Is Kr the symbol for Kryptonite?

Section 3.1
The Elements
Is Kr the
symbol for
Kryptonite?
Section 3.1
The Elements
Objectives
1.  To learn about the relative abundances of the elements
2.  To learn the names of some elements
3.  To learn the symbols of some elements
What will Beryllium
r
o
f
s
i
F
e
n
i
r
o
Flu
Be?
Xe
Boron
=B
Carl Sagan - Everything
Section 3.1
The Elements
The Elements
•  All of the materials in the universe can be chemically
broken down into about 110 different elements.
•  Compounds are made by combining atoms of the
elements just as words are constructed from the letters in
the alphabet but rules apply to govern the combinations.
Words
Compounds
Section 3.1
The Elements
A. Abundances of Elements
•  Nine elements account for about 98% of the earth’s
crust, oceans and atmosphere.
Crust
Section 3.1
The Elements
A. Abundances of Elements
•  The elements in living matter are
very different from those in the
earth’s crust
•  In the human
body,
oxygen,
carbon,
hydrogen
and nitrogen
are the most
abundant
elements.
Section 3.1
The Elements
“Element” can have several scientific meanings
Element
Element
Element
Microscopic form
Single atom of that
element
Macroscopic form
Sample of that
element large enough
to weigh on a balance
Generic form
When we say the human body contains the element
sodium or lithium, we do not mean that free
elemental sodium or lithium is present. Rather we
mean that atoms of these elements are present in
some form.
Section 3.1
The Elements
B. Names and Symbols for the Elements
•  Each element has a name and a symbol.
–  The symbol usually consists of the first one or two
letters of the element’s name.
•  Examples:
Oxygen
Krypton
O
Kr
–  Sometimes the symbol is taken from the element’s
original Latin or Greek name.
•  Examples:
gold Au
lead Pb
aurum
plumbum
In your notes write the symbol of the 10 most common elements of the
Earth’s crust and in the human body next to their names
Section 3.1
The Elements
Element Hangman
Give the symbol for the following elements:
Carbon
Cobalt
Cesium
Calcium
Copper
Chlorine
Cadmium
Cerium
Section 3.1
The Elements
Objectives
1.  To understand and illustrate the Law of Constant
Composition
2.  To learn about Dalton’s theory of atoms
3.  To learn how a formula describes a compound’s
composition
Dalton Intro
Section 3.1
The Elements
1) Law of Constant Composition (1799 Joseph Louis Proust)
•  A given compound always contains the same proportion
by mass of the elements of which it is composed.
ü  A mixture can have variable composition but the
composition of a compound is fixed
ü  Does this give us a clue about the nature of matter?
H 2O = H 2O = H 2O = H 2O
Section 3.1
The Elements
2) Law of Multiple Proportions (1803 John Dalton)
•  Different compounds formed by two elements have whole
number ratios between their formulas
Section 3.1
The Elements
Dalton’s Atomic Theory (John Dalton 1766-1844)
Dalton’s Atomic Theory states:
−  All elements are composed of atoms
−  All atoms of a given element are identical
−  Atoms of different elements are different
−  Compounds consist of combinations of
atoms of different elements
−  Atoms are not created or destroyed in a
chemical reaction
You have 90 seconds to memorize these 5 parts of
the theory!!
Section 3.1
The Elements
Brownian Motion – Visual Evidence for Atoms
•  Observed by Robert Brown 1773-1858
Brownian Motion
•  Pollen particles on the surface of water
•  Used in 1905 by Einstein to support the existence of
atoms
Section 3.1
The Elements
Formulas of Compounds
•  A compound is represented by a chemical formula in
which the number and kind of atoms present is shown by
using the element symbols and subscripts.
Example: the simple sugar, glucose
Section 3.1
The Elements
Put your notes away and write a set of
rules for how to write a formula of a
compound. Be as complete as you can be
using what you have learned throughout
your course
Section 3.1
The Elements
B. Formulas of Compounds
1.  Each atom present is represented by its element symbol.
2.  The number of each type of atom is indicated by a subscript written to
the right of the element symbol.
3.  When only one atom of a given type is present, the subscript 1 is not
written.
4.  Write a metallic element first if present (MgCl2)
5.  Write the central atom of a molecule first (PCl5)
6.  Write Carbon first and Hydrogen second for an organic molecule
(C6H12O6)
Section 3.1
The Elements
Formulas of compounds
•  Write the formulas for the following compounds:
–  A phosphorus atom bonded to three chlorine atoms
–  A molecule containing two boron atoms and six
hydrogen atoms
–  A compound containing one calcium atom for every
two chlorine atoms
–  Four hydrogen atoms bonded to a single carbon atom
–  A compound containing two iron atoms for every three
oxygen atoms
–  A molecule of aspirin (acetylsalicylic acid – four
oxygen atoms, eight hydrogen, nine carbon atoms)
Section 3.1
The Elements
Aspirin, acetylsalicylic acid, C9H8O4
Aspirin in Motion
Element Hangman
Section 3.1
The Elements
Dalton described the
atomic nature of matter –
is that the end of the
story?
