Sample Questions

Grade 8
Texas
Science
Essential Knowledge and Skills
Reviewers
Vanessa Contrares • Rayford Intermediate School • Aldine Independent School District
Karri Dawes • Pearson Elementary School • Garland Independent School District
Elizabeth Donovan • Griffin Middle School • Frisco Independent School District
Starlette Gerik • T. A. Howard Middle School • Mansfield Independent School District
Laura Grannell • Rodriguez Elementary School • Austin Independent School District
Catha Ivy • Colony Meadows Elementary • Fort Bend Independent School District
Toni Jones • Scobee Middle School • Southwest Independent School District
Linda Lyles • Larry G. Smith Elementary • Dallas Independent School District
Lynda Marazzini • Elma Neal Elementary • San Antonio Independent School District
Maria Moreno • Rico Elementary • Weslaco Independent School District
Sonia Rodas • Hedrick Elementary • Lewisville Independent School District
Antoinette Syler • Pearland Junior High East • Pearland Independent School District
Marti Turner • Waco ISD Curriculum Department • Waco Independent School District
Ieshia Webb • Alief Learning Center • Alief Independent School District
© 2012 Perfection Learning®
www.perfectionlearning.com
All rights reserved. No part of this book may be reproduced, stored in a retrieval
system, or transmitted in any form or by any means, electronic, mechanical,
photocopying, recording, or otherwise, without the prior permission of the publisher.
For information regarding permissions, write to: Permissions Department,
Perfection Learning, 2680 Berkshire Parkway, Des Moines, Iowa 50325.
1 2 3 4 5 6 PP 16 15 14 13 12 11
PP/Logan, Iowa, USA
8/11
35406
ISBN-10: 0-7891-8232-7
ISBN-13: 978-0-7891-8232-6
Printed in the United States of America
To the Student
Soon you will be taking assessments of academic readiness for science. This Better
Test Scores book will give you the practice and confidence you need to do well on this
important test. Here are the steps to follow to use this book.
1. Take Tryout Test 1 and check your answers. Use the chart at the bottom of this
page to find out your strengths and weaknesses in the science areas assessed.
Don’t be discouraged if you don’t get all of the answers right or if you don’t
understand some questions. Remember the hard questions. They will be the types
of questions you need to work on the most.
2. Work through the lessons that follow Tryout Test 1. These lessons will help you
with the kinds of questions you will be asked on the assessments of academic
readiness for science. Each lesson ends with a short practice test to reinforce
your new skills. Fill in the Keeping Score chart on page 85 as you complete each
practice test.
3. After completing all 7 lessons, take Tryout Test 2. Your score on this test will show
how much your test-taking skills have improved.
By following the steps outlined above, you will learn many of the skills you need to
do well on the assessments of academic readiness in science.
Lesson
Tryout Test 1
Tryout Test 2
1 Matter and Energy I
1, 2, *5, *6, 7, 8, 10
*2, 3, *4, *5, 8, *9, 12
2 Matter and Energy II
3, 4, 9, *11, *12, *13, *14
*1, *6, 7, *10, *11, 13, 14
3 Force, Motion, and Energy
*15, *16, *17, 18, *19, *20,
*21, 22, 23, *24, *25, *26
*15, 16, 17, *18, *19, *20,
*21, *22, *23, *24, *25, *26
4 Earth and Space I
27, 28, *29, 30, *31, 32, 33,
34
*27, 28, 29, 30, *31, 32, 33,
*34
*35, 36, *37, 38, 39, *40
35, *36, 37, *38, 39, *40
6 Organisms and Environments I
*41, 42, *43, 44, 45, *46,
*47, 49, *54
*41, 42, *43, 44, *45, *46,
*47, *53, 54
7 Organisms and Environments II
*48, *50, 51, 52, *53
48, 49, 50, *51, 52
(Reporting Category 1)
(Reporting Category 1)
(Reporting Category 2)
(Reporting Category 3)
5 Earth and Space II
(Reporting Category 3)
(Reporting Category 4)
(Reporting Category 4)
2 To the Student
© Perfection Learning® No reproduction permitted.
