el calor, con longitudes de onda mayores que el
espectro visible.
input / entrada – incluye todo lo que se necesita hacer para que
funcione una máquina.
input arm / brazo de entrada – si se coloca una palanca sobre
un fulcro, el brazo de entrada es el lado de la palanca donde
se aplica la fuerza de entrada.
input force / fuerza de entrada – fuerza que se le aplica a una
máquina.
163
insoluble / insoluble – término que describe una sustancia que
no se disuelve en agua.
K
instantaneous speed / rapidez instantánea – la rapidez de un
cuerpo en un punto específico de su trayectoria.
kilocalories / kilocalorías – cantidad de calor que se requiere
para elevar en 1°C la temperatura de un kilogramo de agua.
Se abrevia kcal.
intake stroke / recorrido de admisión – en un motor de cuatro
tiempos, es la parte del ciclo en que el aire y el combustible
entran al cilindro.
internal combustion engine / motor de combustión interna –
máquina en la cual el proceso de quema del combustible
ocurre dentro del cilindro.
investigation / investigación – una o más experiencias que
tratan de responder la misma pregunta.
ion / ion – átomo con carga eléctrica.
ionic bond / enlace iónico – tipo de enlace químico entre
átomos que ganaron o perdieron electrones. Enlace entre
iones.
ionic ompound / compuesto iónico – compuesto formado por
iones.
isotopes / isótopos – formas de un mismo elemento que tienen
diferente número de neutrones y diferente número de masa.
J
joule / julio – unidad de medida del trabajo. Un julio equivale
a un newton de fuerza por un metro de distancia. Se abrevia
J.
kilowatt / kilovatio – medida equivalente a 1,000 vatios ó
1,000 julios por segundo.
kilowatt-hour / kilovatio-hora – indica que se ha utilizado un
kilovatio de potencia en una hora.
kinetic energy / energía cinética – energía que proviene del
movimiento.
Kirchoff's current law / ley de las corrientes de Kirchoff –
establece que la cantidad de corriente que entra en una rama
de un circuito es igual a la cantidad que sale de la rama.
Kirchoff's voltage law / ley de las tensiones de Kirchoff –
establece que en un circuito completo, la energía extraída
debe ser igual a la energía proporcionada por la batería.
L
latent heat / calor latente – calor que no puede detectarse con
un termómetro.
latent heat / calor latente – calor liberado cuando el vapor se
condensa en líquido.
latitude / latitud – distancia angular al norte o al sur del ecuador
de la Tierra y que mide entre 0 y 90 grados.
law of conservation of mass / ley de conservación de la masa
– establece que la masa total de los productos de una
reacción es igual a la masa total de los reactivos.
164
length / longitud – unidad de medida de la distancia.
lens / lente – material transparente, como el vidrio, al que se le
da cierta forma y que sirve para desviar los rayos de luz.
lever / palanca – estructura rígida que rota alrededor de un
punto fijo, llamado fulcro.
limiting reactant / reactivo limitador – reactivo que se agota
primero durante una reacción.
longitudinal wave / onda longitudinal – onda que oscila en la
misma dirección que el movimiento de la onda.
M
machine / máquina – tipo de sistema mecánico.
magenta / magenta – color rosado purpúreo que se forma
cuando el verde es absorbido y el rojo y el azul son
reflejados.
magnetic field / campo magnético – área con fuerza magnética
que rodea los cuerpos magnéticos.
magnetic force / fuerza magnética – fuerza ejercida sobre una
partícula o cuerpo que se desplaza a través de un campo
magnético.
magnetic north pole / polo norte magnético – el extremo de
un cuerpo magnético que apunta hacia el polo norte
geográfico de la Tierra.
magnetic south pole / polo sur magnético – el extremo de un
cuerpo magnético que apunta hacia el extremo opuesto al
polo norte geográfico de la Tierra.
malleability / maleabilidad – capacidad de un sólido de formar
láminas.
mass / masa – una medida de la inercia de un cuerpo.
mass number / número de masa – la suma total de los protones
y los neutrones en el núcleo atómico.
matter / materia – cualquier cosa que tiene masa y ocupa
espacio.
measurement / medición – el acto o proceso de medir en
múltiplos de una unidad específica.
mechanical advantage / ventaja mecánica – proporción de la
fuerza de salida en relación con la fuerza de entrada.
Spanish Glossary
law of conservation of moment / ley de conservación del
momento – establece que mientras los cuerpos que
interactúan no sean afectados por fuerzas externas (como la
fricción), el valor del momento antes de la interacción será
igual al valor del momento después de la interacción.
mechanical system / sistema mecánico – serie de piezas
movedizas interrelacionadas.
metabolic rate / tasa metabólica – tasa general de consumo de
energía (en reposo o en actividad) o el funcionamiento de
una sustancia específica dentro del cuerpo.
metric system / sistema métrico – sistema de medición que,
por ejemplo, utiliza milímetros, centímetros, metros y
kilómetros para medir distancias.
mixture / mezcla – sustancia que contiene más de un tipo de
materia.
mole / mol – conjunto de 6.02 × 10/23/ átomos o moléculas.
molecular formula / fórmula molecular – número real de los
átomos de cada elemento en un compuesto.
molecule / molécula – partícula de un compuesto que mantiene
las propiedades del compuesto.
165
momentum / momento – la masa de un cuerpo multiplicada
por su rapidez o su velocidad.
monoatomic ions / iones monoatómicos – iones que contienen
un solo tipo de átomo.
musical scale / escala musical – frecuencias sonoras que se
ajustan a un patrón especial.
N
nanometer / nanómetro – unidad de medida equivalente a una
billonésima de metro.
natural (or buoyant) convection / convección natural (o de
flotabilidad) – proceso influido por la fuerza de gravedad y
mediante el cual el aire menos denso desplaza el aire más
frío y de mayor densidad.
natural requency / frecuencia natural – describe la vibración de
un cuerpo, como la cuerda de una guitarra que es rasgueada
repetidamente con la misma frecuencia de vibración.
natural world / mundo natural – aspectos del mundo que no
son creados ni construidos por los seres humanos.
negative charge / carga negativa – uno de los dos tipos de carga
eléctrica. El otro tipo es la carga positiva.
net force / fuerza neta – cantidad de fuerza que produce
movimiento al superar una fuerza opuesta.
neutral / neutra – (1) solución con un pH de 7, lo cual significa
que tiene igual cantidad de H+ y OH-, o la misma cantidad
de iones ácidos y básicos. (2) ocurre cuando la carga de un
protón es anulada por la carga de un electrón.
166
neutrons / neutrones – partícula elemental sin carga. Su masa
es casi igual a la masa del protón. Todos los núcleos
atómicos, con excepción del hidrógeno, presentan
neutrones.
newton / newton – unidad de medida de la fuerza.
Newton's first law of motion / primera ley del movimiento de
Newton – establece que un cuerpo permanecerá en reposo
a menos que sea afectado por una fuerza desequilibrada.
Esta ley también establece que un cuerpo en movimiento
continuará moviéndose con dirección y rapidez constantes,
a menos que sea afectado por una fuerza desequilibrada.
Newton's second law of motion / segunda ley del movimiento
de Newton – establece que la aceleración de un cuerpo es
directamente proporcional a la fuerza que actúa sobre él e
inversamente proporcional a su masa.
Newton's third law of motion / tercera ley del movimiento de
Newton – establece que cuando un cuerpo ejerce una
fuerza sobre otro cuerpo, el segundo cuerpo ejerce una
fuerza igual y opuesta sobre el primer cuerpo.
nonpolar / no polar – término que sirve para describir una
molécula o enlace covalente que no tiene cargas parciales.
Los aceites y las grasas son moléculas no polares.
normal / normal – línea perpendicular a la superficie de un
cuerpo.
nuclear energy / energía nuclear – forma de energía que se
obtiene de la división del núcleo atómico o de la fusión de
dos núcleos atómicos.
nuclear reactions / reacciones nucleares – reacción en la cual
el núcleo de un átomo se divide o reacción en que dos
núcleos se fusionan. Este tipo de reacciones producen
mucha más energía que las reacciones químicas.
nucleons / nucleones – incluye los protones y los neutrones del
núcleo.
O
octet / octeto – los 8 electrones de valencia de un átomo.
octet rule / regla del octeto – establece que los átomos crean
enlaces con otros átomos mediante la transferencia o el
compartimiento de electrones, para completar así sus
respectivos octetos y adquirir estabilidad.
parallel / paralelo – que yace o que se mueve en la misma
dirección, pero siempre a una distancia constante de
separación (es decir, nunca se interseca).
parallel circuit / circuito paralelo – circuito en el cual la
corriente puede seguir más de una trayectoria.
peak-to-peak / cresta a cresta – diferencia entre el valor mayor
y el valor menor de una gráfica.
percent yield / rendimiento porcentual – rendimiento real de
una reacción, dividido entre el rendimiento teórico y
multiplicado por cien, para obtener un porcentaje.
ohm / ohm – unidad de medida de la resistencia eléctrica.
period / período – el tiempo que dura un ciclo.
Ohm's law / ley de Ohm – describe las reacciones matemáticas
presentes en la mayoría de los circuitos.
periodic motion / movimiento periódico – ciclos de
movimiento que se repiten una y otra vez. Es lo mismo que
el movimiento armónico.
open circuit / circuito abierto – circuito cuyo interruptor está
apagado, ocasionando una interrupción del flujo en el
alambre.
optics / óptica – estudio del comportamiento de la luz.
oscillator / oscilador – sistema que presenta movimientos
armónicos.
output / salida – lo que realiza una máquina.
Spanish Glossary
nucleus / núcleo – el centro de un átomo que contiene protones
y neutrones.
P
periodic table of elements / tabla periódica de los elementos
– tabla en que se organizan visualmente los elementos
conocidos según la similitud de sus propiedades.
periodic table of elements / tabla periódica de los elementos
– tabla en que se organizan visualmente los elementos
conocidos según la similitud de sus propiedades.
output arm / brazo de salida – en una palanca sobre un fulcro,
se refiere al lado donde se aplica la fuerza de salida.
permanent magnet / imán permanente – cuerpo magnético que
mantiene sus propiedades magnéticas sin requerir
influencias externas.
output force / fuerza de salida – fuerza que una máquina aplica
para realizar una tarea.
perpendicular / perpendicular – que forma un ángulo de
90 grados con una superficie o con una arista.
oxidation number / número de oxidación – indica el número
de electrones que se comparten, se ganan o se pierden
cuando se forma un enlace.
pH / pH – la concentración exacta de iones H+ y iones OH- en
una solución.
167
pH indicator / indicador de pH – solución o cuerpo que al
cambiar de color identifica el pH de una solución.
pH scale / escala de pH – escala que va del 1 (ácido muy fuerte)
al 14 (base muy fuerte o alcalina).
phase / fase – se refiere al punto del ciclo en que se encuentra
un oscilador.
polarization / polarización – una manera de describir la
dirección (por ejemplo, en sentido vertical u horizontal) en
que viajan las ondas de luz.
photochemical receptors / receptores fotoquímicos – células
en la retina del ojo que, al detectar luz, liberan una señal
química que viaja hasta el encéfalo a través del nervio
óptico.
polarizer / polarizador – material casi transparente que permite
el paso de un tipo de luz polarizada.
photoluminescence / fotoluminiscencia – ocurre cuando la
energía luminosa hace que un cuerpo emita luz.
polymer / polímero – molécula grande compuesta de unidades
más pequeñas que se repiten y que se conocen como
subunidades o monómeros.
photosynthesis / fotosíntesis – reacción química que realizan
las plantas y que les permite convertir la energía solar en
energía química. Durante esta reacción el dióxido de
carbono se usa para elaborar azúcares.
physical changes / cambios físicos – cambios en las propiedades
físicas de una sustancia.
physical models / modelos físicos – modelos que se pueden
tocar y medir y que están construidos con diversos
materiales. Los ingenieros construyen modelos físicos a
escala para poner a prueba una estructura antes de
construirla.
polyatomic ions / iones poliatómicos – iones que contienen
más de un tipo de átomo.
polymerization / polimerización – producción de una molécula
muy grande mediante una serie de reacciones de síntesis.
position / posición – punto en el espacio donde se localiza un
cuerpo, en relación con su punto de partida.
positive charge / carga positiva – uno de los dos tipos de carga
eléctrica. El otro tipo es la carga negativa.
potential energy / energía potencial – energía almacenada
debido a la posición.
potentiometer / potenciómetro – una resistencia variable.
pounds / libras – unidad de fuerza del sistema inglés.
pitch / tono – propiedad del sonido determinada por la
frecuencia de las ondas que lo producen.
power / potencia – tasa a la cual se realiza trabajo.
pixel / pixel – punto en la pantalla de la computadora que
consta de tres números y que le indica a la computadora qué
color producir.
power stroke / recorrido de potencia – en un motor de cuatro
tiempos, es la parte del ciclo en que el combustible se
calienta, se expande y empuja el pistón.
plane waves / ondas planas – ondas cuyas crestas parecen
líneas rectas.
168
polar / polar – algo que tiene dos polos. Término que se usa
para describir una molécula o enlace covalente con cargas
parciales. El agua es una molécula polar.
R
radiant energy / energía radiante – otro término con el que se
conoce la energía electromagnética.
precipitation / precipitación – vapor de agua en la atmósfera
que cae a la superficie de la Tierra en forma de lluvia,
granizo, cellisca o nieve.
radiation / radiación – (1) proceso de emisión de energía
radiante. (2) término que se utiliza para describir las
partículas y la energía emitidas por sustancias radiactivas.
pressure / presión – medida de la fuerza ejercida sobre las
paredes de un recipiente.
radiation / radiación – tipo de transferencia de calor que ocurre
a través de ondas electromagnéticas.
procedure / procedimiento – todo el conjunto de técnicas
utilizadas durante un experimento.
radioactive / radiactivo – término que describe átomos cuyos
núcleos emiten radiación en forma de partículas y energía,
hasta que adquieren una mayor estabilidad.
products / productos – sustancias producidas a partir de los
reactivos durante una reacción química.
protein / proteína – molécula que contiene nitrógeno y que se
encuentra en los alimentos. Sirve para construir partes
estructurales de las células.
radioactive isotope / isótopo radiactivo – isótopo inestable de
un elemento que sufre desintegración radiactiva de manera
espontánea.
Spanish Glossary
precipitate / precipitado – sustancia que se forma cuando uno
de los compuestos de una reacción de desplazamiento doble
es insoluble, es decir, no se disuelve en agua.
ray diagrams / diagramas de rayos – diagrama que ilustra el
comportamiento de los rayos de luz cuando pasan a través
de un sistema.
protons / protones – partícula elemental idéntica al núcleo de
un átomo de hidrógeno. Al igual que los neutrones, se
encuentra en todos los núcleos atómicos. Tiene carga
positiva.
react / reaccionar – ocurre cuando un átomo forma un enlace
atómico con otro átomo.
prototype / prototipo – modelo de prueba que sirve para
probar si un instrumento funciona bien.
reactants / reactivos – sustancia que participa y se modifica
durante el curso de una reacción química.
real image / imagen real – imagen formada por la convergencia
de los rayos de luz en una superficie como la de una
pantalla o como la retina del ojo.
recoil / retroceso – aceleración negativa causada por la fuerza
de reacción.
reflected ray / rayo reflejado – rayo que rebota sobre un
cuerpo.
169
reflection / reflexión – onda que rebota al chocar con un
obstáculo.
reflectors / reflectores – cuerpos que reflejan la luz.
refraction / refracción – ocurre cuando la luz se desvía debido
a que atraviesa dos materiales (transparentes) diferentes.
refraction / refracción – estado de una onda cuando cruza un
límite donde cambian las condiciones.
relative humidity / humedad relativa – cantidad de vapor de
agua en el aire.
relative mass / masa relativa – cifra que permite comparar entre
cantidades de materia muy pequeñas.
research question / pregunta de investigación – pregunta que
se resuelve mediante una investigación.
resistance / resistencia – medida de la capacidad de un cuerpo
de conducir corriente.
resistors / resistencias – componentes que sirven para
controlar la corriente en muchos circuitos.
resonance / resonancia – sucede cuando la frecuencia natural
de un sistema está exactamente en el mismo tono que una
fuerza.
reverberation / reverberación – ecos múltiples de un sonido.
rod cells / bastones – células fotorreceptoras de la retina del
ojo que responden a diferencias en brillo.
rolling friction / fricción de rodamiento – resistencia que
ocurre cuando un cuerpo rueda sobre otro.
170
S
saturated / saturado – estado de una mezcla en que una
solución contiene la mayor cantidad posible de soluto.
scientific evidence / prueba científica – cualquier observación
que se puede repetir, obteniendo los mismos resultados.
scientific method / método científico – proceso que permite
obtener datos que aumentan nuestro conocimiento del
mundo.
scientific model / modelo científico – método para representar
las relaciones entre las variables.
sea breeze / brisa marina – corriente de aire que se origina
cuando el aire caliente sobre la superficie terrestre asciende
debido a la convección y es reemplazado por aire más
fresco.
second / segundo – unidad común para medir el tiempo.
Equivale a 1/60 de un minuto.
semiconductor / semiconductor – material cuya
conductividad eléctrica se encuentra entre la de un
conductor y la de un aislante.
series circuit / circuito en serie – circuito en que la corriente
sólo puede seguir una trayectoria.
short circuit / cortocircuito – rama de un circuito con
resistencia cero o con resistencia muy baja.
simple machine / máquina simple – instrumento mecánico sin
fuente propia de energía, como una palanca, que tiene una
fuerza de entrada y una fuerza de salida.
sliding friction / fricción de deslizamiento – resistencia que se
produce cuando dos cuerpos se rozan entre sí.
solar energy / energía solar – energía que se puede utilizar al
transformar la energía radiante del Sol.
solubility / solubilidad – se refiere a la cantidad de soluto que se
puede disolver, en una cierta cantidad de volumen de un
disolvente, bajo ciertas condiciones.
solubility rules / reglas de solubilidad – conjunto de reglas que
permite determinar si una combinación de iones se
disolverá en agua o formará un precipitado.
solubility value / valor de solubilidad – incluye la masa del
soluto, la cantidad del disolvente y la temperatura.
solute / soluto – sustancia en menor cantidad en una solución.
El soluto se disuelve en el disolvente.
solution / solución – mezcla entre dos o más sustancias que es
homogénea a nivel molecular. Una solución consta de un
soluto y un disolvente.
solvent / disolvente – es el componente más abundante de una
solución. Se encarga de disolver el soluto.
sonogram / sonograma – tipo especial de gráfica que muestra
el grado de intensidad de un sonido en diferentes
frecuencias.
spectral diagram / diagrama espectral – diagrama que muestra
la longitud de onda y la intensidad de la luz emitida por una
fuente.
speed / rapidez – describe el movimiento de un cuerpo de un
sitio a otro, con respecto al tiempo.
stable / estable – término con el que se describe un átomo con
cargas equilibradas y que no tiene un núcleo radiactivo.
standing wave / onda estacionaria – onda atrapada en un punto.
static electricity / electricidad estática – (1) acumulación de
cargas positivas o negativas. (2) consta de cargas aisladas e
inmóviles, como las causadas por la fricción.
strong nuclear force / fuerza nuclear fuerte – fuerza que
mantiene unidos los protones cuando están muy cercanos
entre sí (a una distancia de 10-13).
subatomic particles / partículas subatómicas – partículas más
pequeñas que un átomo.
subscripts / subíndices – números de una fórmula química que
muestran la cantidad de cada tipo de átomo.