Section 3.1
The Elements
Objectives
1.  To learn more about how the understanding of atomic
structure developed
2.  To learn about the internal parts of an atom
3.  To understand Rutherford’s experiment
4.  To describe some important features of subatomic
particles
5.  To learn about the terms isotope, atomic number, and
mass number
6.  To understand the use of the symbol
to describe a
given atom
Section 3.1
The Elements
A. The Structure of the Atom
•  Experiments by J.J. Thomson in the 1890’s showed that
atoms contain electrons.
•  Cathode ray tube
The Discovery of
the Electron Electric Potential =
Voltage
Section 3.1
The Elements
A. The Structure of the Atom
The Plum Pudding (Chocolate Chip Cookie) Model
The Discovery of
the Electron Section 3.1
The Elements
A. The Structure of the Atom
Rutherford’s Experiment (1911)
α particles are very small and positively charged
Section 3.1
The Elements
A. The Structure of the Atom
•  Results of the Rutherford experiment
(a) The results that the metal foil
experiment would have yielded if the
plum pudding model had been correct
(b) Actual results
Section 3.1
The Elements
B. Introduction to the Modern Concept of Atomic
Structure
•  Ernest Rutherford showed that
atoms have internal structure.
–  The nucleus, which is at the
center of the atom, contains
protons (positively charged)
and neutrons (uncharged).
–  Negatively charged electrons
move around the nucleus.
The Discovery of the Atomic Nucleus Section 3.1
The Elements
B. Introduction to the Modern Concept of Atomic
Structure
Comparing the Parts of an Atom
Section 3.1
The Elements
Large
Hadron
Collider
Video √
BBC Video
Circular tunnel 27km in circumference near
Geneva
Protons or lead nucleii smashed into targets
$4 billion cost – limited operation to date
2011 Restart
Section 3.1
The Elements
C. Atoms and Isotopes
•  Atoms are made of protons neutrons and electrons
•  Atoms of an element all have the same number of protons –
the number of protons defines the atom as being of that
element
•  In a neutral atom the number of electrons equals the number
of protons – plus charge is balanced out by minus charge
•  However for a given element the number of neutrons can
vary from atom to atom
•  The different versions of atoms of an element are called
isotopes
•  Isotopes of an element all have the same chemical properties
Section 3.1
The Elements
C. Isotopes
•  Isotopes are atoms with the same number of protons but
different numbers of neutrons.
Draw a similar picture for 15N
Section 3.1
The Elements
C. Isotopes
•  A particular isotope is represented by the symbol
.
•  The atomic number, Z, shows the number of protons
•  The mass number, A, shows the number of protons plus
neutrons
e.g. Carbon: How many protons and
neutrons in each of 12C, 13C and 14C?
Section 3.1
The Elements
Isotopes
•  True or False? Atoms that have the same number of
neutrons but different numbers of protons are called
isotopes
•  True or False? The mass number of a nucleus
represents the number of protons in the nucleus
•  Are all atoms of the same element identical? If not, how
do they differ? Is this consistent with Dalton’s atomic
theory?
•  True or False? Isotopes of an element have different
chemical properties
•  True or False? All isotopes of an element are stable
Dynamic Periodic Table
Section 3.1
The Elements
Isotope Math
•  How Many Protons, Neutrons and Electrons in…..?
64
28Ni
48
22Ti
35Cl
11B
106Ag+
45Ca2+
Section 3.1
The Elements
More Isotope Math
•  What is the symbol for the isotopes below?
§  Z = 8, number of neutrons = 9
§  Isotope of chlorine with A = 37
§  Z = 27, A = 60
§  Number of protons = 26, number of neutrons = 31
§  The isotope of iodine with a mass number of 131
§  Z = 3, number of neutrons = 4
§  Z = 8, number of neutrons = 9, number of electrons = 10
•  WOC page 88 - Q30
Build An Atom
Section 3.1
The Elements
Objectives
1.  To learn some features of the Periodic Table
2.  To learn some of the properties of metals, nonmetals
and metalloids
3.  To learn the nature of the common elements
Section 3.1
The Elements
A. Introduction to the Periodic Table
•  The periodic table shows all of the known elements in
order of increasing atomic number.
Section 3.1
The Elements
A. Introduction to the Periodic Table
•  The periodic table is organized to group elements with
similar properties in vertical columns.
Section 3.1
The Elements
Introduction to the Periodic Table
•  Give the Symbol and Name of 5 Elements from the
following Groups
–  Halogens
–  Noble Gases
–  Alkali Metals
–  Transition Metals
–  Alkaline Earths
•  What is the Group number for
–  Oxygen
–  Nitrogen
–  Carbon
Section 3.1
The Elements
A. Introduction to the Periodic Table
•  Most elements are metals and occur on the left side.
•  The nonmetals appear on the right side.