SCIENCE
Grade
Table of Contents
To the Student. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
LESSONS AND TESTS
Tryout Test 1 .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Take this sample test to find out what you know and don’t know.
Reporting Category 1: Matter and Energy
Lesson 1: Matter and Energy I [TEKS: 8.5(A), 8.5(B), 8.5(C), 8.5(D), 8.5(E),
8.5(F), 7.5(C), 7.6(A), 7.6(B), 6.5(C), 6.6(A), 6.6(B)]
Describe the structure of atoms, including the masses, electrical charges, and locations,
of protons and neutrons in the nucleus and electrons in the electron cloud; identify that
protons determine an element’s identity and valence electrons determine its chemical
properties, including reactivity; interpret the arrangement of the Periodic Table, including
groups and periods, to explain how properties are used to classify elements. Differentiate
between elements and compounds on the most basic level. Compare metals, nonmetals,
and metalloids using physical properties such as luster, conductivity, or malleability; and
calculate density to identify an unknown substance... . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Lesson 2:Matter and Energy II [TEKS: 8.5(A), 8.5(B), 8.5(C), 8.5(D), 8.5(E),
8.5(F), 7.5(C), 7.6(A), 7.6(B), 6.5(C), 6.6(A), 6.6(B)]
Recognize that chemical formulas are used to identify substances and determine the
number of atoms of each element in chemical formulas containing subscripts; investigate
how evidence of chemical reactions indicate that new substances with different properties
are formed; and recognize whether a chemical equation containing coefficients is balanced
or not and how that relates to the law of conservation of mass. Diagram the flow of energy
through living systems, including food chains, food webs, and energy pyramids; identify
that organic compounds contain carbon and other elements such as hydrogen, oxygen,
phosphorus, nitrogen, or sulfur; and distinguish between physical and chemical changes in
matter in the digestive system. ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
continued
© Perfection Learning® No reproduction permitted.
Table of Contents 3
LESSONS AND TESTS continued
Reporting Category 2: Force, Motion, and Energy
Lesson 3:Force, Motion, and Energy [TEKS: 8.6(A), 8.6(B), 8.6(C), 7.7(A),
6.8(A), 6.8(C), 6.8(D), 6.9(C)]
Demonstrate and calculate how unbalanced forces change the speed or direction of an
object’s motion; differentiate between speed, velocity, and acceleration; and investigate
and describe applications of Newton’s law of inertia, law of force and acceleration, and
law of action-reaction such as in vehicle restraints, sports activities, amusement park
rides, Earth’s tectonic activities, and rocket launches. Contrast situations where work
is done with different amounts of force to situations where no work is done such as
moving a box with a ramp and without a ramp, or standing still. Compare and
contrast potential and kinetic energy; calculate average speed using distance and
time measurements; and measure and graph changes in motion. Demonstrate energy
transformations such as energy in a flashlight battery changes from chemical energy
to electrical energy to light energy.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Reporting Category 3: Earth and Space
Lesson 4: Earth and Space I [TEKS: 8.7(A), 8.7(B), 8.7(C), 8.8(A), 8.8(B), 8.8(C),
8.8(D), 6.11(B)]
Model and illustrate how the tilted Earth rotates on its axis, causing day and night,
and revolves around the Sun causing changes in seasons; demonstrate and predict the
sequence of events in the lunar cycle; and relate the position of the Moon and Sun to
their effect on ocean tides. Describe components of the universe, including stars, nebulae,
and galaxies, and use models such as the Hertzsprung-Russell diagram for classification;
recognize that the Sun is a medium-sized star near the edge of a disc-shaped galaxy of
stars and that the Sun is many thousands of times closer to Earth than any other star;
explore how different wavelengths of the electromagnetic spectrum such as light and
radio waves are used to gain information about distances and properties of components
in the universe; and model and describe how light years are used to measure distances
and sizes in the universe. Understand that gravity is the force that governs the motion
of our solar system... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Lesson 5:Earth and Space II [TEKS: 8.9(A), 8.9(B), 8.9(C), 8.10(A), 8.10(B),
8.10(C), 7.8(C)]
Describe the historical development of evidence that supports plate tectonic theory; relate
plate tectonics to the formation of crustal features; and interpret topographic maps and
satellite views to identify land and erosional features and predict how these features
may be reshaped by weathering. Recognize that the Sun provides the energy that drives
convection within the atmosphere and oceans, producing winds and ocean currents;
identify how global patterns of atmospheric movement influence local weather using
weather maps that show high and low pressures and fronts; and identify the role of
the oceans in the formation of weather systems such as hurricanes. Model the effects
of human activity on groundwater and surface water in a watershed... . . . . . . . . . . . . . . . 47