Spanish Glossary
single–displacement reaction / reacción de desplazamiento
simple – reacción química en que un elemento sustituye un
elemento similar en un compuesto.
substance / sustancia – mezcla que no se puede separar en
diferentes tipos de materia mediante procesos físicos.
substractive primary colors / colores primarios substractivos
– magenta, amarillo y azul verdoso.
supersaturated / supersaturada – solución que contiene una
cantidad de soluto mayor a la que normalmente puede
contener a una temperatura dada.
supersonic / supersónico – movimiento que es más rápido que
el sonido.
surface runoff / escorrentía – agua que fluye sobre el terreno
hasta que llega a lagos, ríos y otras aguas superficiales.
surface water / aguas superficiales – agua de lagos, represas,
estanques, ríos, corrientes de agua y reservorios.
171
suspensions / suspensiones – tipo de mezcla que contiene
partículas (átomos o moléculas) con un diámetro mayor que
1,000 nanómetros.
thermostat / termostato – instrumento que controla el
funcionamiento de otro instrumento, de acuerdo con los
cambios de temperatura.
system / sistema – conjunto de materia y procesos que ocurren
en cierto espacio y que se pueden estudiar. Los sistemas
pueden ser abiertos o cerrados.
time / tiempo – unidad que sirve para medir los cambios en
movimiento o en eventos, abordándolos de manera total o
parcial en el presente, el pasado y el futuro.
T
temperature / temperatura – unidad de medida que sirve para
cuantificar las sensaciones de calor y frío.
tensile strength / resistencia a la tensión – medida de la
cantidad de tensión o estiramiento que un material puede
soportar antes de romperse.
terahertz / terahertz – unidad de medida equivalente a
1,000,000,000 de ciclos por segundo.
thermal conductivity / conductividad térmica – capacidad de
un material para transferir calor.
thermal conductors / conductores térmicos – materiales que
conducen calor con facilidad.
thermal energy / energía térmica – energía proveniente del
calor y la vibración de átomos y moléculas.
thermal equilibrium / equilibrio térmico – cuerpos que tienen
la misma temperatura.
thermal insulators / aislantes térmicos – materiales que son
malos conductores de calor.
thermometer / termómetro – instrumento que sirve para
medir la temperatura. Generalmente, consta de un líquido
que asciende y desciende dentro de un tubo.
172
total internal reflection / reflexión interna total – ocurre
cuando la luz es reflejada porque se aproxima a una
superficie con un ángulo mayor que el ángulo crítico.
transpiration / transpiración – proceso a partir del cual las
plantas, al abrir pequeños poros en sus hojas, obtienen
dióxido de carbono y pierden agua.
transverse wave / onda transversal – onda que oscila de
manera perpendicular a la dirección de la trayectoria de la
onda.
test / prueba – cada una de las veces que se realiza un
experimento.
trough / valle – punto más bajo de una onda.
turbine / turbina – máquina cuyo árbol o eje propulsor tiene
paletas que giran debido a la presión del agua, del vapor de
agua o de un gas.
Tyndall effect / efecto de Tyndall – método usado para
distinguir visualmente entre coloides y soluciones
verdaderas.
U
unsaturated / no saturada – solución en que se puede disolver
más soluto.
volt / voltio – unidad de medida del voltaje.
voltage / voltaje – cantidad de energía potencial que posee cada
unidad de carga eléctrica.
W
water cycle / ciclo del agua – véase ciclo hidrológico.
watt / vatio – unidad del sistema métrico, o SI, de medición de
la potencia.
V
valence electrons / electrones de valencia – electrones de un
átomo que participan en la formación de enlaces químicos.
variables / variables – factores que afectan los resultados de un
experimento.
versorium / versorio – la primera versión de los electroscopios
modernos.
virtual image / imagen virtual – imagen que se forma cuando
los rayos de luz parecen provenir de un sitio diferente del
sitio en el cual se encuentra el objeto real.
viscosity / viscosidad – medida de la resistencia a fluir de un
material
viscous friction / fricción viscosa – fuerza que se opone al
movimiento de los cuerpos en el agua o en otros fluidos.
wavefronts / frente de onda – otro término con el que se
describe la cresta de una onda.
wavelength / longitud de onda – distancia entre pico y pico,
cresta y cresta o valle y valle de una onda.
Spanish Glossary
ultraviolet light / luz ultravioleta – luz más allá del espectro
visible. Tiene una longitud de onda más corta que la luz
visible, pero mayor que la de los rayos X.
visible light / luz visible – luz que puedes ver. Mide entre
400 y 700 nanómetros.
weight / peso – fuerza creada por la gravedad.
white noise / ruido blanco – mezcla de cantidades iguales de
todas las frecuencias. Análogo al color blanco, que es una
mezcla de todos los colores.
work / trabajo - cantidad de fuerza por distancia. El resultado
de la tarea o actividad que realiza una máquina.
Y
yellow / amarillo – color que se produce cuando el azul es
absorbido y el rojo y el verde son reflejados.
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174
Equipment Setup
This section contains information about the equipment that comes with the CPO Integrated Physics
and Chemistry program.
Physics Stand .................................................................................... 176
Timer and Photogates ........................................................................ 177
Car & Ramp ...................................................................................... 180
Ropes & Pulleys ................................................................................ 182
Lever ................................................................................................ 184
Rollercoaster ..................................................................................... 185
Electric Circuits ................................................................................ 187
Electric Motor ................................................................................... 188
Pendulum .......................................................................................... 192
Sound & Waves Generator ................................................................. 194
CPO Optics Kit ................................................................................. 196
Spectrometer ..................................................................................... 197
Displacement Tank ............................................................................ 198
Atom Building Game ......................................................................... 199
Periodic Table Tiles ........................................................................... 200
Equipment Set Up
Contents
175
Physics Stand
The CPO Physics Stand
Assembly
Used with almost all of the CPO equipment, the
Physics Stand has a sturdy 1-meter, square
aluminum pole with holes every 5 cm for
attaching various pieces of equipment. The solid
hardwood base has three adjustable leveling
feet.
Step One: Place bolt through bottom of
Physics Stand base
Place one large washer on the bolt and slip the
bolt through hole the in the center of the
bottom of the Physics Stand base.
Step Three: Tightening the assembly
With the pole and base connected, rest the
base on a table and hold the pole in one hand.
Insert the steel rod into the hole of the bolt on
the bottom of the base. While holding the pole,
use the steel rod to tighten the entire assembly.
Materials Checklist
D 1 Large bolt
D 2 Large washers
D 1 Physics Stand base
D 1 Physics Stand pole
D 1 Small steel rod
Step Two: Attaching pole to base
Place the second large washer on the bolt as it
comes through the top of the Physics Stand
base. Using care not to cross-thread the parts,
screw the Physics Stand pole on to the bolt.
176
Step Four: Attaching selected equipment
Place the Physics Stand upright on a table and
level the assembly by adjusting the three feet on
the bottom of the base. Your stand is now ready
for the selected equipment to be attached.
Attach equipment using the instructions found
on the following setup pages. Each piece of
equipment has its own set of assembly
instructions.
Timer and Photogates
1
This section describes operation of the CPO
Timer II electronic photogate timer. It is used in
many experiments describing motion, sound,
and waves. Much of the material in this section
is also covered in the Timer Reference Guide
that is included with the unit.
You should have the following parts.
Replacement parts can be ordered using the
part numbers given in the CPO catalog..
Contents
1
2
3
4
5
6
7
What’s in the Case
Connections
Lights and Buttons
The Photogates
Using Stopwatch Mode
What’s in the Case
Quantity
Description
1
Timer
2
Photogates
1
AC Adapter
2
Phone Cord (red or blue)
1
Timer Manual
1
Case
1
optional 9V battery
2
Connections
Inputs A and B are for connecting the
photogates or the Sound and Waves
experiment. DO NOT plug telephone
equipment, modems, OR ANYTHING ELSE
into the inputs or you risk damaging the Timer
and/or the telephone equipment.
Measuring Time Intervals with Photogates
Equipment Setup
The Timer II
Two Lights and Three Stopwatches
You can use standard
telephone wires to
connect the photogates. BUT beware of
computer data cables
that look like telephone wires (same connector)
but have the wires reversed inside. Using a
computer data cable will ruin a photogate (see
section 4).
The Timer can run from a 9V battery or the
included 500 mA, 9VDC power adapter. The
adapter has a positive center pin as shown in
the diagram.
177
(continued) Timer and Photogates
3
Lights and Buttons
4
The Photogates
The five buttons control the Timer, and the
lights tell you what the Timer is measuring and
displaying.
178
Mode Button:
The mode button switches
the Timer between modes
Mode Lights:
The five lights tell you which
mode the Timer is in.
(A)
Button:
The “A” button switches the
“A” light on and off.
A Light:
The “A” light indicates the
Timer is displaying data from
input A.
(B)
Button:
The “B” button switches the
“B” light on and off.
B Light:
The “B” light indicates the
Timer is displaying data from
input B.
(O)
Reset Button:
The reset button initializes
the Timer back to zero, or
freezes the display.
(?)
Memory
Button:
The memory button allows
you to display the last
interval measurement.
The Photogates use an invisible beam of infrared light to start and stop the Timer. The
photogates connect to the sockets behind the
(A) and (B) buttons with two telephone cords.
When the photogate is working properly, the
status light should go off and on when you
interrupt the light beam. The Timer can work
with one or two photogates connected.
For convenience we refer to the Photogate
plugged into input (A) as gate A. and the one
connected to input (B) as gate B. It does not
matter which color wire you use. The wires are
electrically identical and the different colors
allow you to tell quickly which is “A” and which
is “B”.
CAUTION: Overtightening the screws can flex
the photogate body enough that the light
emitter and reciever twist out of alignment,
causing it to malfunction. Loosening the screw
will fix the problem. TIGHTEN THE SCREWS
GENTLY.
The photogates connect with ordinary
telephone cords. You can get replacements (or
longer ones) from almost any hardware or
office supply store. CAUTION: Computer data
cables have the same (RJ-11) connectors and
look like telephone cords but are wired
differently inside. Using a data cable will ruin the
Photogates.
(continued) Timer and Photogates
5
Using Stopwatch Mode
Measuring Time Intervals with
Photogates
In interval mode, the timer uses one or two
photogates to electronically start and stop up to
three stopwatches. The time measurements are
much more precise because the light beam can
respond much faster than your finger. Using the
photogates, the timer can measure to one ten
thousandth (0.0001) of a second.
7
2 Lights and 3 Stopwatches
The Timer in interval mode works like it has
three stopwatches.
The picture below shows how the two
photogates can be connected and how the lights
control the display of time measurements made
with the three stopwatches.
In stopwatch mode the Timer measures in
seconds and is accurate to one hundredth
(0.01) of a second from 0.01 to 59.99 seconds.
After 1 minute, the display switches to
minutes:seconds format and the display is
accurate to whole seconds. The stopwatch can
time up to 199 minutes and 59 seconds
(199:59).
Stopwatch A starts when the light beam is
broken in photogate A and stops when the light
beam is unbroken again. Stopwatch A measures
the time interval the light beam is broken in A.
Equipment Setup
The stopwatch function is the simplest of the
different modes. The picture below shows how
stopwatch mode works.
6
Stopwatch B starts when the light beam is
broken in photogate B and stops when the
beam is unbroken. Stopwatch B measures the
time interval the light beam is broken in B.
Stopwatch AB is controlled by both photogates.
Breaking the beam in A starts the stopwatch
and breaking the beam in B stops it. Stopwatch
AB measures the time interval from A to B.
The Timer can use all three stopwatches
simultaneously. You can measure up to three
time intervals at once. The (A) and (B) lights
and the (A) and (B) buttons control how the
Timer displays the results. The buttons toggle
the lights on and off. The lights tell you which of
the three stopwatches is being displayed.
179
Car & Ramp
The Car & Ramp
Assembly
Step Three: Securing the ramp foot
The Car & Ramp is an excellent tool for
teaching and learning about forces and motion.
Students are able to perform accurate and
repeatable experiments that explore the
concepts of speed and acceleration, Newton’s
Laws, simple machines, and friction. The
hardwood ramp is 48” long and has a pulley
mounted at one end for added versatility. The
car has all-metal ball bearing wheels, eyelets for
attaching strings or force scales, and a threaded
center post for securing weights.
Step One: Assemble the Physics Stands
Place the foot under the end of the ramp that
sits on the table, and secure it by sliding it into
the square hole.
Materials Checklist
D 1 Physics Stand assembly
D 1 Hardwood ramp
D 1 Car with wing nut
D 1 Hardwood foot for the ramp
D 1 Black plastic knob
D 1 Timer unit with power adapter
D 2 Photogates with wires
D Optional - Weight Set
D Optional - Spring Scales
D Optional - String
180
Assemble the appropriate number of Physics
Stands (based on how many lab stations are to
be set up) by following the instructions on the
Physic Stand Setup.
Step Two: Attaching the ramp to the
Stand
Attach the ramp to the Physics Stand by placing
the threaded rod at the pulley-end of the ramp
through the desired stand hole. Secure by using
the black plastic knob.
Step Four: Placing the car on the Ramp
Place the car on the ramp by fitting the wide
head of the screw through the key-hole at the
top of the ramp. The 5 cm wing on the car
should be on the side of the ramp with the scale
printed on it. Weights can now be added to the
car to change its mass. Secure using the wingnut.
Step Five: Setting up the Timer and
Photogates on the ramp
Equipment Setup
Open the photogates by turning the aluminum
knobs counter-clockwise. Place the photogates
at the desired position on the scale side of the
ramp, ensuring that the Photogates fit flush
against the edge of the ramp. Tighten knobs to
lock into position.
Connect the Photogates to the A and B slots of
the Timer unit using the supplied red and blue
wires. Be sure the car passes through Photogate
A first, then Photogate B. The Timer should be
set to Interval mode, and both A and B lights
should be lit on the unit. If set up properly, the 5
cm wing on the car will trigger the Photogates.
Note: For detailed instructions on using the
Timer and Photogates, refer to the Timer and
Photogates Setup.
181
Ropes & Pulleys
The Ropes & Pulleys
Assembly
The Ropes & Pulleys set is an ideal tool for
teaching students the concepts of simple
machines, force, work, and energy. The unique
construction of this apparatus helps prevent
hopelessly tangled strings and features lowfriction ball bearing pulleys for accurate force
measurements. Simple block and tackle
machines with mechanical advantage from 1 to
6 are easy to construct.
Materials Checklist
D 1 Pulley block assembly
Physic Stand Setup.
Step two: Attach the pulley block
assembly to the Physics Stand
Slide the threaded rod that is attached to the
upper pulley block through the selected hole in
the Physics Stand (preferably one near the top).
Secure the pulley block with the black plastic
knob. You should now have the upper pulley
block secured, while the lower pulley block
hangs below on the two red safety strings.
D 1 Threaded knob with attached
black plastic knob
D 1 Set of Weights
D 1 Set of Spring Scales
D 1 Yellow string with cord stops
D 1 Tape measure
Step three: Attaching weight to the lower
pulley block
Add weight to the lower pulley block by sliding
the threaded rod with attached black knob
through the center hole of the weights and
screwing it into the bottom of the lower pulley
block.
182
Step four: Weighing the lower pulley
block
After the weight has been secured, weigh the
lower pulley block assembly by hanging it on a
spring scale using the eyelet that is screwed into
the top of it. Record the weight.
Step five: Stringing the pulley blocks for a
specific mechanical advantage
diagram below shows a mechanical advantage of
one.
The first step of stringing the Ropes & Pulleys is
to choose where to connect the brass clip on
the end of the yellow string. The clip can either
be attached to the upper pulley block or the
lower pulley block using the eyelet on either
block.
If the string is connected to the lower pulley
block a mechanical advantage of 1, 3 or 5 can be
obtained (1, 3, or 5 supporting strings). The
In addition to weighing the bottom block, there
are three other measurements to take.
To measure effort force, slip the spring scale
hook over a cord stop. Now pull the spring
scale to raise the lower pulley block. Record the
force measurement from the spring scale.
To measure effort length, place a cord stop on
the yellow string up against the pulley on the
upper block. When positioning the cord stop,
make sure the string is held taut but not yet
lifting the lower pulley block. Pull string and
hold. Using the cord stop as a reference, have
another student measure the distance back to
the pulley. Record the length.
If the string is connected to the upper pulley
block a mechanical advantage of 2, 4, or 6 can
be obtained (2, 4, or 6 supporting strings). The
diagram shows a mechanical advantage of 2.
To measure the distance traveled by the lower
pulley block, use the holes in the Physics Stand
as references. They are exactly 5 cm apart.
Equipment Setup
The yellow string is the one you will use to
move the lower pulley block up and down. The
yellow string may have several strands that
support the lower pulley block. These are called
the supporting strands. The red strings are the
safety strings and these hold the bottom block
while you arrange the yellow strings on the
pulleys. The cord stops are used as reference
markers for measuring the length of string
needed to raise the lower block a given
distance.
Step six: Taking measurements
183
Lever
The Lever
Assembly
The Lever is among the most common and
illustrative simple machines. This elegant
apparatus provides a stepping stone to learning
the principles of mechanical advantage, ratios,
equilibrium, and work.
Materials Checklist
Physic Stand Setup.
Step Two: Place thumbscrew through the
Lever
D 1 Hardwood Lever
Slide the thumbscrew through the hole in the
center of the Lever.
D 1 Set of CPO Weights with yellow
string loops
The screw should be inserted from the side of
the Lever that has the scale printed on it.
D 1 Thumb screw
Step Three: Mount the Lever to the
Physics Stand
Select the desired hole in the Physics Stand and
slide the thumbscrew, with the Lever on it,
through the hole. Secure the assembly using the
black plastic knob.
Step Four: Applying Weights
Weights can be applied in a variety of
combinations. The variables are the position
and the number of weights on the lever.
184
To secure the weights to the Lever, slide one
end of a yellow string loop through the hole(s)
in the weight(s). Loop around one edge and slip
the string back through itself. Hang the loop
with weight on the mushroom-shaped slots on
the Lever.
Completed Assembly:
Rollercoaster
Assembly
The Rollercoaster is an excellent tool to
introduce and explore the concepts of energy
and energy conservation. A steel marble rolls
along the specially designed 1.3 meter track.
The Timer and Photogate allow for precise
measurement of the speed of the marble
anywhere
on
the
Rollercoaster.
The
Rollercoaster has printed scale graphics that
represent the distance of travel from the start
position, based upon the marble center point.