4 Table of Contents © Perfection Learning® No reproduction permitted.
LESSONS AND TESTS continued
Reporting Category 4: Organisms and Environments
Lesson 6: Organisms and Environments I [TEKS: 8.11(A), 8.11(B), 8.11(C),
8.11(D), 7.10(B), 7.10(C)]
Describe producer/consumer, predator/prey, and parasite/host relationships as they occur
in food webs within marine, freshwater, and terrestrial ecosystems; investigate how
organisms and populations in an ecosystem depend on and may compete for biotic and
abiotic factors such as quantity of light, water, range of temperatures, or soil composition;
explore how short- and long-term environmental changes affect organisms and traits
in subsequent populations; and recognize human dependence on ocean systems and
explain how human activities such as runoff, artificial reefs, or use of resources have
modified these systems. Describe how biodiversity contributes to the sustainability of
an ecosystem; and observe, record, and describe the role of ecological succession such as
in a microhabitat of a garden with weeds.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Lesson 7: Organisms and Environments II [TEKS: 7.11(A), 7.11(C), 7.12(B),
7.12(D), 7.12(F), 7.14(B), 7.14(C), 6.12 (D)]
Examine organisms or their structures such as insects or leaves and use dichotomous
keys for identification; and identify some changes in genetic traits that have occurred over
several generations through natural selection and selective breeding such as the Galapagos
Medium Ground Finch (Geospiza fortis) or domestic animals. Identify the main functions
of the systems of the human organism, including the circulatory, respiratory, skeletal,
muscular, digestive, excretory, reproductive, integumentary, nervous, and endocrine
systems; differentiate between structure and function in plant and animal cell organelles,
including cell membrane, cell wall, nucleus, cytoplasm, mitochondrion, chloroplast, and
vacuole; and recognize that according to cell theory all organisms are composed of cells
and cells carry on similar functions such as extracting energy from food to sustain life.
Compare the results of uniform or diverse offspring from sexual reproduction or asexual
reproduction; and recognize that inherited traits of individuals are governed in the
genetic material found in the genes within chromosomes in the nucleus. Identify the
basic characteristics of organisms, including prokaryotic or eukaryotic, unicellular or
multicellular, autotrophic or heterotrophic, and mode of reproduction, that further
classify them in the currently recognized Kingdoms.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Tryout Test 2
Take this sample test to find out what you’ve learned... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Keeping Score.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Finding Percent .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
© Perfection Learning® No reproduction permitted.
Table of Contents
5
SCIENCE
Lesson
SCIENCE
SCIENCE
Matter
and Energy Le
I sson
Lesson
SCIENCE
Lesson
The assessments for science
will ask you
SCIENCE
Lesson
to . . .
•describe the structure of atoms
;
•identify that protons determine
an element’s identity and
valence electrons determine its
chemical properties, including
reactivity;
•interpret the arrangement of the
Periodic Table to explain
how properties are used to classify
SCIENCE
elem
ents;
E
C
N
E
I
C
S
•dSiffe
tiat
CeEbetween elements and
Lesson
IEN
C ren
compounds on the most
on
ss
Le
basic
lev
el;
on
Less
•compare metals, nonmetals, and
metalloids using physical
properties such as luster, conduc
tivity, or malleability; and
•calculate density to identify an
unknown substance.
Directions: Read each question and choose the best answer. Then mark the letter for the
answer you have chosen.
SCIENCE
SCIENCE
SCIENCE
Lesson
sscalled a—
Leis
C E table below, theLehighlighted
E Nperiodic
C Ithe
1 S
On
set of elements
sson
on
Lesson
SCIENCE
Lesson
A
family.
B
period.
C
formula.
D
complex
compound.
E
IENC
SC
Lesson
20 Matter and Energy I
SCIENCE
Lesson
SCIENCE
Lesson
SCIENCE
SCIENCE
Lesson
SCIENCE
Lesson
© Perfection Learning® No reproduction permitted.
Lesson
SCIENCE
Lesson
Example 1 asks you to identify a grouping of elements on the periodic table.
Elements are grouped horizontally into periods according to their atomic number. But the
illustration highlights a column, so choice B is incorrect. Elements in the periodic table are
grouped vertically as families or groups according to the physical or chemical properties
that they share. Choice A is the correct answer. Choices C and D list other ways that
elements can be described or interact that are not directly related to the periodic table.
Make sure to familiarize yourself with the periodic table. Most of the elements in the
table are metals. They are called transitional elements. Elements in the top right corner of
the table (including carbon, phosphorus, selenium, iodine, astatine, radon, and the elements
to the right and above them, plus hydrogen) are all nonmetals. The elements between
the metals and nonmetals (boron, silicon, germanium, arsenic, antimony, and tellurium)
are metalloids. Metalloids share properties with both metals and nonmetals. As elements
go from left to right along the table, they increase in atomic mass. The horizontal rows
are called periods. Elements that share similar properties are placed in the same vertical
column, or group.
© Perfection Learning® No reproduction permitted.
Matter and Energy I 21
2 The illustration below shows a model of a carbon atom. What particles are represented
by the cloud that surrounds the central mass?
F
atoms
G
electrons
H
neutrons
J
protons
3 The carbon atom shown in question 2 has six protons, six neutrons, and six electrons.
What is its atomic number?
A
6
B
12
C
18
D
36
4 Chromium is a(n)—
F
compound.
G
element.
H
formula.
J
reaction.
Example 2 asks you to examine a model of an atom and tell which atomic particles
are represented by the cloud that surrounds the center, or nucleus. Choice H, neutrons,
and choice J, protons, are both incorrect because neutrons and protons are both located
within the nucleus. Choice F is incorrect because the entire model is of an atom. Choice G,
electrons, is the correct answer. Electrons orbit the nucleus of an atom.
22 Matter and Energy I
© Perfection Learning® No reproduction permitted.
A typical atom is shown below. The electrons orbit the nucleus and have a negative
charge. The protons and neutrons are found in the nucleus. Protons have a positive
charge, and neutrons have no charge.
Hint
Don’t confuse atomic number wit
h atomic mass.
Atomic number 5 number of
protons in an atom
Atomic mass 5 number of pro
tons 1 number of
neutrons in an atom
In Example 3, you are asked to identify the atomic number of the atom shown. The
atomic number is equal to the number of protons in the atom. The correct answer is 6,
choice A.
In Example 4, you are given the name of a substance and asked to determine if it is
a compound, an element, a formula, or a reaction. Chromium is a simple element; choice
G is correct. Choice F, compound, is a chemical combination of two or more elements.
Formula, choice H, is the relative number of atoms of each element in a compound.