This scale also ensures precise placement of the
Photogate.
Step Four: Attaching the Photogate to
the Rollercoaster
Attach the Photogate at the desired position on
the Rollercoaster by turning the metal knob
counterclockwise and sliding the gate onto the
Rollercoaster from the bottom. Now tighten
the metal knob, turning clockwise. Take care to
ensure that the Photogate is flush with the
bottom edge of the coaster (at the chosen
position) or the light beam will not cross the
center of the marble and provide consistent and
accurate measurements.
Materials Checklist
D 1 hardwood Rollercoaster
D 1 Steel marble
D 1 Plastic marble
D 1 Threaded rod with attached black
plastic knob
Physic Stand Setup.
Step Two: Locate the fifth hole on the
Physics Stand
Locate the fifth hole from the base of the
Physics Stand. Slide the threaded rod with black
plastic knob through the hole. The
Rollercoaster will not work properly if it is not
positioned at the fifth hole.
Step Three: Attaching the Rollercoaster
to the Physics Stand
Equipment Setup
The Rollercoaster
Thread the rod into the Rollercoaster at the
end that has the metal insert and the wooden
peg set in the track. Make sure to start
threading on the side that does not have the
scale printed on it.
D 1 Photogate with red or blue wire
185
Step Five: Connecting the Photogate to
the Timer unit
Connect the Photogate to the Timer using a red
or blue wire. Plug the wire in to slot A and be
sure the A button light on the Timer is turned
on. The unit should be set to interval mode.
Timer and photogates refer to the Timer and
Photogates section in Equipment Setup.
Step Six: Rolling the marble
To roll the marble, place the marble directly in
front of the wood peg at the top of the
Rollercoaster. Use this peg to reference an
exact starting place for every roll. Carefully
release the marble taking care not to push the
marble down the track. Now, record the data!
186
Electric Circuits
The Electric Circuits
Materials Checklist
D 1 Electric Circuits Table w/ 12 brass
posts
D 1 Potentiometer
Understanding the Table
The board is a platform for securely assembling
electric circuits. It consists of a solid base with
12 brass posts. The posts are used in making
connections between different parts of the
circuit.
NOTE: The posts are not connected to each
other until the students ‘wire’ them on top of
the board. There is no hidden wiring on the
table.
The table has ‘puzzle-piece’ ends to allow more
than one board to be connected together for
making larger circuits.
D 2 Battery holders
How to Make Connections
D 3 Light bulbs
Connecting wires to posts
D 3 Light bulb holders
Each wire has a circular connector at both ends
called a hoop connector. To add a wire to the
board, just place the hoop around the post and
push down on the hoop. It will slide down the
post, like a jewelry ring over a finger. If you
need to add one or more wires to the post,
simply push the first wire down the post to
make room for another hoop. You can add up
to 4 hoops to a post.
D 4 Short-length wires
D 2 Medium-length wires
D 2 Long-length wires
D 2 Five-ohm resistors
D 1 Ten-ohm resistors
D 2 Knife switches
NOTE: Solid contact is made at any position on
the post. It is not necessary to slide every wire
to the bottom of the post.
D Multimeter (Optional)
Connecting circuit elements to posts
D 1 Twenty-ohm resistor
light bulbs, resistors and switches. Each circuit
element that comes with the Electric Circuits
Set has the same type of hoop connectors as
the wires. To connect a circuit element to a
post just place the hoop on the post and push
down, sliding it down the post.
A Sample Circiuit
Connecting wires, elements and posts
A circuit is made when wires and elements are
connected together making a path for
electricity. Below is an example of a simple
circuit with a battery, a light bulb and some
wires.
Equipment Setup
The Electric Circuits Set is a powerful tool for
understanding how electricity works in circuits.
Students are able to perform experiments that
explore the concepts of voltage, current, and
resistance in simple circuits. The design of the
board and accessories allows the students to
connect circuits that clearly match their
diagrams. The connectors are easy to assemble,
making positive contact for total conduction of
current.
What to do with the Electric
Circuits Table
A circuit element is any item that uses or affects
electricity in a circuit. This includes batteries,
187
Electric Motor
The Electric Motor
The Permanent Magnets
The Electric Motor is designed with inquiry
based learning in mind. Students can learn how
a motor works and use what they have learned
to build and test motors of different
configurations. Magnetism, permanent and
electromagnets, electric circuits, current and
voltage, series and parallel circuits, electrical
machines, efficiency and rotational motion are
just some of the topics that can be explored
using the Electric Motor.
Motors work by using magnetic forces to push
and pull on other magnets. Two kinds of
magnets are used in the Electric Motor.
Permanent magnets create their own magnetic
fields without electricity being supplied. There
are 12 small ceramic permanent magnets
supplied with the Electric Motor. These magnets
have two poles. Magnetic poles follow the rules:
Materials Checklist
For example putting two north poles facing
each other will cause the magnets to repel each
other. The magnets that come with the motor
have the north and south poles on the faces
rather than the ends (see drawing below).
There are red and white stickers on the
magnets to identify the north and south poles.
D 5 Switching discs
D 1 Hardwood Electric Motor unit
D 1 Electromagnet unit
D 1 Generator coil unit
The Right Hand Rule
When the fingers of your right hand curl in the
direction of the current, your thumb points in the
direction of the magnetic field.
“Like repels like,” and
“Unlike poles attract.”
D 1 Battery pack
D Rubber bands
D 12 Ceramic magnets
D 1 Multimeter (not included)
D Timer kit (for one exercise)
The Electromagnets
Electromagnets use electric current to make the
magnetic field. The simplest electromagnet uses
a coil of wire, often wrapped around some iron
or steel. The coil of wire creates a magnetic
field, just like a bar magnet. The iron or steel
amplifies the magnetic field created by the
current in the coil. When current flows through
the coil, the steel core becomes a magnet which
188
is stronger than the coil alone. The location of
the north and south poles depends on the
direction of the electric current.
The electromagnet units that come with the
motor have an “electric eye” switch that is used
to change the direction of the current flowing in
the coil of wire. LED's on the top of the magnet
that indicate where the north pole is. When the
electric eye is not blocked (see diagram on the
next page) the current flows in a direction such
that the north pole of the magnet is at the front
end of the electromagnet module. Blocking the
beam causes the electronics in the module to
reverse the direction of the current, putting the
north pole at the back end, and the south pole
at the front.
the white plastic thumb nuts (just a little) to
move the electromagnet modules.
The electromagnet modules push and pull on
the magnets in the rotor and make the motor
spin. We know that the electromagnets must
switch north and south poles every time a
magnet passes by to make the rotor keep
spinning in the same direction. Making this
happen at the right place on the rotor is what
the switch plates are for.
Equipment Setup
The Electric Motor is technically a brushless DC
permanent magnet design. The optical switch in
the electromagnet module allows the current to
be reversed without needing brushes or
commutator. This technology reduces friction
and makes it possible to build many different
motor designs on the same chassis. From 2 to
12 permanent magnets and 1-6 electromagnets
can be combined to make a working motor.
The picture below shows the rotor with the
switch plate off. Use an extra magnet or the big
nut or anything else magnetic to pull the
magnets out.
The Switching Discs
The rotor in the Electric Motor has places
where you can put up to 12 magnets. You can
get to the magnets by taking off the big nut on
the shaft and lifting off the switch plate. The
picture below shows where things are. The
electromagnet modules have to be removed (or
slid back) to get the switch plate out. Loosen
189
Find the four pole switch plate. This one has
two black sections and two clear sections
around the outer rim. We call the pink plate a 4
pole switch because there are four places
around the rim where there is a transition from
black to clear. This disc makes the
electromagnet reverse directions four times for
each rotation of the rotor.
Timing the Motor
To make a working electric motor with the 4
pole switch plate you will need 4 magnets. The
magnets should be arranged so that the north
or south poles alternate as shown in the
diagram below. The alternation is necessary so
that the electromagnets can pull then push each
successive magnet in the rotor with the fewest
number of switching cycles.
190
Remember that the electromagnet must switch
as the magnet passes by. The motor will work
best when the electromagnet switches in the
right place relative to the magnets in the rotor.
Notice that there is a degree scale printed on
the rotor with a circular window so you can see
the magnets in the rotor. This scale allows you
to tune the motor for maximum speed by
adjusting the position of the switch plate. Finger
tighten the big nut to secure the switching disc
once you have selected a position. A good
starting point is to have the switch (the point at
which clear meets black) positioned right in the
middle of the ceramic magnets as shown in the
diagram below.
With the switching disc snug under the nut, and
the four magnets aligned with the clear/black
transitions the motor should be ready to work.
To make the electrical connections the modules
must be pushed all the way forward and the
white nylon thumb nuts tightened finger tight. It
might be necessary to lift the electromagnet
module slightly to rest on top of the small brass
terminal rings that stick up from the wooden
base. Do not over-tighten the thumbnuts, only
slight pressure is required to make electrical
contact.
Connect the battery pack with the positive
(red) and negative (black) wires in the
corresponding positive (+) and negative (-)
sockets on the motor. Push the RUN button
and see what happens. You may have to give
your motor a spin to get it started.
Equipment Setup
There are 5 different switch plates. This means
there are several different designs of motors
that can be built. Not all will work!!! We
intentionally made one plate (the 8 pole) that
does not work well because it requires 8 evenly
spaced magnets and there are only 12 spaces.
Eight can not be factored into 12 evenly so the
students will have a tough time making the 8pole switch plate work. The diagrams on the
next page show the configuration for several
working variations. For most designs the motor
will spin (slowly) with a single electromagnet.
The diagrams below show the configuration for
several working variations.
timer and photogates refer to the timer and
photogates setup.
191
Pendulum
The Pendulum
Assembly
This simple pendulum is an ideal tool for
teaching and learning the basic concepts of
harmonic motion. The concepts of cycle,
period, frequency and amplitude are intuitively
illustrated. Students can change three variables:
the length of the string, the weight of the
swinging bob, and the amplitude (angle) of the
swing. The Pendulum has a 7” hardwood face
with angle scale graphics for easy determination
of amplitude. The length of the string can be
varied from 15 cm to nearly 1 meter. Used with
the Timer and a Photogate, the Pendulum will
provide precise measurements of period.
Materials Checklist
Thread the rod with the knob into the back of
the Pendulum face, securing the unit to the
Physics Stand.
Physic Stand Setup.
Step Two: Select the desired hole in the
Physics Stand
Slide the threaded rod with black plastic knob
through the desired hole in the Physics Stand.
Step Three: Secure the Pendulum face to
the Physics Stand
D 1 Hardwood Pendulum face
D 1 String and bob assembly
D 10 Washers (masses)
D 1 Threaded rod with attached black
plastic knob
D 1 Photogate with red or blue wire
Step Four: Attach the swinging bob
Select the length of string for the swinging bob
by sliding the string into the slot in the peg on
the Pendulum face. Check the length of the
string by measuring from the bottom of the
slotted peg to the bottom of the stack of
washers on the swinging bob. The washers can
192
be used to add or subtract weight from the
swinging bob.
Step Five: Mount the Photogate on the
Physics Stand and align the Photogate
with the swinging bob
To mount the Photogate to the stand, open the
gate by turning the aluminum knob counter
clockwise. Place the outer edge of the gate
against the pole and tighten the aluminum knob
to pinch the pole between the outer edge of the
gate and the aluminum knob. A slight tilt is
necessary for the wire of the gate to clear the
pole.
Step 6: Setting up the Timer II with the
Pendulum
Attach the Photogate to slot A in the Timer
using the red or blue wire. Be sure the “A” light
is on and that the Timer has been set to period
mode.
Equipment Setup
Be sure to align the 2 small holes in the gate
with the center of the round portion of the
swinging bob.
Timer and Photogates refer to the Timer and
Photogates section in the Equipment Setup.
193
Sound & Waves Generator
The Sound & Waves Generator
Experiments with the Sound & Waves
Generator open up fascinating questions for
hands-on exploration. This piece of equipment
has a sound synthesizer that can make pure
tones at frequencies ranging from 20 to 25,000
Hz. The wave generator, also know as the
wiggler, can create standing waves on a string.
Materials Checklist
D 1 Wiggler (motor)
D 1 Fiddle head
D 1 Sound & Waves console
D 1 Blue or red phone cord
D 1 Black phono wire
D 1 Elastic (wiggler) string
D 2 Black plastic knobs
D 2 Speakers
194
Assembly for Standing Waves on a
String
be set up) by following the instructions on
setting up the Physics Stand.
Step two: Attach the wiggler and fiddle
head to the Physic Stand
Attach the wiggler to the Physics Stand by
placing the threaded rod and peg on the wiggler
through the bottom two holes on the stand.
Secure the wiggler by screwing a black plastic
knob onto the threaded rod as it comes
through the hole on the stand. Attach the fiddle
head to the Physics Stand by placing the
threaded rod and peg on the head through the
top two holes on the physics stand, as with the
wiggler. Be sure the black knobs for each piece
are on the same side of the pole. The top of
the fiddle head will be higher than the Physics
Stand pole when it is set up.
Step three: Attach the string to the
wiggler
The wiggler arm is a narrow metal strip shaped
like an arrow. The tip of the wiggler arm
protrudes from the wiggler about 2 cm. If the
string is not already attached to the wiggler,
locate the hole in the wiggler arm and thread
the elastic string through the hole. Knot the
string at the end. This knot will create a stop so
that the string can be pulled tight.
Step four: Attach the string from the
wiggler to the fiddle head
Attach the free end of the string to the fiddle
head by pulling it to the top knob on the fiddle
head. At this point there should be no slack in
the string. Now tighten the string by stretching
it a little (5-10 cm). Then, wrap the end around
the back of the knob - sliding it between two of
the washers. Lightly tighten the black plastic
knob, securing the string between the washers.
Step seven: Adjust the frequency of the
string wiggler and sound generator
Assembly for Sound
Turn on the Timer and set to frequency mode.
Plug one end of the phone cord into the in the
square socket on the Sound and Waves (S&W)
console. Plug the other end into the A slot on
the Timer. Ensure that the A light is illuminated
on the Timer. Pressing the button on the S&W
console, change the mode to wave (wiggler). A
light indicates to which mode the unit is set.
Use the dial on S&W console to adjust the
frequency. The display window of the Timer
shows the frequency of the wiggler (if set up in
wave mode) or the tone from the speakers (set
in sound mode). The frequency is shown in
units of hertz (Hz).
Step One: Connect the Timer to the
Sound & Waves console
NOTE: See picture in step six
Step six: Connect the wiggler to the S&W
console
Connect one end of the black wire to the S&W
console in the circular phono socket (jack). The
jack is located on the top edge of the console.
Then connect the other end to the into the
bottom of the wiggler.
Step eight: select activities for the
students
Refer to the Sound & Waves and Light & Optics
volume of the Teacher’s Guides for activity
instructions and to the instruction manual for
more information.
Turn on the Timer and set to frequency mode.
Plug one end of the phone cord into the in the
square socket on the Sound and Waves (S&W)
console. Plug the other end into the A slot on
the Timer. Ensure that the A light is illuminated
on the Timer. Pressing the button on the S&W
console, change the mode to wave (wiggler). A
light indicates to which mode the unit is set.
NOTE: See picture in step six of Assembly for
Standing Waves on a String
Step two: Connect the speakers to the
S&W Console
Equipment Setup
Step five: Connect the Timer to the
Sound & Waves console
Connect the end of the wire from the speakers
to the S&W console in the circular phono
socket (jack). The jack is located on the top
edge of the console.
195
CPO Optics Kit
The Optics Kit
What to Do with the Optics Table
The Optics Kit is a unique tool that enables
students to see how light travels through the air
and other media. By using laser light, one can
clearly demonstrate and understand the rules
that light follows as it moves from a source to a
receiver. Students can observe the effects of
lenses and mirrors, prove the laws of refraction
and reflection, and see how color relates to
light.
Understanding the table
Materials Checklist
Place a single sheet of graph paper down on the
table so that it lines up with the white inlay
sheet. To secure the graph paper, place a
magnetic strip along each of the long edges of
the paper.
D 1 Optics Table
D 1 Laser module
D 3 Bright white LED Modules with
colored filters (red, green , blue)
D 1 Circuitry box for connecting up to
5 modules
The table is a platform for arranging the optic
elements and graphing the path of light as it is
affected by these optical elements. It consists of
a solid base with a metallic inlay sheet for
positioning the elements, which have magnetic
bases.
Setting up the graph paper
How to Connect the Light
Modules
D 1 Six Volt UL approved power transformer
D 1 Triangular prism (45o - 45o - 90o)
D 1 Convex lens
D 1 Plane mirror
D 5 Diffraction grating glasses
D Graph paper (11” x 17”) Purchased
separately.
D 2 Magnet strips for securing the
graph paper
D Optional- Spectrometer
196
The other end of the power adapter plugs into a
standard 120 volt electric wall outlet. Make
sure that the ON/OFF switch on the circuitry
box is in the OFF position before plugging
adapter into a wall outlet.
Connecting the circuitry box
The circuitry box has 6 circular sockets (jacks)
on one side. One of the jacks is labeled DC
INPUT. The other jacks are numbered (1 to 5).
The power adapter that comes with the kit has
a circular plug at one end. Place this plug in the
jack that is labeled DC INPUT.
Connecting light modules to circuitry box
Each of the light modules that comes with the
Optics Kit has a light source on a magnetic base
at one end of a wire and a small phono plug at
the other end. Push the plug into any numbered
jack on the circuitry box. You can now move
the circuitry box switch to the ON position and
the light module will come on.
Spectrometer
Procedure
The Project STAR Spectrometer allows
students to measure the wavelengths of visible
light. By using the process of diffraction, it
breaks light into a visible spectrum. A scale
allows the user to quantitatively assign values to
the specific spectrum being viewed. Different
light sources produce different spectrums.
Step one: Proper usage
Materials Checklist
D 1 Spectrometer
D 1 Incandescent light bulb (bulb with
a glowing filament)
D Pencil or pen or an object with a
dull point
D A white surface such as a movie
screen, wall or large piece of construction paper
UNDER NO CIRCUMSTANCES SHOULD
ANY PERSON USING THE SPECTROMETER
LOOK DIRECTLY AT THE SUN! DOING SO
CAN CAUSE PERMANENT AND SERIOUS
DAMAGE TO THE EYES! WHEN LOOKING
AT THE SOLAR SPECTRUM USE WHITE
SURFACES OR CLOUDS TO REFLECT THE
LIGHT SOURCE INTO THE SPECTROMETER.
Hold the Spectrometer so that the printed side
is facing upward. In a well lit room, hold the
Spectrometer so that one eye is looking into
the diffraction grating (with the other eye
closed) and the light intake is pointing directly at
a fluorescent light source. You should be able to
see a scale inside as you look slightly to the left
of the light intake. You should also notice colors
at various places inside the spectrometer.
Step two: Calibrating the Spectrometer
Notice that the plastic disk with the attached
diffraction grating can be slightly rotated.
Looking into the Spectrometer, you will notice
that the colors move as you rotate the disk.
Rotate the disk until you see the colors in a
horizontal line between the two rows of
numbers on the scale.
Again, point the Spectrometer at fluorescent
light source. Using the dull-point object, adjust
the scale until the green line is aligned with the
mark at 546 nm. Adjust by placing the tip of the
dull pointed object into the hole for the scale
adjustment. Slide the adjustment into desired
position.
Equipment Setup
The Project STAR Spectrometer
For detailed activity instructions refer to your
“Activities for the Spectrometer” manual.
197
Displacement Tank
The Displacement Tank
Using the Displacement Tank
The displacement tank is designed to enable
students to accurately measure the volume of
irregular objects. The tank also helps visual
learners to grasp the concepts of buoyancy and
Archimedes’ principle.
Place a disposable cup under the spout.
Carefully fill the tank until the water begins to
drip out of the spout. When the water stops
flowing, discard the water collected in the
disposable cup.
Materials Checklist
Set the cup aside and place a beaker under the
spout. Gently place the object to be measured
into the displacement tank. It is important to
avoid splashing the water or creating a “wave”
which would cause extra water to flow out of
the spout. Students may need to practice once
or twice to establish a consistent technique.
D 1 Displacement Tank
D Water source (sink or pitcher)
D 1 Disposable cup
D 1 Beaker
D 1 Graduated cylinder
D Sponges or paper towels
D Objects to be measured
When the water stops flowing out of the spout,
it can be poured from the beaker into a
graduated cylinder for precise measurement.
The volume of the water displaced will be equal
to the volume of the object that was placed in
the tank. Remember that the tank must be
refilled after each use.
If your spout is equipped with an on/off
handle:
Fill the tank as directed above. After the water
has stopped flowing from the spout, turn the
handle to the off position. Place the object in
the tank. After any “waves” have settled, open
the spout and allow the water to flow into the
beaker. Measure as directed above.
Trouble shooting
Occasionally, when a small object is placed in
the tank, no water will flow out of the spout.
This happens because an air bubble has formed
in the spout. Simply tap on the spout with a
pencil to release the air bubble.
198
Atom Building Game
Atom Building Game II
Materials Checklist
D 1 ABG board
D 1 Tube red marbles (protons)
D 1 Tube blue marbles (neutrons)
D 1 Tube yellow marbles (electrons)
D 2 Periodic tables
The ABG board is designed to sit on a table top
with four students (or teams) positioned
around the board. Each team has a pocket of
marbles and use of a periodic table. Make copies
of the laminated tables as necessary.
Make sure that each team has an equal number
of each kind of marbles in their pocket.
Identifying the Parts of the ABG
The center of the board with over 100 dimples
represents the nucleus. This is where the
protons and neutrons are to be placed during
the activities. The steps around the nucleus
represent the energy levels of the s, p, and d
orbitals for electron shells 1-5. The red marbles
represent protons. The blue marbles represent
neutrons and yellow marbles represent
electrons.
Electron Shells
D 1 Deck of Nuclear Reactions cards
Nucleus
Reading the Periodic Table
The periodic table is used for two of the three
games that can be played using the ABG.
Students should be familiar with what the
different numbers and symbols mean.
6, 7
Li
3
Mass Numbers
of Isotopes
Element Symbol
Atomic Number
Atomic Number: The atomic number is the
number of protons (red marbles) in the nucleus.
The atomic number determines what element
the atom is.
Equipment Setup
The Atom Building Game II (ABG II) is an
illustrative, multi-level model that allows
students to build atoms with colored marbles
that
represent protons, neutrons, and
electrons. This model is a powerful tool for
helping students understand the atom and
different chemical properties of the elements.
Activities stimulate learning about atomic
structure, electron shells, chemical bonding,
isotopes, energy levels, emission spectra, and
even lasers.
Design of the Atom Building
Game II
Mass Number: The mass number is the total
number of particles (protons and neutrons) in
the nucleus.
Isotopes: Isotopes are atoms with the same
number of protons but different mass numbers
(protons plus neutrons). The mass numbers on
the periodic tables provided with the ABG are
stable isotope mass numbers.
D 1 Deck of Photons & Lasers cards
D 1 Game booklet
Selecting Activities
Marble Pocket
For the rules of the games and more
information about the ABG refer to the detailed
instruction guide that accompanies the
equipment or to the Teacher’s Guides.
199
Periodic Table Tiles
The Periodic Table Tiles
Design of the Periodic Table Tiles
Reading the Periodic Table
The Periodic Table Tiles include 164 colorcoded, foam tiles. There are ten colors in total.
Each group of elements has its own color on
one side of the tiles. The transition metals, and
Lanthanide and Actinide series all share a single
color. The reverse side of the tiles are yellow
and contain extra elements that are commonly
used when building compounds and balancing
chemical equations. Students can also use the
tiles to participate in such learning games as
Molecular Crossword and Element Bingo.
The Periodic Table Tiles are designed so that
students can work with elements and chemical
equations on a desk top.
The special laminated periodic tables are used
with most of the activities. These tables show
the known oxidation states for the elements. In
the example below the element iron has two
possible oxidation states, +3 and +2. These
numbers mean that iron atoms will form
molecules in which each iron atom gives up two
or three electrons. Usually one state is more
stable than the others and is shown in bold
typeface. For iron the +3 oxidation state is
more stable. The laminated periodic tables help
students become familiar with the symbols and
oxidation states of the elements.
Materials Checklist
D 164 color-coded tiles
D 2 Laminated Periodic Tables
D 2 Hydrogen bonding rules cards
D 1 Game booklet
The colors allow quick identification of the
elements. More importantly, they reinforce the
grouping of the elements. Below is a list of the
each and its corresponding color:
Oxidation state
+3,+2
Fe
Element symbol
26
Atomic Number
Iron
Selecting Activities
Refer to the detailed instruction guide for more
information about the Periodic Table Tiles, as
well as, instructions for activities and games that
use the Periodic Table Tiles. Instructions for
how to use the tiles are also provided in the
chemistry volume of the Teacher’s Guides.
200
A
amperes – the unit for measuring electrical current; the
abbreviation is amp.
amplitude – the maximum distance from the average in
harmonic motion; amplitude is often a distance or an angle.
acid – a chemical that contributes hydrogen ions, H+, to a
solution.
acid precipitation – rain, snow, or fog that has a pH lower
than 5.6.
aquifer – an underground area of sediment and rocks where
groundwater collects.
acid rain – rain that has a pH lower than 5.6.
acoustics – the science and technology of sound.
addition reaction – a chemical reaction in which two or more
substances combine to form a new compound.
additive primary colors – red, green, and blue.
air friction – the opposing force created by objects moving
through air.
albedo – the percentage of the sun’s light reflected from a
planet’s surface.
alloys – solutions of two or more metals.
alpha decay – radioactive decay that results in an alpha particle
(a helium nucleus) being emitted from the nucleus of a
radioactive element.
alpha particles – a partially charged particle emitted from the
nucleus of an atom during radioactive decay; also called a
helium nucleus.
alternating current – an electric current that reverses its
direction at repeated intervals; the abbreviation for this
is AC.
anhydrous – means “without water”; describes the state of a
hydrate that has lost water through evaporation.
Glossary
absorbers – objects that have the ability to absorb radiant
energy.
accelerate – to increase speed or change direction.
acceleration – the change of speed over time.
Archimedes’ principle – a principle that states that the force
exerted on an object in a liquid is equal to the weight of the
fluid displaced by the object.
atmospheres – the unit used to measure atmospheric pressure;
the abbreviation is atm.
atom – the smallest particle of an element that can exist alone
or in combination with other atoms.
atomic mass – the average mass of all the known isotopes of
an element.
atomic mass unit – defined as the mass of 1/12 of a carbon-12
atom (6 protons and 6 neutrons in the nucleus plus 6
electrons outside the nucleus).
atomic number – the number of protons that an atom contains.
atomic theory – a theory that states that all matter is composed
of tiny particles called atoms.
average speed – how fast something moves over a certain
distance.
Avogardo’s number – the number of atoms in the atomic mass
of an element, or the number of molecules in the formula
mass of a compound when these masses are expressed in
grams.
509
B
balance – occurs when the number and type of atoms on the
reactant’s and product’s sides of a chemical equation are
equal.
base – a chemical that contributes hydroxyl ions, OH-, to a
solution.
battery – a device that uses chemical energy to move electrical
charges.
beat – a rapid alteration between loudness and silence.
beta decay – radioactive decay that results in a beta particle (an
electron) being emitted from the nucleus of a radioactive
element.
calorie – the quantity of heat required to raise the temperature
of one gram of water by 1°C.
carbohydrate – a nutrient molecule composed of simple or
complex sugars; it contains four calories of energy per
gram.
carbon dating – a technique to find out how old something is;
the measure of carbon-14 in a sample that is between a few
thousand and 50,000 years old.
cause and effect – the relationship between an event that brings
about a result and what happens due to the result.
beta particles – a negatively charged particle (an electron)
emitted from the nucleus of an atom during radioactive
decay.
Celsius scale – a temperature scale on which zero equals the
temperature that water freezes (0°C) and 100 is the
temperature that water boils (100°C) where C stands for
Celsius.
binary compound – a covalent compound that consists of only
two types of elements.
Charles’ law – the volume of a gas increases with increasing
temperature if pressure is held constant.
Boyle’s law – pressure and volume are inversely related.
chemical bond – an attraction between two or more different
atoms that binds them together.
British thermal unit (Btu) – the quantity of heat it takes to
increase the temperature of one pound of water by 1°F. One
Btu is equal to 1,055 joules or 252 calories.
brittleness – a measure of a material’s tendency to shatter upon
impact.
buoyancy – a measure of the upward force a fluid exerts on an
object.
buoyant convection– see natural convection.
510
C
chemical change – a change in a substance that involves the
breaking and reforming of chemical bonds to make a new
substance or substances.
chemical energy – a type of energy stored in molecules.
chemical equation – chemical formulas and symbols that
represent a chemical reaction.
chemical formula – a representation of a compound that
includes the symbols and numbers of atoms in the
compound.
chemical potential energy – the energy that is stored in
chemical bonds.
chemical symbol – an abbreviation that represents the name of
an element; used in chemical formulas.
circuit – see electric circuit.
circuit diagram – the diagramatic representation of an electric
circuit.
circular waves – waves that move in concentric circles.
closed circuit – a circuit in which the switch is turned to the
“on” position, causing there to be no breaks anywhere in the
wire.
cochlea – a tiny, fluid-filled bone structure in the inner ear with
three tubes and a spiral.
coefficient –a number placed in front of a chemical formula to
make the number of atoms on each side of a chemical
equation equal.
colloid – a type of mixture in which the particles (atoms or
molecules) are between 1.0 and 1,000 nanometers in
diameter.
combustion reaction – a reaction in which a substance
combines with oxygen, releasing large amounts of energy
in the form of heat and light.
compounds – substances made of two or more elements that
cannot be separated by physical means.
compression stroke – in a four-stroke engine, the stroke in
which the fuel and air are compressed and ignited by a
spark plug.
condensation – the process by which a substance in its gaseous
state loses energy and enters its liquid state; one phase in
the water cycle.
conduction – the transfer of thermal energy by the direct
contact of particles of matter.
Glossary
chemical reaction – the breaking of bonds to form new
substances (called the products); atoms are rearranged in a
chemical reaction.
conceptual model – a written description or diagram based on
ideas and observations that are used to describe how a
process or object works; Sir Isaac Newton’s law of
universal gravitation is a conceptual model.
cone cells – photoreceptor cells in the retina of the eye that
respond to color.
conservation of atoms – principle that states the number of
each type of atom on the reactant’s side must be equal to the
number of each type of atom on the product’s side of a
chemical equation.
consonance – a combination of sounds that is harmonious or
agreeable.
constructive interference – occurs when waves add up to
make a larger amplitude.
continuous – connected to itself.
controlled experiment – when one variable is changed and all
the others are controlled or stay the same throughout the
experiment.
controlled variables – variables in an experiment that are kept
the same throughout the experiment.
convection – occurs when hot air rises upward due to a
decrease in density, and then expands, giving off heat.
converge – to bend light so that the rays come together.
511
converging lens – a type of lens that bends light so that the
parallel rays coming in bend toward the focal point.
destructive interference – occurs when waves add up to make
a smaller amplitude.
coulomb – the unit for electrical charge.
dew point – the temperature at which air becomes saturated
with water.
covalent bond – a type of chemical bond that is formed when
two atoms share electrons.
covalent compound – a compound that consists of atoms that
are covalently bonded.
crest – the high point on a wave.
diffraction – the process by which waves can bend around
corners or pass through openings.
critical angle – the angle at which light is totally reflected back
into a material.
direct current – electrical current flowing in one direction
only; the abbreviation is DC.
current – the quantity that refers to the rate of flow of electric
charges; current is measured in amps.
dissolution reaction – a reaction that occurs when an ionic
compound dissolves in water to make an ionic solution.
cyan – a greenish, light-blue that is created when red is
absorbed and blue and green are reflected.
dissolved – the state in which solute particles are evenly
distributed throughout a solvent.
cycle – a unit of motion that repeats over and over.
D
dissolving rate – the length of time it takes for a certain amount
of solute to dissolve in a solvent; the dissolving rate can be
changed by changing the temperature, or by physical means
such as by stirring a solution.
deceleration – occurs when change in speed, or acceleration,
is in the negative direction.
dissonance – a combination of discordant or unsettling sounds.
decomposition reaction – a chemical reaction in which a
single compound is broken down to produce two or more
smaller compounds.
diverge – bending light so that the rays spread apart.
density – a property that describes the relationship between
mass and volume.
dependent variable – the variable in an experiment that
changes in response to choices made by the experimenter;
this variable is plotted on the y-axis of a graph.
512
diatomic molecules – a molecule that has only two atoms of the
same element.
distance – the length of space between two points.
diverging lens – a type of lens that bends light away from the
focal point.
double-displacement reaction – a reaction in which ions from
two compounds in a solution exchange places to produce
two new compounds.
E
elasticity – a measure of a solid’s ability to stretch and then
return to its original shape and size.
electric circuits – the structures that provide paths through
which electricity travels.
electric motor – a device that uses electricity and magnets to
turn electrical energy into rotating mechanical energy.
electrical conductivity – the ability of a material to conduct (or
carry) electricity.
electrical conductor – a material that easily carries electrical
current.
electromagnetic induction – the creation of electric current
when a magnet is moved inside a loop of wire; generators
are devices that work using electromagnetic induction.
electromagnetic spectrum – the whole range of light
(electromagnetic radiation).
electron – a subatomic particle in an atom that is negatively
charged and that occupies the energy levels in an atom;
electrons are involved in chemical bonds and reactions.
electronegativity – the attraction an atom has for the shared
pair of electrons in a chemical bond.
electrical energy – another term for electricity.
electroscope – an instrument that is used to detect charged
objects.
electrical force – the force that charged materials or objects
exert on each other.
elements – substances that contain only one kind of matter.
electrical insulator – a material that poorly conducts current.
electrical symbols – simple symbols used in circuit diagrams.
electrically charged – an object that has an excess amount of
either positive or negative charges.
electrically neutral – an object that has equal amounts of
positive and negative charges.
electrolytes – chemicals that form ions and conduct current
when dissolved in water.
electromagnet – a strong, short-lasting magnet that can be
made by inserting iron into a wire coil that is conducting an
electric current.
Glossary
efficiency – the ratio of a machine’s output work to input work.
electromagnetic force – the force that exists between electric
charges; often described as electrical force or magnetic
force depending on how charges interact.
emissions – the airborne gases and particles expelled through
an operating automobile’s tailpipe.
emitters – objects that have the ability to emit radiation
efficiently.
endothermic reaction – a reaction in which more energy is
required to break the bonds in reactants than is released
from the formation of new bonds in the products.
energy – a fundamental building block of the universe; it
appears in different forms (i.e., position, motion, or heat)
and can travel in different ways (i.e., light, sound, or
electricity).
energy level – a region around the nucleus of an atom where
electrons are most likely to be found; only a certain number
of electrons can be found in each energy level of an atom.
513
energy transformation – the conversion from one kind of
energy to another kind of energy; for example, an energy
transformation occurs when potential energy is converted
to kinetic energy.
engineering – the application of science to solve technical
problems.
engineering cycle – a process used to build devices that solve
technical problems. The four steps of the engineering cycle
are creating a design, building a prototype, testing the
prototype, and evaluating test results.
engineers – people who design technology to solve problems.
English system – a system of measuring that uses, for example,
distance units of inches, yards, and miles.
equilibrium – (1) in physics, occurs when the forces on an
object are balanced; (2) in chemistry, the state in which the
solute in a solution is dissolving and coming out of solution
at the same rate.
external combustion engine – a machine in which the action of
heating takes place outside it, as in a steam engine.
F
Fahrenheit scale – a temperature scale on which water freezes
at 32 degrees Fahrenheit (or 32°F) and water boils at 212°F.
fat – a nutrient molecule that is composed of carbon and
hydrogen atoms, and that contains 9 grams of energy per
gram.
first law of thermodynamics – states that energy in a closed
system is conserved.
fission – a nuclear reaction that involves the splitting of the
nucleus of an atom.
evaporation – the process by which a substance in its liquid
state gains energy and enters its gaseous state; one phase of
the water cycle.
fluorescent – a type of electric light bulb.
excess reactant – a reactant that is not completely used up.
focal point – the point at which light rays meet after having
entered a converging lens parallel to the principal axis.
exhaust stroke – in a four-stroke engine, the stroke in which a
valve opens and releases exhaust gases.
exothermic reaction – occurs when less energy is required to
break the bonds in reactants than is released when bonds are
formed to make new products.
experiment – any situation that is set up to observe and
measure something happening.
experimental technique – the exact procedure that is followed
each time an experiment is repeated.
514
experimental variable – a variable in an experiment that is
changed by the experimenter; the experimental variable is
plotted as an independent variable on the x-axis of a graph.
focal length – the distance from the center of a lens to the focal
point.
focus – the place where all the light rays that have come from
an object meet to form an image after having passed
through a converging lens.
force – a push, a pull, or any action that has the ability to
change motion.
forced convection – occurs when mechanical means is used to
force fluid or gas to move.
fossil fuels – hydrocarbon substances including oil, coal, and
natural gas that are extracted from the Earth; fossil fuels are
used as the primary source of energy in the United States.
free fall – the acceleration of a falling object under the
influence of the Earth’s gravitational force.
frequency – (1) in harmonics, the number of cycles an
oscillator makes per second; (2) in waves, the number of
wavelengths that pass a given point in one second.
two variables on a graph so that the relationship is easily
seen and understood.
gravity – the attractive force that exists between any two
objects that have mass.
groundwater – water that collects underground in an aquifer;
this water supplies wells and springs.
group of elements – elements that exhibit similar chemical
properties; arranged in columns on the periodic table.