Choice J, reaction, is the process that occurs when two or more substances interact,
undergoing a chemical change.
Remember . . .
between elements
To help remember the difference
words to chemical
and compounds, relate compound
word is made up of
compounds. Just as a compound
compound is made up
more than one part, a chemical
of more than one element.
Test-Taking Tips
1 Be familiar with the periodic table. Practice finding
elements and
determining the characteristics
each element has according to its
position on the table. Know wh
ere the metals, nonmetals, and
metalloids
are, as well as the characteristic
s that the elements in key groups
share.
2 Review the parts of the atom and their charges. Be
familiar with how
the numbers of protons, neutron
s, and electrons change the atomic
mass
and charge of an atom.
Go for it!
© Perfection Learning® No reproduction permitted.
Matter and Energy I 23
Test Practice 1
Test Practice 1: Matter and Energy I
Estimated time:
15 minutes
Directions: Read each question and choose the best answer. Then mark the letter for the answer
you have chosen.
1 Chlorine is added to some alcohol chemicals to make weed-killer. Some environmentalists
have concerns about the pollution it causes. Using the periodic table, which chemical
would you suspect might have similar properties and could possibly be substituted for
chlorine?
A
magnesium
B
carbon
C
chromium
D
bromine
2 Based on the periodic table shown above, which of the following elements has
the largest number of electrons in each atom?
F
molybdenum
G
rhenium
H
technetium
J
tungsten
3 Elements that are grouped between metals and nonmetals are called—
A
reactants.
B
gases.
C
metalloids.
D
synthetics.
24
© Perfection Learning® No reproduction permitted.
Test Practice 1
4 Which characteristic below is true of nonmetals?
F
They
G
They
H
They
J
They
are opaque.
are good conductors of electricity.
have a high luster.
are very brittle.
5 Which set of numbers correctly balances the equation using the smallest units possible?
H 2 O2
H2O 1
O2
A
1, 2, 1
B
2, 1, 2
C
1, 1, 2
D
2, 2, 1
6 Which of the following equations is NOT balanced?
F
C2H61O2
CO21H2O
G
AgNO3 1 NaI
AgI 1 NaNO3
H
Ca1Cl2
CaCl2
J
2Fe 1 3Cl2
2FeCl3
7 The difference between carbon-12 and carbon-13 atoms is the—
A
number of electrons.
B
number of neutrons.
C
number of protons.
D
charge of the atoms.
8 In a lithium atom (atomic number 3), where are electrons most likely to be located?
F
one electron near the nucleus and two electrons farther out
G two electrons near the nucleus and one electron farther out
H three electrons equidistant from the nucleus
J eight electrons, all at different distances from the nucleus
© Perfection Learning® No reproduction permitted.
25
Test Practice 1
9 What charge does a neutron particle
carry?
A
negative
B
positive
C
both positive and negative
D
no charge
10
A neutral atom of copper has 29 protons
and 34 neutrons. How many electrons
does it have? Record your answer and fill
in the bubbles on the grid.
.
11
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
4
5
6
7
8
9
4
5
6
7
8
9
4
5
6
7
8
9
4
5
6
7
8
9
4
5
6
7
8
9
4
5
6
7
8
9
Water has a density of 1.0 g/cm3.
Substances that are denser than water
sink when placed in water. Substances
less dense than water float when placed
in water. Which of the substances shown
in the table float in water?
Densities of
Several Common Substances
Substance
Density
diamond
3.5 gcm3
cork
0.34 gcm3
ice
0.92 gcm3
olive oil
0.9 gcm3
oak
0.7 gcm3
A
diamond only
B
cork only
C
cork, ice, olive oil, and oak
D
They all float.
Examine the model of a radon atom
shown below. What is its atomic mass?
F
43
G
86
H
172
J
258
26
12
Points Earned ⁄ Total = ______ ⁄ 12
© Perfection Learning® No reproduction permitted.