H
friction – the force that results from relative motion between
objects (like the wheel and axle of a car).
half-life – the length of time it takes for half an amount of
radioactive substance to undergo radioactive decay.
fulcrum – a fixed point on a lever.
hardness – measures a solid’s resistance to scratching.
fundamental – the name of the first harmonic.
harmonic motion – motion that repeats itself.
fusion – a nuclear reaction that involves fusing nuclei from two
atoms to make a different atom.
harmonics – (1) frequencies that are multiples of fundamental
notes; (2) multiples of natural frequency.
G
heat – a flow of thermal energy from one object to another
object due to a temperature difference.
gamma ray – a photon emitted spontaneously by a radioactive
substance.
heat transfer – the transfer of energy in the form of heat from
a material at a higher temperature to a material at a lower
temperature.
gear – a wheel with teeth; two or more gears can be connected
together to change the speed and/or direction of rotating
motion.
heat-temperature rule – a rule stating that the more heat you
add to an object the greater the increase in temperature.
generator – a combination of mechanical and electrical
systems that converts kinetic energy into electrical energy.
global warming – an increase in the Earth’s temperature due to
increased carbon dioxide in the atmosphere.
graphical model – a model that shows the relationship between
Glossary
formula mass – determined by adding up the atomic mass units
of all the atoms in the compound; a way to compare the
masses of molecules of different compounds.
hertz – a unit of one cycle per second used to measure
frequency; the abbreviation is Hz.
heterogeneous mixture – a mixture in which every sample of
it might have a different composition.
515
homogeneous mixture – a mixture in which every sample of it
has the same composition.
index of refraction – a ratio that tells how much the speed of
light is reduced when it passes through a material.
horsepower – a unit of power; one horsepower is equal to 746
watts.
inertia – the reluctance of a body to change its state of motion.
humidity – a measurement of how much water vapor is in the
air.
hydrate – a compound that has water molecules chemically
bonded to its ions.
hydrated – combined with water or the elements of water.
hydrochloric acid – a highly acidic substance your stomach
normally produces to help you break down food.
hydrogen bond – a weak bond between the partially charged
positive end of one water molecule and the partially
charged negative end of another water molecule.
hydrologic cycle – describes how water moves around the
Earth by the processes of evaporation, condensation,
precipitation, and transpiration.
hypothesis – a prediction that can be tested by
experimentation.
I
516
image – a picture of an object that is formed using a mirror or
lens where light rays from the object meet.
incandescence – the process of making light with heat.
incident ray – the ray that comes from an object and strikes a
surface.
independent variable – the variable in an experiment that is
manipulated by the experimenter and that causes changes in
the dependent variable in the experiment; this variable is
plotted on the x-axis of a graph.
infrared light – electromagnetic radiation, including heat, with
wavelengths longer than the visible spectrum.
input – includes everything you do to make a machine work.
input arm – when you place a lever on a fulcrum, the input arm
is the side of the lever where the input force is applied.
input force – the force applied to a machine.
insoluble – a term to describe a substance that does not dissolve
in water.
instantaneous speed – the speed of an object at a specific point
in its journey.
intake stroke – in a four-stroke engine, the stroke in which air
and fuel enter the cylinder.
internal combustion engine – a machine in which the burning
process takes place inside the cylinder (the container
holding the piston).
investigation – one or more experiences that are all connected
to answering the same basic question.
ion – an atom that has an electrical charge.
ionic bond – a type of chemical bond between atoms that
gained or lost electrons; a bond between ions.
ionic compound – a compound that is made up of ions.
isotopes – forms of the same element that have different
numbers of neutrons and different mass numbers.
J
K
kilocalories – the amount of heat required to raise the
temperature of one kilogram of water 1°C; the abbreviation
for this is kcal.
kilowatt – a measurement equal to 1,000 watts or 1,000 joules
per second.
kilowatt-hour – indicates that a kilowatt of power has been
used for one hour.
law of conservation of momentum – states that as long as
interacting objects are not influenced by outside forces (like
friction), their momentum before the interaction will equal
their momentum after the interaction.
law of universal gravitation–The force of attraction between
two objects is directly related to the masses of the objects
and indirectly related to the distance between them.
length – a unit of measurement for distance.
lens – a shape of a transparent material, like glass, that is used
to bend light rays.
lever – a stiff structure that rotates around a fixed point called
the fulcrum.
kinetic energy – energy that comes from motion.
limiting reactant – the reactant that is used up first in a
chemical reaction.
Kirchhoff’s current law – states the current into a branch in a
circuit equals the amount of current out of the branch.
longitudinal wave – a wave whose oscillations are in the same
direction as the wave moves.
Kirchhoff’s voltage law – states that over an entire circuit, the
energy taken out must equal the energy supplied by the
battery.
M
L
Glossary
joule – a unit for measuring work; a joule is equal to one
newton of force times one meter of distance; the
abbreviation is J.
products of a reaction is equal to the total mass of reactants.
machine – a type of mechanical system.
magenta – a pink-purple color that is created when green is
absorbed and red and blue are reflected.
latent heat – heat that cannot be sensed with a thermometer;
the heat released when vapor condenses into a liquid.
magnetic field – an area of magnetic force that surrounds
magnetic objects.
latitude – angular distance north and south from the Earth’s
equator measured through 90 degrees.
magnetic force – a force exerted on a particle or object
traveling in a magnetic field.
law of conservation of mass – states that the total mass of
magnetic north pole – the end of a magnetic object that points
toward the geographic north pole of the Earth.
517
magnetic south pole – the end of a magnetic object that points
away from the geographic north pole of the Earth.
malleability – a solid’s ability to be pounded into thin sheets.
mass – a measure of the inertia of an object; the amount of
matter an object has.
mass number – the total number of protons and neutrons in the
nucleus of an atom.
matter – anything that has mass and takes up space.
measurement– the act or process of measuring in multiples of
a specific unit.
mechanical advantage – the ratio of output force to input force.
mechanical system – a series of interrelated, moving parts that
work together to accomplish a specific task.
metabolic rate – the rate of energy consumption at all times
(resting or awake) within the body.
metric system – a system of measuring that uses, for example,
distance units of millimeters, centimeters, meters, and
kilometers.
mixture – substance that contains more than one kind of
matter.
mole – one set of 6.02 x 1023 atoms or molecules.
molecular formula – includes the symbols for and number of
atoms of each element in a compound.
molecule – the smallest particle of a compound that retains the
properties of the compound.
518
momentum – the mass of an object multiplied by its speed or
velocity.
monoatomic ions – ions that contain only one type of atom.
musical scale – frequencies of sound that fit into a special
pattern.
N
nanometer – a unit of measurement that is equal to one
billionth of a meter.
natural (or buoyant) convection – a process that is influenced
by gravitational forces and by which hot, less-dense air
displaces cooler, denser air.
natural frequency – describes how an object vibrates; for
example, a guitar string strummed repeatedly has its own
natural force.
natural world– the aspects of the world not created or
constructed by people.
negative charge – one of two types of electric charge; the other
type is positive charge.
net force – the amount of force that overcomes an opposing
force to cause motion; the net force can be zero if the
opposing forces are equal.
neutral – (1) a solution that has a pH of 7, meaning it has equal
numbers of H+ and OH-, or acidic and basic, ions; (2) when
one proton is paired with one electron.
neutron – an uncharged particle found in the nucleus of an
atom.
newton – a unit of force; the abbreviation is N.
Newton’s first law of motion – states any object at rest will
remain at rest unless acted on by an unbalanced force; an
object in motion continues with constant speed and
direction in a straight line unless acted on by an unbalanced
force.
open circuit – a circuit in which there is a break in the wire so
that current cannot flow; a switch turned to the “off”
position is one way to cause a break in the wire.
Newton’s third law of motion – states that whenever one
object exerts a force on another, the second object exerts an
equal and opposite force on the first.
optics – the study of how light behaves.
nonpolar – a term used to describe a molecule or covalent bond
that does not have partial charges; oils and fats are nonpolar
molecules.
normal – a line that is perpendicular to the surface of an object.
nuclear energy – the form of energy that comes from splitting
the nucleus of an atom, or fusing two nuclei of an atom.
nuclear reaction – a reaction that involves splitting the nucleus
of an atom or fusing two nuclei; these reactions produce
much more energy than chemical reactions.
nucleons – the protons and neutrons in the nucleus of an atom.
nucleus – the center core of an atom that contains protons and
neutrons.
O
octet – an atom’s eight valence electrons.
octet rule – states that atoms form bonds with other atoms by
sharing or transferring them to complete their octet and
become stable.
ohm – the unit of measurement for electrical resistance; the
abbreviation is Ω.
Ohm’s law – describes the mathematical relationship present in
most circuits.
oscillator – a system that shows harmonic motion.
output – what the machine does.
output arm – of the lever on a fulcrum, the output arm is the
side where the output force is applied.
Glossary
Newton’s second law of motion – states that the acceleration
of an object is directly proportional to the force acting on it
and inversely proportional to its mass.
output force – the force a machine applies to accomplish a
task.
oxidation number – indicates how many electrons are lost or
gained (or shared) when bonding occurs.
P
parallel – lying or moving in the same direction, but always the
same distance apart (i.e., never intersecting).
parallel circuit – a circuit in which the current can take more
than one path.
pascal (Pa) – the SI unit of pressure. One pascal is equal to one
newton of force acting on one square meter of surface.
percent yield – the actual yield of product in a chemical
reaction divided by the predicted yield, and multiplied by
one hundred to get a percentage.
period – the time for one cycle.
periodic motion – cycles of motion that repeat over and over
again; the same as harmonic motion.
periodic table of elements – a table that visually organizes the
similarities between all known elements.
519
permanent magnet – a magnetic object that retains its
magnetic properties without external influence.
perpendicular – forming a 90 degree angle with a given edge
or surface.
polar – something that has two poles; a term used to describe
a molecule or covalent bond that has partial charges; water
is a polar molecule.
pH – the exact concentrations of H+ ions and OH- ions in a
solution.
polarization – a way of describing the direction (such as
vertical or horizontal) that waves of light travel.
pH indicator – a solution or object that changes color to
identify the pH of a solution.
polarizer – a partially transparent material that lets through
only one polarization of light.
pH scale – a scale that runs from 0 (strongly acidic) to 14
(strongly basic, or alkaline).
polyatomic ions – ions that contain more than one type of
atom.
phase – refers to where an oscillator is in its cycle.
polymer – a large molecule that is composed of repeating
smaller molecules called subunits or monomers.
photoluminescence – occurs when light energy makes
something else give off light.
photoreceptors – rod and cone cells in the retina of the eye
that receive light and release a chemical signal that travels
down the optic nerve to the brain.
photosynthesis – a chemical reaction performed by plants in
which energy from the sun is converted to chemical energy;
carbon dioxide is converted to sugar in this reaction.
polymerization – the production of a very large molecule by a
series of synthesis reactions.
position – a point in space of an object compared to where it
started.
positive charge – one of two types of electric charge; the other
type is negative charge.
potential energy – stored energy that comes from position.
physical change – change in the physical properties of a
substance.
potentiometer – a variable resistor.
physical models – models that are made of materials and that
can be touched and measured; engineers construct scale
physical models to test a structure before building it.
power – the rate at which work is done.
pitch – property of a sound determined by the frequency of the
waves producing it.
pixel – a dot on your computer screen whose color can change
depending on the three numbers your computer assigns to
it.
520
plane waves – waves that move in straight lines.
pounds – English system unit of force.
power stroke – in a four-stroke engine, the stroke in which the
ignited fuel expands and pushes the piston back.
precipitate – substance formed when one of the compounds in
a double-displacement reaction is insoluble, or does not
dissolve in water.
pressure – a measure of the force felt by the walls of a
container.
radioactive isotope – an unstable isotope of an element that
spontaneously undergoes radioactive decay.
ray diagram – a diagram which illustrates how several light
rays behave as they go through an optical system.
pressure – the force acting on a unit area of surface.
react – describes how atoms interact when forming a chemical
bond with another atom.
procedure – a collection of all the techniques you use to do an
experiment.
reactants – a substance that enters into and is altered in the
course of a chemical reaction.
products – substances that are produced in a chemical reaction
from reactants.
real image – an image formed by rays of light coming together
on a surface like a screen or the retina of the eye.
protein – a nitrogen-containing molecule found in foods that is
used to build structural parts of cells and to facilitate
cellular reactions.
recoil – backward acceleration from the reaction force.
proton – a subatomic particle identical with the nucleus of the
hydrogen atom; found with neutrons in all atomic nuclei;
carries a positive charge.
prototype – a working model of a design that can be tested to
see if it works.
R
radiant energy – another term for electromagnetic energy.
radiation – (1) the process of emitting radiant energy; (2) a
term to describe the particles and energy that are emitted
from radioactive substances.
Glossary
precipitation – water vapor in the atmosphere falling back to
Earth in the form of rain, hail, sleet, or snow; one phase in
the water cycle.
reflected ray – the ray that bounces off an object.
reflection – the bounce of a wave off a surface.
reflectors – objects that reflect light.
refraction – occurs when light passes from one transparent
material into another and bends.
relative humidity – the amount of water vapor in the air.
relative mass – a quantity that allows for comparison between
amounts of matter that are very small.
research question – a question that is solved through
investigation.
resistance – the measure of an object’s ability to conduct
current.
radiation – a type of heat transfer that occurs by
electromagnetic waves.
resistors – components that are used to control current in many
circuits.
radioactive – a term to describe an atomic state when the
nucleus is emitting radiation in the form of particles and
energy until it becomes more stable.
resonance – an occurrence whereby the natural frequency of a
system is exactly in tune with a force applied to the system.
reverberation – multiple echoes of sound.
521
rod cells – photoreceptor cells in the retina of the eye that
respond to differences in brightness.
solar power – radiant energy from the sun that is harnessed for
use.
rolling friction – resistance created when one object rolls over
another one.
solubility – refers to the amount of solute that can be dissolved
in a certain volume of solvent under certain conditions.
S
solubility rules – a set of rules that identifies whether a
combination of ions will dissolve or form a precipitate in
water.
saturated – the state of a mixture in which the maximum
amount of solute has dissolved in a solution.
scientific evidence – any observation that can be repeated with
the same results.
scientific method – a process that is used to gather evidence
that leads to understanding.
solute – the substance in a solution in the smallest amount; the
solute is dissolved by the solvent.
scientific model – a method of representing the relationship
between variables.
solution – a mixture of two or more substances that is
homogenous at the molecular level; a solution consists of a
solute and a solvent.
sea breeze – air current created when hot air rises over land
due to convection and is replaced by cooler air.
solvent – the component of a solution that dissolves the solute
and is present in the greatest amount.
second – a commonly used unit of time; 1/60 of a minute.
sonogram– special kind of graph that shows how loud sound
is at different frequencies.
semiconductor – material between conductor and insulator in
its ability to carry current.
series circuit – a circuit in which the current only has one path.
spectral diagram – a diagram that shows the wavelengths and
intensities of light emitted from a light source.
short circuit – a branch in a circuit with zero or very low
resistance.
speed – describes movement from one place to another over
time; distance divided by time.
simple machine – an unpowered mechanical device, such as a
lever, which has an input and an output force.
stable – (1) a term used to describe an atom that has a balance
of charge; (2) a non-radioactive nucleus.
single-displacement reaction – a reaction in which one element
replaces a similar element in a compound.
standing wave – a wave trapped in one spot.
sliding friction – resistance created when two surfaces rub
against one another.
522
solubility value – a number that describes a solute-solvent
system; it includes the mass of solute, amount of solvent,
and temperature.
static electricity – a buildup of either positive or negative
charge; consists of isolated motionless charges, like those
produced by friction.
strong nuclear force – the force that holds protons together
when they are very close together (only 10-15 meters apart).
subscript – a number in a chemical formula that show the
number of a type of atom.
substance – a mixture that cannot be separated into different
kinds of matter using physical means.
subtractive primary colors – magenta, yellow, and cyan.
supersaturated – condition of a solution when more solute has
dissolved than is normally possible at a given temperature.
supersonic – motion that is faster than sound.
surface runoff – water that flows over land until it reaches
lakes, rivers, or other surface water areas.
surface water – water contained in places such as lakes, ponds,
rivers, streams, and reservoirs.
suspensions – a type of mixture in which the particles (atoms
or molecules) are larger than 1,000 nanometers in diameter.
system – a collection of matter and processes that occur in a
certain space and can be studied; systems can be open or
closed.
T
temperature – the measurement used to quantify the
sensations of hot and cold.
tensile strength – a measure of how much pulling, or tension,
a material can withstand before breaking.
terahertz – a unit of measurement that is equal to
1,000,000,000 cycles per second.
thermal conductor – a material that easily conducts heat.
thermal energy – energy that comes from heat and the
vibration of atoms and molecules.
thermal equilibrium – a state that results when heat flows from
a hot object to a cold object until they are at the same
temperature.
thermal insulators – materials that are poor conductors of heat.
Glossary
subatomic particles – particles that are smaller than an atom;
protons, neutrons, and electrons are subatomic particles.
thermal conductivity – the ability of material to transfer heat.
thermometer – an instrument for measuring the temperature
typically by the rise and fall of a liquid in a tube.
thermostat – a device that controls another device based on
changes in temperature.
time – a useful measurement of changes in motion or events;
all or part of the past, present, and future.
total internal reflection – occurs when light within a material
approaches the surface at greater than the critical angle and
reflects back.
transpiration – process in which plants open tiny pores on their
leaves to gain carbon dioxide but lose water; one phase in
the water cycle.
transverse wave – a wave whose oscillation is perpendicular to
the direction the wave travels.
trial – each time an experiment is tried.
trough – the low point on a wave.
turbine – an engine whose central driveshaft is fitted with
curved vanes spun by the pressure of water, steam, or gas.
Tyndall effect – a way of visually distinguishing colloids from
true solutions.
523
U
ultraviolet light – light of a wavelength shorter than those of
visible light but longer than those of X-rays.
water cycle – see hydrologic cycle.
unsaturated – a solution in which it is possible for more solute
to be dissolved.
wavefronts – another term used to describe the crests of a
wave.
V
valence electrons – the electrons in an atom that are involved
in the formation of chemical bonds.
watt – the metric, or SI, unit of power.
wavelength – the distance from peak to peak, crest to crest, or
trough to trough of a wave.
weight – a force created by gravity.
variables – factors that affect the results of an experiment.
white noise – an equal mixture of all frequencies, like white is
a mixture of all colors.
velocity – describes movement from one place to another over
time and in a certain direction.
work – the quantity of force times distance; the result of
machines performing tasks.
versorium – the earliest version of today’s electroscope.
virtual image – an image formed when rays of light appear to
be coming from a place other than where the actual object
exists; a virtual image cannot be projected on a screen.
viscosity – a measure of a material’s resistance to flow.
viscous friction – resistance created by objects moving in water
or other fluids.
visible light – the light you can see in the range between 400
and 700 nanometers.
volt – the measurement unit for voltage.
voltage – the amount of potential energy that each unit of
electrical charge has.
524
W
Y
yellow – a color that is created when blue is absorbed and red
and green are reflected.
A
efficiency of . . . . . . . . . . . . . . . . . . . . 85
parts of . . . . . . . . . . . . . . . . . . . . . . . . . 67
binary compounds
definition of . . . . . . . . . . . . . . . . . . . 340
naming . . . . . . . . . . . . . . . . . . . . . . . . 339
Black, Joseph . . . . . . . . . . . . . . . . . . . . . 460
blood, pH of . . . . . . . . . . . . . . . . . . . . . . . 443
Bohr, Niels . . . . . . . . . . . . . . . . . . . . . . . . 314
Boyle, Robert . . . . . . . . . . . . . . . . . . . . . 300
Brand, Hennig . . . . . . . . . . . . . . . . . . . . 320
British thermal unit (Btu) . . . . . . . . . . 456
brittleness . . . . . . . . . . . . . . . . . . . . . . . . . 293
buoyancy
definition of . . . . . . . . . . . . . . . . . . . 297
of liquids . . . . . . . . . . . . . . . . . . . . . . 297
buoyant convection . . . . . . . . . . . . . . . 471
B
calories . . . . . . . . . . . . . . . . . . . .456, 458, 487
Campagnolo, Tullio . . . . . . . . . . . . . . . . 85
carbohydrates . . . . . . . . . . . . . . . . . . . . . 488
carbon dating . . . . . . . . . . . . . . . . . . . . . . 393
carbon dioxide . . . . . . . . . . . . . . . . 395, 396
carbon reactions
blood chemistry . . . . . . . . . . . . . . . 443
carbon dioxide . . . . . . . . . . . . 395, 396
definition of . . . . . . . . . . . . . . . . . . . 394
Earth’s atmosphere . . . . . . . . . . . . 395
emissions . . . . . . . . . . . . . . . . . . . . . . 396
fossil fuels . . . . . . . . . . . . . . . . . . . . . 395
global warming . . . . . . . . . . . . . . . . 396
photosynthesis . . . . . . . . . . . . . . . . . 394
balancing chemical equations . 359, 366
bases
chemistry of . . . . . . . . . . . . . . . . . . . 440
definition of . . . . . . . . . . . . . . . . . . . 437
digestion . . . . . . . . . . . . . . . . . . 437, 440
sodium hydroxide . . . . . . . . . . . . . 438
batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
beats in music . . . . . . . . . . . . . . . . . . . . . 225
Benedictus, Edouard . . . . . . . . . . . . . . 293
beta decay . . . . . . . . . . . . . . . . . . . . . . . . . 390
beta particles . . . . . . . . . . . . . . . . . . . . . . 390
bicycles
Index
absorption
absorbers . . . . . . . . . . . . . . . . . . . . . . 476
as a wave action . . . . . . . . . . . . . . . 202
of energy . . . . . . . . . . . . . . . . . . . . . . 318
of light . . . . . . . . . . . . . . . . . . . . 245, 247
reflectors . . . . . . . . . . . . . . . . . . . . . . 476
acceleration . . . . . . . . . . . . . . . . . .33, 36, 49
effects of friction on . . . . . . . . . . . . 57
measuring . . . . . . . . . . . . . . . . . . . . . . 35
of gravity . . . . . . . . . . . . . . . . . . . . . . . 36
speed vs. time graph . . . . . . . . . . . . 37
acid precipitation . . . . . . . . . . . . . . . . . . 444
acid rain . . . . . . . . . . . . . . . . . . . . . . . . . . . 444
acids
chemistry of . . . . . . . . . . . . . . . . . . . 440
definition of . . . . . . . . . . . . . . . . . . . 437
digestion . . . . . . . . . . . . . . . . . . 437, 440
examples of . . . . . . . . . . . . . . . . . . . 442
hydrochloric acid . . . . . . . . . . . . . . 438
uses . . . . . . . . . . . . . . . . . . . . . . . . . . . 440
acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . 218
adenosine triphosphate (ATP) . . . . . 489
air friction . . . . . . . . . . . . . . . . . . . . . . . . . . 56
alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404
alpha decay . . . . . . . . . . . . . . . . . . . . . . . 390
alpha particles . . . . . . . . . . . . . . . . . . . . . 390
ampere . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Ampere, Andre-Marie . . . . . . . . . . . . . 119
amplitude
definition of . . . . . . . . . . . . . . . . . . . 183
determining from a graph . . . . . . 185
of a wave . . . . . . . . . . . . . . . . . . 185, 198
relationship to resonance . . . . . . 204
Archimedes . . . . . . . . . . . . . . . . . . . . . . . 297
Archimedes’ principle . . . . . . . . . . . . . 297
atmosphere, chemistry of . . . . . . . . . . 395
atomic mass . . . . . . . . . . . . . . . . . . . . . . . 322
atomic mass unit (amu) . . . . . . . . 322, 341
atomic number . . . . . . . . . . . . . . . . 315, 322
atomic theory . . . . . . . . . . . . . . . . . . . . . 312
atoms
arrangement of electrons in . . . . 318
composition of . . . . . . . . . . . . . . . . 311
definition of . . . . . . . . . . . . . . . . . . . 283
history of atomic theory . . . . . . . 312
isotopes . . . . . . . . . . . . . . . . . . . . . . . 315
model of . . . . . . . . . . . . . . . . . . . . . . . 313
average speed . . . . . . . . . . . . . . . . . . . . . . 32
Avogadro, Count Amedeo . . . . . . . . . 343
Avogadro’s number . . . . . . . . . . . . . . . 343
C
525
cause and effect . . . . . . . . . . . . . . . . . . . . 28
Celsius scale . . . . . . . . . . . . . . . . . . . . . . 452
Celsius, Anders . . . . . . . . . . . . . . . . . . . 452
Chadwick, James . . . . . . . . . . . . . . . . . . 314
charge
electric . . . . . . . . . . . . . . . . . . . . . . . . 105
measuring with an electroscope 108
Charles, Jacques . . . . . . . . . . . . . . . . . . 299
chemical bonds
covalent bonds . . . . . . . . . . . . . . . . 331
energy levels . . . . . . . . . . . . . . . . . . 327
octet rule . . . . . . . . . . . . . . . . . . . . . . 327
stable atoms . . . . . . . . . . . . . . . . . . . 327
types of . . . . . . . . . . . . . . . . . . . . . . . 330
unstable atoms . . . . . . . . . . . . . . . . 327
valence electrons . . . . . . . . . . . . . . 330
chemical changes
compared to physical changes . 354
reactions . . . . . . . . . . . . . . . . . . 375–379
chemical energy . . . . . . . . . . . . . . . . . . . . 94
chemical equations
balancing . . . . . . . . . . . . . . . . . . 359, 366
conservation of atoms . . . . . 358, 367
determining ratios . . . . . . . . . . . . . 366
writing . . . . . . . . . . . . . . . . . . . . 361–362
chemical formulas
covalent compounds . . . . . . . . . . . 340
definition of . . . . . . . . . . . . . . . . . . . 334
empirical . . . . . . . . . . . . . . . . . . . . . . 340
formula mass . . . . . . . . . . . . . . . . . . 342
ionic bonds . . . . . . . . . . . . . . . . . . . . 334
oxidation numbers . . . . . . . . . . . . 334
writing . . . . . . . . . . . . . . . . . . . . 336, 358
chemical potential energy . . . . . . . . . . 91
526
chemical reactions
addition reaction . . . . . . . . . . . . . . 375
combustion reactions . . . . . . . . . . 378
compared to nuclear reactions . 388
decomposition reactions . . . . . . . 376
definition of . . . . . . . . . . . . . . . . . . . 235
double-displacement reactions 377
endothermic reactions . . . . . . . . . 382
exothermic reactions . . . . . . . . . . 381
light from . . . . . . . . . . . . . . . . . . . . . 235
precipitate . . . . . . . . . . . . . . . . . . . . . 377
predicting the products of . . . . . 380
single-displacement reactions . 377
writing . . . . . . . . . . . . . . . . . . . . 358, 359
chemical symbols . . . . . . . . . . . . . . . . . 322
chemistry of Earth’s atmosphere . . 395
circuit breakers . . . . . . . . . . . . . . . . . . . . 119
circuit diagrams . . . . . . . . . . . . . . . . . . . 103
circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
see electricity
circular motion . . . . . . . . . . . . . . . . . . . . 186
circular waves . . . . . . . . . . . . . . . . . . . . . 200
closed circuits . . . . . . . . . . . . . . . . . . . . . 104
cloud seeding . . . . . . . . . . . . . . . . . . . . . 428
CMYK color process . . . . . . . . . . . . . . 248
colloids
definition of . . . . . . . . . . . . . . . . . . . 405
distinguishing from solutions . . 405
properties of . . . . . . . . . . . . . . . . . . . 405
Tyndall effect . . . . . . . . . . . . . . . . . 405
color
description of . . . . . . . . . . . . . . . . . 242
primary . . . . . . . . . . . . . . . . . . . 243, 244
seeing . . . . . . . . . . . . . . . . . . . . . . . . . 243
color blindness . . . . . . . . . . . . . . . . . . . . 244
combustion reactions . . . . . . . . . . . . . . 378
compasses . . . . . . . . . . . . . . . . . . . . . . . . 162
compounds
covalent . . . . . . . . . . . . . . . . . . . . . . . 331
definition of . . . . . . . . . . . . . . . . . . . 278
ionic . . . . . . . . . . . . . . . . . . . . . . . . . . 334
conceptual models . . . . . . . . . . . . . . . . . 25
condensation . . . . . . . . . . . . . . . . . . . . . . 427
conduction . . . . . . . . . . . . . . . . . . . . . . . . 467
conductors
definition of . . . . . . . . . . . . . . . . . . . 121
effect of temperature on . . . . . . . 134
insulators . . . . . . . . . . . . . . . . . . . . . . 121
thermal . . . . . . . . . . . . . . . . 467, 468, 469
conservation of energy, law of . . . . . 90
conservation of mass, law of . . . . . . 363
conservation of momentum, law of . 60
constructive interference . . . . . . . . . . 206
convection
definition of . . . . . . . . . . . . . . . . . . . 470
forced convection . . . . . . . . . . . . . 473
natural or buoyant . . . . . . . . . . . . . 471
converging lens . . . . . . . . . . . . . . . 255, 261
Copernicus, Nicholas . . . . . . . . . . . . . . 25
Cori, Gerty Theresa . . . . . . . . . . . . . . . 489
coulomb . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Coulomb, Charles-Augustin de . . . . 107
covalent bonds
compared to ionic bonds . . . . . . 332
definition of . . . . . . . . . . . . . . . . . . . 331
covalent compounds . . . . . . . . . . . . . . 340
crests of waves . . . . . . . . . . . . . . . . . . . . 200
Crooks, William . . . . . . . . . . . . . . . . . . 313
D
da Vinci, Leonardo . . . . . . . . . . . . . . . . . 73
Dalton, John . . . . . . . . . . . . . . . . . . . 312, 320
decomposition reactions . . . . . . . . . . . 376
density
definition of . . . . . . . . . . . . . . . . . . . 291
liquids compared to solids . . . . . 296
of fluids . . . . . . . . . . . . . . . . . . . . . . . 295
of solids . . . . . . . . . . . . . . . . . . . . . . . 291
destructive interference . . . . . . . . . . . . 206
dew point . . . . . . . . . . . . . . . . . . . . . . . . . 485
diffraction
action of sound wave . . . . . . . . . . 213
as a wave action . . . . . . . . . . . . . . . 202
digestion . . . . . . . . . . . . . . . . . . . . . . 437, 440
dissolving rate
definition of . . . . . . . . . . . . . . . . . . . 406
surface area . . . . . . . . . . . . . . . . . . . 407
timed-release medications . . . . . 408
distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
diverging lens . . . . . . . . . . . . . . . . . 255, 261
dot diagrams . . . . . . . . . . . . . . . . . . . . . . 330
double-displacement reactions . . . . 377
Dulong, Pierre Louis . . . . . . . . . . . . . . 460
E
ear
hearing . . . . . . . . . . . . . . . . . . . . . . . . 213
parts of . . . . . . . . . . . . . . . . . . . . . . . . 213
Earth
as a water planet . . . . . . . . . . . . . . . 425
chemistry of atmosphere . . . . . . . 395
distribution of water . . . . . . . . . . . 429
harmonic motion in . . . . . . . . . . . . 180
seasons of . . . . . . . . . . . . . . . . . . . . . 483
temperature of . . . . . . . . . . . . . 483, 484
Edison, Thomas A. . . . . . . . . . . . . 105, 475
efficiency
of bicycles . . . . . . . . . . . . . . . . . . . . . . 85
of machines . . . . . . . . . . . . . . . . . . . . 85
elasticity . . . . . . . . . . . . . . . . . . . . . . . . . . 292
electric cars . . . . . . . . . . . . . . . . . . . . . . . 138
electric charge
coulomb . . . . . . . . . . . . . . . . . . . . . . . 107
current . . . . . . . . . . . . . . . . . . . . . . . . 117
definition of . . . . . . . . . . . . . . . . . . . 105
lightning . . . . . . . . . . . . . . . . . . . . . . 107
negative . . . . . . . . . . . . . . . . . . . . . . . 105
positive . . . . . . . . . . . . . . . . . . . . . . . . 105
electric motors . . . . . . . . . . . . . . . . . . . . 168
electrical energy . . . . . . . . . . . . . . . . 94, 171
electricity . . . . . . . . . . . . . . . . . . . . . . . . . 105
amps . . . . . . . . . . . . . . . . . . . . . . . . . . 119
as charged by utility companies 139
circuit diagrams . . . . . . . . . . . . . . . 103
circuits . . . . . . . . . . . . . . . . . . . . . . . . 101
circuits, definition of . . . . . . . . . . 102
closed circuits . . . . . . . . . . . . . . . . . 104
electrical symbols . . . . . . . . . . . . . 103
Franklin, Benjamin . . . . . . . . . . . . 105
fuses and circuit breakers . . . . . . 119
generating . . . . . . . . . . . . . . . . . . . . . 172
ground fault circuit interrupter
(GFCI) . . . . . . . . . . . . . . . . . . . . . 120
light bulbs . . . . . . . . . . . . . . . . . . . . . 125
lights . . . . . . . . . . . . . . . . . . . . . . . . . . 236
measuring . . . . . . . . . . . . . . . . . . . . . 137
open circuits . . . . . . . . . . . . . . . . . . . 104
parallel circuits . . . . . . . . . . . . 150–152
potentiometer . . . . . . . . . . . . . . . . . . 136
power . . . . . . . . . . . . . . . . . . . . . . . . . 137
series circuits . . . . . . . . . . . . . . 147–149
short circuits . . . . . . . . . . . . . . . . . . 152
static . . . . . . . . . . . . . . . . . . . . . . . . . . 106
electrolytes . . . . . . . . . . . . . . . . . . . . . . . . 441
electromagnetic force . . . . . . . . . 171, 317
electromagnetic induction . . . . . 171, 172
electromagnetic radiation . . . . . . 319, 474
electromagnetic spectrum . . . . . . . . . 237
electromagnets . . . . . . . . . . . . . . . . 169, 170
electronegativity . . . . . . . . . . . . . . . . . . 332
Index
Curie, Marie . . . . . . . . . . . . . . . . . . . . . . . 393
Curie, Pierre . . . . . . . . . . . . . . . . . . . . . . . 393
current
alternating . . . . . . . . . . . . . . . . . . . . . 120
conductor . . . . . . . . . . . . . . . . . . . . . . 121
definition of . . . . . . . . . . . . . . . . . . . 117
direct . . . . . . . . . . . . . . . . . . . . . . . . . . 120
insulator . . . . . . . . . . . . . . . . . . . . . . . 121
resistance . . . . . . . . . . . . . . . . . . . . . . 123
semiconductor . . . . . . . . . . . . . . . . . 121
superconductor . . . . . . . . . . . . . . . . 134
cyan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
cycles in harmonic motion . . . . . . . . 179
527
electrons
arrangement in atoms . . . . . . . . . 318
definition of . . . . . . . . . . . . . . . . . . . 311
energy levels of . . . . . . . . . . . . . . . 318
relationship to fireworks . . . . . . 319
electroscope . . . . . . . . . . . . . . . . . . . . . . . 108
elements . . . . . . . . . . . . . . . . . . . . . . . . . . 278
emissions . . . . . . . . . . . . . . . . . . . . . . . . . 396
endothermic reactions . . . . . . . . . . . . . 382
energy
calorie . . . . . . . . . . . . . . . . . . . . . . . . . 488
calories . . . . . . . . . . . . . . . . . . . . 456, 487
chemical . . . . . . . . . . . . . . . . . . . . . . . 94
definition of . . . . . . . . . . . . . . . . . . . . 87
electrical . . . . . . . . . . . . . . . . . . . 94, 171
food, as a source of . . . . . . . . . . . . 487
forms of . . . . . . . . . . . . . . . . . . . . . . . . 91
kinetic . . . . . . . . . . . . . . . . . . . . . . . 89, 91
mechanical . . . . . . . . . . . . . . . . . 93, 171
nuclear . . . . . . . . . . . . . . . . . . . . . . . . . 94
paying for it . . . . . . . . . . . . . . . . . . . 137
potential . . . . . . . . . . . . . . . . . . . . . 88, 91
radiant . . . . . . . . . . . . . . . . . . . . . . . . . 93
solar . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
specific heat . . . . . . . . . . . . . . . . . . . 488
transformations . . . . . . . . . . . . . . . . . 91
energy levels . . . . . . . . . . . . . . . . . . . . . . 318
energy loss . . . . . . . . . . . . . . . . . . . . . . . . 469
engineering . . . . . . . . . . . . . . . . . . . . . . . . 73
da Vinci, Leonardo . . . . . . . . . . . . . 73
definition of . . . . . . . . . . . . . . . . . . . . 73
engineering cycle . . . . . . . . . . . . . . 74
mechanical engineers . . . . . . . . . . . 69
see also technology
528
engines
external combustion engines . . 493
internal combustion . . . . . . . . . . . 495
English system . . . . . . . . . . . . . . . . . . . . . . 5
equilibrium
definition of . . . . . . . . . . . . . . . . . . . . 51
solubility . . . . . . . . . . . . . . . . . . . . . . 414
evaporation . . . . . . . . . . . . . . . . . . . . . . . 427
exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . 489
exothermic reactions . . . . . . . . . . . . . . 381
experimental techniques . . . . . . . . . . . 12
experiments
definition of . . . . . . . . . . . . . . . . . . . . . 7
experimental techniques . . . . . . . . 12
external combustion engines . . . . . . 493
eye
how it forms an image . . . . . . . . . 265
nerves . . . . . . . . . . . . . . . . . . . . . . . . . 264
optical illusions . . . . . . . . . . . . . . . 266
optical system . . . . . . . . . . . . . . . . . 264
photoreceptor cells . . . . . . . . . . . . 243
physical structure of . . . . . . . . . . . 264
F
Fahrenheit scale . . . . . . . . . . . . . . . . . . .
Fahrenheit, Gabriel . . . . . . . . . . . . . . . .
Faraday, Michael . . . . . . . . . . . . . . . . .
fats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fermi, Enrico . . . . . . . . . . . . . . . . . . . . .
fiber optics
internal reflection . . . . . . . . . . . . .
theory of . . . . . . . . . . . . . . . . . . . . . .
452
452
105
488
312
268
267
fireworks . . . . . . . . . . . . . . . . . . . . . . . . . . 319
first law of thermodynamics . . . . . . . 458
fission . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
fixed resistors . . . . . . . . . . . . . . . . . . . . . 135
fluids
buoyancy of . . . . . . . . . . . . . . . . . . . 297
density of . . . . . . . . . . . . . . . . . . . . . 295
viscosity of . . . . . . . . . . . . . . . . . . . . 302
fluorescent light bulbs . . . . . . . . . . . . . 236
food
as a source of energy . . . . . . . . . . 487
calories in . . . . . . . . . . . . . . . . . . . . . 487
carbohydrates . . . . . . . . . . . . . . . . . 488
fats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488
protein . . . . . . . . . . . . . . . . . . . . . . . . 488
force
definition of . . . . . . . . . . . . . . . . . . . . 69
input and output . . . . . . . . . . . . . 67, 69
net . . . . . . . . . . . . . . . . . . . . . . . . . . 51, 57
related to acceleration . . . . . . . . . . 49
simple machines . . . . . . . . . . . . 68, 69
units of . . . . . . . . . . . . . . . . . . . . . . . . . 46
forced convection . . . . . . . . . . . . . . . . . 473
formula mass
calculating . . . . . . . . . . . . . . . . 344, 346
definition of . . . . . . . . . . . . . . . . . . . 342
formulas
acceleration . . . . . . . . . . . . . . . . . . . . 50
density . . . . . . . . . . . . . . . . . . . . . . . . 291
electric power . . . . . . . . . . . . . . . . . 138
force . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
frequency . . . . . . . . . . . . . . . . . . . . . 182
heat . . . . . . . . . . . . . . . . . . . . . . . . . . . 457
kinetic energy . . . . . . . . . . . . . . . . . . 89
G
Galileo . . . . . . . . . . . . . . . . . . . . . . . . . . 25, 34
gamma rays . . . . . . . . . . . . . . . . . . . 238, 390
gases, solubility of . . . . . . . . . . . . . . . . 413
gears and rotating machines . . . . . . . . 75
Geiger, Hans . . . . . . . . . . . . . . . . . . . . . . 313
generators . . . . . . . . . . . . . . . . . . . . . 168, 172
Gilbert, William . . . . . . . . . . . . . . . . . . . 108
global warming . . . . . . . . . . . . . . . 396, 482
graphical models . . . . . . . . . . . . . . . . . . . 26
graphs
harmonic motion . . . . . . . . . . 184, 185
making predictions . . . . . . . . . . . . . 27
position vs. time . . . . . . . . . . . . . . . . 30
speed vs. time . . . . . . . . . . . . . . . . . . 38
temperature-solubility . . . . . . . . . 412
gravity . . . . . . . . . . . . . . . . . . . . . . . . . . 36, 52
ground fault circuit interrupter (GFCI)
120
groundwater . . . . . . . . . . . . . . . . . . . . . . . 426
H
half-life . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
hardness . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
harmonic motion . . . . . . . . . . . . . . . . . . 179
amplitude . . . . . . . . . . . . . . . . . . . . . 183
compared to circular motion . . . 186
cycles . . . . . . . . . . . . . . . . . . . . . . . . . 179
definition of . . . . . . . . . . . . . . . . . . . 179
examples of . . . . . . . . . . . . . . . . . . . 180
graphs . . . . . . . . . . . . . . . . . . . . . . . . . 184
in art and music . . . . . . . . . . . . . . . 181
in technology . . . . . . . . . . . . . . . . . . 181
measuring . . . . . . . . . . . . . . . . . . . . . 182
oscillators . . . . . . . . . . . . . . . . . . . . . 180
systems . . . . . . . . . . . . . . . . . . . . . . . . 180
harmonics . . . . . . . . . . . . . . . . . . . . . . . . . 205
harmony . . . . . . . . . . . . . . . . . . . . . . . . . . 225
heat
calculating . . . . . . . . . . . . . . . . . . . . 457
calories . . . . . . . . . . . . . . . . . . . . . . . . 456
convection . . . . . . . . . . . . . . . . . . . . 470
definition of . . . . . . . . . . . . . . . . . . . . 93
flow of . . . . . . . . . . . . . . . . . . . . . . . . 458
mechanical systems . . . . . . . . . . . 491
specific heat . . . . . . . . . . . . . . . 457, 458
thermal conductivity . . . . . . . . . . . 467
thermal conductors . . . . . . . . . . . . 468
thermal energy . . . . . . . . . . . . . . . . . 93
thermal insulators . . . . . . . . . . . . . 468
see also latent heat and specific heat
heat transfer . . . . . . . . . . . . . . . . . . . . . . . 467
heat-temperature rule. . . . . . . . . . . . . . 456
hertz . . . . . . . . . . . . . . . . . . . . . . . . . . 182, 198
heterogeneous mixtures . . . . . . . . . . . 277
homogeneous mixtures . . . . . . . . . . . . 277
humidity . . . . . . . . . . . . . . . . . . . . . . . . . . 485
hydrogen bonds . . . . . . . . . . . . . . . . . . . 410
hypothesis . . . . . . . . . . . . . . . . . . . . . . . . 9, 10
Index
mass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
mechanical advantage . . . . . . . . . . 69
momentum . . . . . . . . . . . . . . . . . . . . . 60
percent yield . . . . . . . . . . . . . . . . . . 368
period and frequency . . . . . . . . . . 182
potential energy . . . . . . . . . . . . . . . . 88
power . . . . . . . . . . . . . . . . . . . . . . . . . . 86
speed . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
speed of wave . . . . . . . . . . . . . . . . . 199
volume . . . . . . . . . . . . . . . . . . . . . . . . 280
work . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
fossil fuels . . . . . . . . . . . . . . . . . . . . . . . . 395
Franklin, Benjamin . . . . . . . . . . . . . . . . 105
free fall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
frequency
calculating . . . . . . . . . . . . . . . . . . . . . 182
definition of . . . . . . . . . . . . . . . . . . . 182
harmonic motion . . . . . . . . . . . . . . 182
of sound . . . . . . . . . . . . . . . . . . . . . . . 219
of waves . . . . . . . . . . . . . . . . . . . . . . . 198
see also natural frequency
friction
definition of . . . . . . . . . . . . . . . . . . . . 56
mechanical systems . . . . . . . . . . . 492
reducing . . . . . . . . . . . . . . . . . . . . . . . 492
types of . . . . . . . . . . . . . . . . . . . . . . . . . 56
fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
fusion . . . . . . . . . . . . . . . . . . . . . . . . . 387, 394
529
I
image
real . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
virtual . . . . . . . . . . . . . . . . . . . . . . . . . 262
incandescence . . . . . . . . . . . . . . . . . . . . . 236
index of refraction . . . . . . . . . . . . . . . . 263
inertia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
infrared radiation . . . . . . . . . . . . . . . . . . 475
infrared waves . . . . . . . . . . . . . . . . . . . . 238
input force . . . . . . . . . . . . . . . . . . . . . . 68, 69
instantaneous speed . . . . . . . . . . . . . . . . 32
insulators
electrical . . . . . . . . . . . . . . . . . . . . . . 121
thermal . . . . . . . . . . . . . . . . . . . . . . . . 468
interference
sound . . . . . . . . . . . . . . . . . . . . . . . . . 223
waves . . . . . . . . . . . . . . . . . . . . . . . . . 206
internal combustion engines . . . . . . . 495
internal reflection . . . . . . . . . . . . . . . . . 268
ionic bonds
compared to covalent bonds . . . 332
definition of . . . . . . . . . . . . . . . . . . . 330
ionic compounds . . . . . . . . . . . . . . . . . . 334
ions
monoatomic . . . . . . . . . . . . . . . . . . . 336
polyatomic . . . . . . . . . . . . . . . . . . . . 337
isotopes
definition of . . . . . . . . . . . . . . . . . . . 316
radioactive . . . . . . . . . . . . . . . . . . . . 393
530
J
joule . . . . . . . . . . . . . . . . . . . . . . . . 83, 84, 456
Joule, James Prescott . . . . . . . . . . . . . . 456
K
Kepler, Johannes . . . . . . . . . . . . . . . . . . . 25
Kevlar® . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
kinetic energy
calculating . . . . . . . . . . . . . . . . . . . . . 89
definition of . . . . . . . . . . . . . . . . . . . . 89
Kirchhoff, Gustav Robert . . . . . . . . . 149
Kirchhoff’s current law . . . . . . . . . . . 150
Kirchhoff’s voltage law . . . . . . . . . . . 149
Kwolek, Stephanie . . . . . . . . . . . . . . . . 294
L
lasers
definition of . . . . . . . . . . . . . . . . . . . 270
history of . . . . . . . . . . . . . . . . . . . . . . 270
types of . . . . . . . . . . . . . . . . . . . . . . . 270
latent heat . . . . . . . . . . . . . . . . . . . . . . . . . 460
Lavoisier, Antoine Laurent . . . . . . . . 363
law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
law of conservation of energy . 90, 149,
458
law of conservation of mass . . . . . . . 363
law of reflection . . . . . . . . . . . . . . . . . . 260
law of universal gravitation . . . . . . . . 54
laws of motion . . . . . . . . . . . . . . . . . . 45, 59
lens
converging . . . . . . . . . . . . . . . . 255, 261
diverging . . . . . . . . . . . . . . . . . . 255, 261
focal length . . . . . . . . . . . . . . . . . . . 261
focal point . . . . . . . . . . . . . . . . . . . . 261
levers
definition of . . . . . . . . . . . . . . . . . . . . 71
mechanical advantage . . . . . . . . . . 72
parts of . . . . . . . . . . . . . . . . . . . . . . . . . 71
Lewis, G.N. . . . . . . . . . . . . . . . . . . . . . . . 330
light
description of . . . . . . . . . . . . . 233, 234
electric . . . . . . . . . . . . . . . . . . . . . . . . 236
electromagnetic spectrum . . . . . 237
energy levels of atoms . . . . . . . . 235
photoluminescence . . . . . . . . . . . . 234
rays . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
sources of . . . . . . . . . . . . . . . . . . . . . 234
speed of . . . . . . . . . . . . . . . . . . . . . . . 239
waves . . . . . . . . . . . . . . . . . . . . . . . . . 237
light bulbs . . . . . . . . . . . . . . . . . . . . . . . . 125
lightning . . . . . . . . . . . . . . . . . . . . . . 107, 123
longitudinal waves . . . . . . . . . . . . . . . . 197
M
machines
definition of . . . . . . . . . . . . . . . . . . . . 68
designing . . . . . . . . . . . . . . . . . . . . . . . 76
efficiency of . . . . . . . . . . . . . . . . . . . . 85
simple . . . . . . . . . . . . . . . . . . . . . . . . . . 68
magenta . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
mechanical energy . . . . . . . . . . . . . 93, 171
mechanical systems . . . . . . . . . . . . . . . . 67
external combustion engine . . . . 493
friction . . . . . . . . . . . . . . . . . . . . . . . . 492
heat generated in . . . . . . . . . . . . . . 491
internal combustion engine . . . . 495
machines . . . . . . . . . . . . . . . . . . . . . . . 68
simple machines . . . . . . . . . . . . . . . . 68
Melville, Herman . . . . . . . . . . . . . . . . . 304
Mendeleev, Dimitri . . . . . . . . . . . . . . . 321
metabolic rates . . . . . . . . . . . . . . . . . . . . 490
metric system . . . . . . . . . . . . . . . . . . . . . . . 5
microwaves . . . . . . . . . . . . . . . . . . . . . . . 237
mixtures
definition of . . . . . . . . . . . . . . . . . . . 277
heterogeneous . . . . . . . . . . . . . . . . . 277
homogeneous . . . . . . . . . . . . . . . . . . 277
models
conceptual . . . . . . . . . . . . . . . . . . . . . . 25
definition of . . . . . . . . . . . . . . . . . . . . 24
graphical . . . . . . . . . . . . . . . . . . . . . . . 26
physical . . . . . . . . . . . . . . . . . . . . . . . . 25
mole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
molecules
changes of state . . . . . . . . . . . . . . . 284
definition of . . . . . . . . . . . . . . . . . . . 283
movement of . . . . . . . . . . . . . . . . . . 283
nonpolar . . . . . . . . . . . . . . . . . . . . . . . 422
polar . . . . . . . . . . . . . . . . . . . . . . . . . . 421
momentum
calculating . . . . . . . . . . . . . . . . . . . . . . 60
definition of . . . . . . . . . . . . . . . . . . . . 60
monoatomic ions . . . . . . . . . . . . . . . . . . 336
motion
circular . . . . . . . . . . . . . . . . . . . . . . . . 186
cycle . . . . . . . . . . . . . . . . . . . . . . . . . . 179
harmonic . . . . . . . . . . . . . . . . . . . . . . 179
periodic . . . . . . . . . . . . . . . . . . . . . . . 184
see also harmonic motion and laws
of motion
music
beats . . . . . . . . . . . . . . . . . . . . . . . . . . 225
harmony . . . . . . . . . . . . . . . . . . . . . . . 225
musical scale . . . . . . . . . . . . . . . . . . 224
pitch . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
rhythm . . . . . . . . . . . . . . . . . . . . . . . . 224
musical scale . . . . . . . . . . . . . . . . . . . . . . 224
Index
magnetic field . . . . . . . . . . . . . . . . . . . . . 163
magnetic forces . . . . . . . . . . . . . . . . . . . 160
magnets
compasses . . . . . . . . . . . . . . . . . . . . . 162
definition of . . . . . . . . . . . . . . . . . . . 159
electromagnets . . . . . . . . . . . . 169, 170
history of . . . . . . . . . . . . . . . . . . . . . . 161
permanent . . . . . . . . . . . . . . . . . 159, 170
properties of . . . . . . . . . . . . . . . . . . . 160
malleability . . . . . . . . . . . . . . . . . . . . . . . 294
Marsden, Ernest . . . . . . . . . . . . . . . . . . . 313
mass
calculating relative mass . . . . . . . 341
conservation of . . . . . . . . . . . . . . . . 363
definition of . . . . . . . . . . . . . . . . . . . . 48
measuring . . . . . . . . . . . . . . . . . . . . . 281
mass number . . . . . . . . . . . . . . . . . . . . . . 322
matter
atoms . . . . . . . . . . . . . . . . . . . . . . . . . . 283
classifying . . . . . . . . . . . . . . . . . . . . . 277
definition of . . . . . . . . . . . . . . . . . . . 277
measuring . . . . . . . . . . . . . . . . . 280, 282
mixtures . . . . . . . . . . . . . . . . . . . . . . . 277
molecules . . . . . . . . . . . . . . . . . . . . . 283
states of . . . . . . . . . . . . . . . . . . . 283, 285
substances . . . . . . . . . . . . . . . . . . . . . 278
types of . . . . . . . . . . . . . . . . . . . . . . . . 279
meal, ready to eat . . . . . . . . . . . . . . . . . 381
measurement
English system . . . . . . . . . . . . . . . . . . 5
metric system . . . . . . . . . . . . . . . . . . . 5
mechanical advantage
calculating . . . . . . . . . . . . . . . . . . . . . . 69
levers . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
N
National Aeronautics and Space
Administration (NASA) . . . . . . . 107
natural convection . . . . . . . . . . . . . . . . . 471
natural frequency
definition of . . . . . . . . . . . . . . . . . . . 203
examples of . . . . . . . . . . . . . . . . . . . 203
resonance . . . . . . . . . . . . . . . . . . . . . 204
negative charge . . . . . . . . . . . . . . . . . . . 105
net force . . . . . . . . . . . . . . . . . . . . . . . . 51, 57
neutrons . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Newton, Sir Isaac
biographical information . . . . . . . 45
law of universal gravitation . . . . . 25
laws of motion . . . . . . . . . . .25, 45, 59
newtons, measuring in . . . . . . . . . . . . . 46
nuclear energy . . . . . . . . . . . . . . . . . . . . . 94
nuclear reactions
531
compared to chemical reactions 388
definition of . . . . . . . . . . . . . . . . . . . 388
energy sources . . . . . . . . . . . . . . . . 391
examples of . . . . . . . . . . . . . . . . . . . 391
fission . . . . . . . . . . . . . . . . . . . . . . . . . 387
fusion . . . . . . . . . . . . . . . . . . . . . . . . . 387
medical uses . . . . . . . . . . . . . . . . . . 393
nucleons . . . . . . . . . . . . . . . . . . . . . . 388
radioactivity . . . . . . . . . . . . . . . . . . . 390
nucleus . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
phase of . . . . . . . . . . . . . . . . . . . . . . . 186
vibrating strings . . . . . . . . . . . . . . . 188
Otto, Nikolaus . . . . . . . . . . . . . . . . . . . . 495
output force . . . . . . . . . . . . . . . . . . . . . 68, 69
oxidation number
definition of . . . . . . . . . . . . . . . . . . . 334
predicting . . . . . . . . . . . . . . . . . . . . . 335
O
parallel circuits . . . . . . . . . . . . . . . . 150–152
pendulums . . . . . . . . . . . . . . . . . . . . . . . . 188
percent yield . . . . . . . . . . . . . . . . . . . . . . 368
periodic table of elements
atomic mass . . . . . . . . . . . . . . . . . . . 322
atomic number . . . . . . . . . . . . . . . . 322
chemical symbols . . . . . . . . . . . . . 322
description of . . . . . . . . . . . . . . . . . 316
determining oxidation numbers 335
groups of elements . . . . . . . . . . . . 320
history of . . . . . . . . . . . . . . . . . . . . . . 321
how to read it . . . . . . . . . . . . . . . . . 322
mass number . . . . . . . . . . . . . . . . . . 322
Mendeleev, Dimitri . . . . . . . . . . . 321
organization of . . . . . . . . . . . . . . . . 329
see also back cover
periods of cycles
calculating . . . . . . . . . . . . . . . . . . . . 182
definition of . . . . . . . . . . . . . . . . . . . 182
determining from a graph . . . . . 185
of harmonic motion . . . . . . . . . . . 182
permanent magnets . . . . . . . . . . . 159, 170
Petit, Alexis Therese . . . . . . . . . . . . . . 460
octet rule for valence electrons . . . . 327
ohm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Ohm, Georg S. . . . . . . . . . . . . . . . . 124, 131
Ohm’s law . . . . . . . . . . . . . . . . . . . . . . . . 131
Onnes, Heike Kamerlingh . . . . . . . . . 134
open circuits . . . . . . . . . . . . . . . . . . . . . . 104
optical illusions . . . . . . . . . . . . . . . . . . . 266
optical system . . . . . . . . . . . . . . . . . . . . . 258
optics
critical angle . . . . . . . . . . . . . . . . . . 268
definition of . . . . . . . . . . . . . . . . . . . 255
optical system . . . . . . . . . . . . . . . . . 258
prism . . . . . . . . . . . . . . . . . . . . . . 255, 263
reflection . . . . . . . . . . . . . . . . . . . . . . 258
refraction . . . . . . . . . . . . . . . . . . 258, 261
virtual images . . . . . . . . . . . . . . . . . 260
oscillators
in harmonic motion . . . . . . . . . . . 180
mass on a spring . . . . . . . . . . . . . . 188
pendulums . . . . . . . . . . . . . . . . . . . . 188
532
P
petroleum . . . . . . . . . . . . . . . . . . . . . . . . . 364
pH
definition of . . . . . . . . . . . . . . . . . . . 439
indicator . . . . . . . . . . . . . . . . . . . . . . 442
of blood . . . . . . . . . . . . . . . . . . . . . . . 443
of common chemicals . . . . . . . . . 442
pH scale . . . . . . . . . . . . . . . . . . . . . . . . . . 439
pH test . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431
phosphate test . . . . . . . . . . . . . . . . . . . . . 431
photocopier . . . . . . . . . . . . . . . . . . . . . . . 124
photoreceptors . . . . . . . . . . . . . . . . . . . . 243
photosynthesis . . . . . . . . . . . . . . . . . . . . 394
physical changes
compared to chemical changes 353
definition of . . . . . . . . . . . . . . . . . . . 353
physical models . . . . . . . . . . . . . . . . . . . . 25
pitch in music . . . . . . . . . . . . . . . . . . . . . 224
plane waves . . . . . . . . . . . . . . . . . . . . . . . 200
plastics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Plucker, Julius . . . . . . . . . . . . . . . . . . . . 313
polarization . . . . . . . . . . . . . . . . . . . . . . . 240
polarizer . . . . . . . . . . . . . . . . . . . . . . . . . . 240
polyatomic ions . . . . . . . . . . . . . . . . . . . 337
polymers . . . . . . . . . . . . . . . . . . 333, 356, 408
position vs. time graph . . . . . . . . . . . . . 30
positive charge . . . . . . . . . . . . . . . . . . . . 105
potable water . . . . . . . . . . . . . . . . . . . . . 403
potential energy
calculating . . . . . . . . . . . . . . . . . . . . . 88
chemical . . . . . . . . . . . . . . . . . . . . . . . 91
definition of . . . . . . . . . . . . . . . . . . . . 88
potentiometer . . . . . . . . . . . . . . . . . . . . . 136
pounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
power
Q
quantum theory . . . . . . . . . . . . . . . . . . . 319
Queen Elizabeth I . . . . . . . . . . . . . . . . . 108
R
radiant energy . . . . . . . . . . . . . . . . . . . . . . 93
radiation
absorption . . . . . . . . . . . . . . . . . . . . . 476
electromagnetic . . . . . . . . . . . . 93, 474
emission . . . . . . . . . . . . . . . . . . . . . . . 476
nuclear . . . . . . . . . . . . . . . . . . . . . . . . 390
radio waves . . . . . . . . . . . . . . . . . . . . . . . 237
radioactive isotopes . . . . . . . . . . . . . . . 393
radioactivity . . . . . . . . . . . . . . . . . . . . . . . 390
ratios in chemical equations . . . . . . . 366
ray diagrams . . . . . . . . . . . . . . . . . . . . . . 259
reactions
see also carbon reactions
see also chemical reactions
see also combustion reactions
see also nuclear reactions
real image . . . . . . . . . . . . . . . . . . . . . . . . . 262
recycling
plastics . . . . . . . . . . . . . . . . . . . . . . . . 333
steel . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
reflection
as a wave action . . . . . . . . . . . . . . . 201
in optical systems . . . . . . . . . . . . . 258
law of . . . . . . . . . . . . . . . . . . . . . . . . . 260
refraction
as a wave action . . . . . . . . . . . 201, 202
in optical systems . . . . . . . . . . . . . 258
relative mass . . . . . . . . . . . . . . . . . . . . . . 341
resistance
definition of . . . . . . . . . . . . . . . . . . . 123
in circuits . . . . . . . . . . . . . . . . . . . . . . 123
ohm . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
resistors
fixed value . . . . . . . . . . . . . . . . . . . . 135
variable value . . . . . . . . . . . . . . . . . 135
resonance . . . . . . . . . . . . . . . . . . . . . . . . . 204
definition of . . . . . . . . . . . . . . . . . . . 204
relationship to amplitude . . . . . . 204
reverberation . . . . . . . . . . . . . . . . . . . . . . 223
RGB color process . . . . . . . . . . . . . . . . 248
rhythm in music . . . . . . . . . . . . . . . . . . . 224
Roemer, Ole . . . . . . . . . . . . . . . . . . . . . . 452
rolling friction . . . . . . . . . . . . . . . . . . . . . . 56
Rutherford, Ernest . . . . . . . . . . . . . . . . . 313
S
safety glass . . . . . . . . . . . . . . . . . . . . . . . . 293
saturated solutions . . . . . . . . . . . . . . . . 414
Schrodinger, Erwin . . . . . . . . . . . . . . . . 314
scientific method . . . . . . . . . . . . . . . . . . . . 9
sea breezes . . . . . . . . . . . . . . . . . . . . . . . . 471
semiconductors . . . . . . . . . . . . . . . . . . . 121
series circuits . . . . . . . . . . . . . . . . . . 147–149
short circuits . . . . . . . . . . . . . . . . . . 104, 152
simple machines
definition of . . . . . . . . . . . . . . . . . . . . 68
forces . . . . . . . . . . . . . . . . . . . . . . . . . . 69
single-displacement reactions . . . . . 377
sliding friction . . . . . . . . . . . . . . . . . . . . . 56
solar power . . . . . . . . . . . . . . . . . . . . . . . . . 93
solids
brittleness . . . . . . . . . . . . . . . . . . . . . 293
density . . . . . . . . . . . . . . . . . . . . . . . . 291
elasticity . . . . . . . . . . . . . . . . . . . . . . 292
hardness . . . . . . . . . . . . . . . . . . . . . . . 292
malleability . . . . . . . . . . . . . . . . . . . 294
properties of . . . . . . . . . . . . . . . . . . . 291
tensile strength . . . . . . . . . . . . . . . . 294
solubility
achieving equilibrium . . . . . . . . . 414
definition of . . . . . . . . . . . . . . . . . . . 411
effects of pressure on . . . . . . . . . . 413
effects of temperature on . . 411, 412
effects of volume on . . . . . . . . . . . 411
of gases . . . . . . . . . . . . . . . . . . . . . . . 413
solubility rules . . . . . . . . . . . . . . . . . . . . 423
solubility value . . . . . . . . . . . . . . . . . . . . 411
Index
calculating . . . . . . . . . . . . . . . . . . . . . . 86
definition of . . . . . . . . . . . . . . . . 86, 137
precipitate . . . . . . . . . . . . . . . . . . . . . . . . . 377
precipitation . . . . . . . . . . . . . . . . . . . . . . . 426
acid . . . . . . . . . . . . . . . . . . . . . . . . . . . 444
cloud seeding . . . . . . . . . . . . . . . . . . 428
definition of . . . . . . . . . . . . . . . . . . . 426
primary colors . . . . . . . . . . . . . . . . . 243, 244
prisms . . . . . . . . . . . . . . . . . . . . . . . . . 255, 263
proteins . . . . . . . . . . . . . . . . . . . . . . . . . . . 488
protons . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Ptolemy Philadelphos . . . . . . . . . . . . . . 25
533
solubility-temperature graphs . . . . . 412
solutions
definition of . . . . . . . . . . . . . . . . . . . 404
dissolving rate of . . . . . . . . . . . . . . 406
properties of . . . . . . . . . . . . . . . . . . . 405
saturated . . . . . . . . . . . . . . . . . . . . . . 414
solute . . . . . . . . . . . . . . . . . . . . . . . . . 404
solvent . . . . . . . . . . . . . . . . . . . . . . . . 404
supersaturated . . . . . . . . . . . . . . . . . 414
Tyndall effect . . . . . . . . . . . . . . . . . 405
unsaturated . . . . . . . . . . . . . . . . . . . . 414
sonograms . . . . . . . . . . . . . . . . . . . . . . . . 220
sound
acoustics . . . . . . . . . . . . . . . . . . . . . . 218
frequency . . . . . . . . . . . . . . . . . . . . . 219
how we hear . . . . . . . . . . . . . . . . . . . 213
loudness . . . . . . . . . . . . . . . . . . . . . . . 217
properties of . . . . . . . . . . . . . . . 215, 217
resonance . . . . . . . . . . . . . . . . . . . . . 204
sonograms . . . . . . . . . . . . . . . . . . . . 220
speed of . . . . . . . . . . . . . . . . . . . . . . . 222
wavelength of . . . . . . . . . . . . . . . . . 221
waves . . . . . . . . . . . . . . . . . . . . . . . . . 213
white noise . . . . . . . . . . . . . . . . . . . . 220
specific heat . . . . . . . . . . . . . . .457, 458, 459
spectral diagram . . . . . . . . . . . . . . . . . . 475
speed
average . . . . . . . . . . . . . . . . . . . . . . . . . 32
calculating . . . . . . . . . . . . . . . . . . . . . 15
common units of . . . . . . . . . . . . . . . 14
definition of . . . . . . . . . . . . . . . . . . . . 13
instantaneous . . . . . . . . . . . . . . . . . . . 32
of light . . . . . . . . . . . . . . . . . . . . . . . . 239
of sound . . . . . . . . . . . . . . . . . . . . . . . 222
534
of waves . . . . . . . . . . . . . . . . . . . . . . 199
relationship of time and distance to
27
speed vs. time graph . . . . . . . . . . . . . . . 38
spinal cord injuries . . . . . . . . . . . . . . . . 104
standing waves . . . . . . . . . . . . . . . . . . . . 205
Starley, James . . . . . . . . . . . . . . . . . . . . . . 85
Stevinus, Simon . . . . . . . . . . . . . . . . . . . . 34
Strato . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
strong nuclear force . . . . . . . . . . . . . . . 317
subatomic particles . . . . . . . . . . . . . . . . 311
substances . . . . . . . . . . . . . . . . . . . . . . . . 278
subtractive primary colors . . . . . . . . . 246
superconductivity . . . . . . . . . . . . . . . . . 134
supersaturated solutions . . . . . . . . . . . 414
surface runoff . . . . . . . . . . . . . . . . . . . . . 426
surface water . . . . . . . . . . . . . . . . . . . . . . 426
suspensions, properties of . . . . . . . . . 405
synthesis . . . . . . . . . . . . . . . . . . . . . . . . . . 394
systems
in harmonic motion . . . . . . . . . . . 180
open vs. closed . . . . . . . . . . . . . . . . 409
optical . . . . . . . . . . . . . . . . . . . . . . . . . 258
solutes and solvents . . . . . . . . . . . 409
T
tap water . . . . . . . . . . . . . . . . . . . . . . . . . . 424
technology
definition of . . . . . . . . . . . . . . . . . . . . 73
electric cars . . . . . . . . . . . . . . . . . . . 138
harmonic motion . . . . . . . . . . . . . . 181
optical . . . . . . . . . . . . . . . . . . . . . . . . . 267
photocopier . . . . . . . . . . . . . . . . . . . 124
superconductivity . . . . . . . . . . . . . 134
voice recognition . . . . . . . . . . . . . . 220
temperature
definition of . . . . . . . . . . . . . . . 284, 451
effect on conductors . . . . . . . . . . . 134
effect on molecules . . . . . . . . . . . . 284
effect on solubility . . . . . . . . 411, 412
effect on viscosity . . . . . . . . . . . . . 303
measuring with thermometers . 453
of Earth . . . . . . . . . . . . . . . . . . . 483, 484
relationship to color . . . . . . . . . . . 474
thermal equilibrium . . . . . . . . . . . 458
temperature scales
Celsius . . . . . . . . . . . . . . . . . . . . . . . . 452
Fahrenheit . . . . . . . . . . . . . . . . . . . . . 452
temperature-solubility graphs . . . . . 412
tensile strength . . . . . . . . . . . . . . . . . . . . 294
terahertz . . . . . . . . . . . . . . . . . . . . . . . . . . 242
thermal conductivity . . . . . . . . . . 467, 469
thermal conductors . . . . . . . . . . . . . . . . 468
thermal energy . . . . . . . . . . . . . . . . . 93, 481
thermal equilibrium . . . . . . . . . . . . . . . 458
thermal insulators . . . . . . . . . . . . . . . . . 468
thermodynamics, first law of . . . . . . 458
thermometers . . . . . . . . . . . . . . . . . . . . . 453
thermostat . . . . . . . . . . . . . . . . . . . . . . . . . 454
third law of motion . . . . . . . . . . . . . . . . . 59
Thomson, Joseph John . . . . . . . . . . . . 313
time
definition of . . . . . . . . . . . . . . . . . . . . 14
measurements of . . . . . . . . . . . . . . . . 4
transpiration . . . . . . . . . . . . . . . . . . . . . . 426
transverse waves . . . . . . . . . . . . . . . . . . 197
troughs of waves . . . . . . . . . . . . . . . . . . 200
Tyndall effect . . . . . . . . . . . . . . . . . . . . . 405
ultraviolet waves . . . . . . . . . . . . . . . . . . 238
unsaturated solutions . . . . . . . . . . . . . . 414
utility companies . . . . . . . . . . . . . . . . . . 139
V
valence electrons
definition of . . . . . . . . . . . . . . . . . . . 321
dot diagrams . . . . . . . . . . . . . . . . . . 330
octet rule . . . . . . . . . . . . . . . . . . . . . . 327
periodic table . . . . . . . . . . . . . . . . . . 329
variable
control . . . . . . . . . . . . . . . . . . . . . . . . . 11
definition of . . . . . . . . . . . . . . . . . . . . 11
dependent . . . . . . . . . . . . . . . . . . . . . . 26
experimental . . . . . . . . . . . . . . . . . . . 11
independent . . . . . . . . . . . . . . . . . . . . 26
variable resistors . . . . . . . . . . . . . . . . . . 135
velocity
definition of . . . . . . . . . . . . . . . . . . . . 15
virtual image . . . . . . . . . . . . . . . . . . . . . . 262
virtual images . . . . . . . . . . . . . . . . . . . . . 260
viscosity
definition of . . . . . . . . . . . . . . . . . . . 302
effect of temperature on . . . . . . . 303
viscous friction . . . . . . . . . . . . . . . . . . . . . 56
visible light . . . . . . . . . . . . . . . . . . . 237, 238
W
water
as a solvent . . . . . . . . . . . . . . . . . . . . 421
carbonated . . . . . . . . . . . . . . . . . . . . . 403
distilled . . . . . . . . . . . . . . . . . . . . . . . 403
distribution on Earth . . . . . . . . . . . 429
mineral . . . . . . . . . . . . . . . . . . . . . . . . 403
potable . . . . . . . . . . . . . . . . . . . . . . . . 403
tap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424
water cycle . . . . . . . . . . . . . . . . . . . . 425, 426
water quality
biological oxygen demand test . 431
description of . . . . . . . . . . . . . . . . . . 430
determining . . . . . . . . . . . . . . . . . . . 430
dissolved oxygen test . . . . . . . . . . 430
nitrate test . . . . . . . . . . . . . . . . . . . . . 431
pH test . . . . . . . . . . . . . . . . . . . . . . . . 431
phosphate test . . . . . . . . . . . . . . . . . 431
turbidity test . . . . . . . . . . . . . . . . . . . 431
watt . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86, 137
Watt, James . . . . . . . . . . . . . . . . . . . . 86, 493
wave fronts . . . . . . . . . . . . . . . . . . . . . . . . 200
wavelength
measuring . . . . . . . . . . . . . . . . . . . . . 198
of light waves . . . . . . . . . . . . . . . . . 242
of sound waves . . . . . . . . . . . . . . . . 221
waves . . . . . . . . . . . . . . . . . . . . . . . . . 195, 242
absorption . . . . . . . . . . . . . . . . . . . . . 202
amplitude . . . . . . . . . . . . . . . . . . . . . 198
circular . . . . . . . . . . . . . . . . . . . . . . . . 200
constructive interference . . . . . . 206
description of . . . . . . . . . . . . . . . . . . 195
destructive interference . . . . . . . . 206
determining speed of . . . . . . . . . . 199
diffraction . . . . . . . . . . . . . . . . . . . . . 202
examples of . . . . . . . . . . . . . . . . . . . 196
frequency . . . . . . . . . . . . . . . . . . . . . 198
infrared . . . . . . . . . . . . . . . . . . . . . . . . 238
interference . . . . . . . . . . . . . . . . . . . 206
light . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
longitudinal . . . . . . . . . . . . . . . . . . . 197
plane . . . . . . . . . . . . . . . . . . . . . . . . . . 200
properties of . . . . . . . . . . . . . . . . . . . 198
reflection . . . . . . . . . . . . . . . . . . . . . . 201
refraction . . . . . . . . . . . . . . . . . . . . . . 202
standing . . . . . . . . . . . . . . . . . . . . . . . 205
transverse . . . . . . . . . . . . . . . . . . . . . 197
uses for . . . . . . . . . . . . . . . . . . . . . . . . 237
wavelength . . . . . . . . . . . . . . . . . . . . 198
weather
effect of bodies of water on . . . . 484
fronts . . . . . . . . . . . . . . . . . . . . . . . . . . 486
Index
U
voice recognition software . . . . . . . . 220
volcanoes . . . . . . . . . . . . . . . . . . . . . . . . . 484
volt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Volta, Alessandro . . . . . . . . . . . . . . . . . 115
voltage
description of . . . . . . . . . . . . . . . . . . 113
Kirchhoff’s law . . . . . . . . . . . . . . . 149
lightning . . . . . . . . . . . . . . . . . . . . . . 123
measuring . . . . . . . . . . . . . . . . . . . . . 115
volt . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
volume
calculating . . . . . . . . . . . . . . . . . . . . . 280
measuring . . . . . . . . . . . . . . . . . . . . . 280
535
global heating and cooling . . . . 481
global warming . . . . . . . . . . . . . . . 482
humidity . . . . . . . . . . . . . . . . . . . . . . 485
seasons . . . . . . . . . . . . . . . . . . . . . . . . 483
weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
whales . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
white noise . . . . . . . . . . . . . . . . . . . . . . . . 220
Williamson, J. Michael . . . . . . . . . . . . 304
work . . . . . . . . . . . . . . . . . . . . . . . . . . . 83, 137
calculating . . . . . . . . . . . . . . . . . . . . . 83
definition of . . . . . . . . . . . . . . . . . . . . 83
efficiency of machines . . . . . . . . . 85
input . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
output . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Wright, Wilbur and Orville . . . . . . . . 85
X
X rays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Y
yellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
536

lApplying Your Knowledge

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