•  Metalloids are elements that have some metallic and some nonmetallic properties.
Computer chips
Section 3.1
The Elements
A. Introduction to the Periodic Table
• 
Physical Properties of Metals
1.  Efficient conduction of heat and electricity
2.  Malleability (can be hammered into thin sheets)
3.  Ductility (can be pulled into wires)
4.  A lustrous (shiny) appearance
Section 3.1
The Elements
Tightest frying pan roll
The tightest circumference of a 30 centimeter
(12-inch) aluminium frying pan, rolled with bare
hands in 30 seconds is 17.46 centimeters (6.87
inches), set by Scott Murphy at the NXB Team
Training Center in Myrtle Beach, S.C., on July
30, 2007.
Guinness Book of Records
Section 3.1
The Elements
Elements in the Periodic Table
•  What is the symbol, group number, group name and
element classification for:–  Sodium
–  Iodine
–  Argon
–  Iron
–  Barium
–  Silicon
–  Uranium
–  Erbium
PT 1a from 3 minutes
PT 1b early attempts
PT 2a from 3 minutes
PT 2b explanation of PT
Section 3.1
The Elements
B. Natural States of the Elements
•  Most elements are very reactive.
•  Elements are not generally found in nature in
uncombined form.
–  Exceptions are:
•  Noble metals – gold, platinum and silver
•  Noble gases – Group 8
Section 3.1
The Elements
B. Natural States of the Elements
•  Diatomic Molecules
Nitrogen gas contains
N molecules.
2
Oxygen gas contains
O molecules.
2
Section 3.1
The Elements
B. Natural States of the Elements
•  Diatomic Molecules
Section 3.1
The Elements
HONClBrIF
HONClBrIF
HONC
lBrIF
HONClBrIF
Section 3.1
The Elements
B. Natural States of the Elements
•  Elemental Solids – Can exist as “Allotropes”
Carbon
atoms
Diamond
Graphite
Buckminsterfullerene
Section 3.1
The Elements
507-Carat Diamond Found at
South African Mine
Graphite
Diamond Planet
Section 3.1
The Elements
Elements in the Periodic Table
•  Give the element classification (metal, non-metal, metalloid)
and natural state (solid, liquid, gas) (atom, molecule)? of:
–  Potassium
–  Chlorine
–  Neon
–  Tungsten
–  Magnesium
–  Germanium
–  Iodine
–  Mercury
Section 3.1
The Elements
Objectives
1.  To describe the formation of ions from their parent
atoms
2.  To learn to name ions
3.  To predict which ion a given element forms by using
the periodic table
4.  To describe how ions combine to form neutral
compounds
+/-
e-
Section 3.1
The Elements
A. Ions
•  In a chemical reaction atoms can form ions by gaining or
losing electrons.
–  Metals tend to lose one or more electrons to form
positive ions called cations.
–  Cations are generally named by using the name of the parent atom.
Section 3.1
The Elements
A. Ions
•  Nonmetals tend to gain one or more electrons to form
negative ions called anions.
• 
Anions are named by using the root of the atom name followed by the suffix –ide.
Section 3.1
The Elements
A. Ions
Ion Charges and the Periodic Table
•  The ion that a particular atom will form can be predicted from the periodic table.
–  Elements in Group 1 and 2 form 1+ and 2+ ions, respectively
–  Group 7 atoms form anions with 1- charges
–  Group 6 atoms form anions with 2- charges
Elements close to the sides of the Periodic Table gain or lose electrons to reach a
“noble gas configuration”
Section 3.1
The Elements
A. Ions
Ion Charges and the Periodic Table
Section 3.1
The Elements
Ions
What ions would be formed from the elements with the following atomic numbers? Also
what noble gas has the same number of electrons as these ions?
53
38
7
55
88
9
13
Section 3.1
The Elements
B. Compounds That Contain Ions
Ions are produced in chemical
• reactions
to form ionic compounds
•  Ions combine
Positive ions are attracted to negative
- 
ions
of ionic compounds
•  Properties
crystalline
-  Solid,
melting points
-  High
(NaCl – 801oC)
Formation of NaCl
Section 3.1
The Elements
B. Compounds That Contain Ions
•  Properties of Ionic Compounds (2)
– Can conduct electricity
•  If melted
•  If dissolved in water
Section 3.1
The Elements
B. Compounds That Contain Ions
•  Ionic compounds are electrically neutral. The pluses are
balanced by the minuses
• 
The charges on all the anions and cations in the compound must sum to zero / be in
balance.
Remember This
Section 3.1
The Elements
B. Compounds That Contain Ions
Formulas for Ionic compounds
•  Write the cation element symbol followed by the anion element symbol.
•  The number of cations and anions must be correct for their charges to sum to zero.
Section 3.1
The Elements
Ionic Compounds
What compound would be formed by the following ions?
Na+ and Cl-
K+ and F-
Fe3+ and P3-
Na+ and S2-
Mg2+ and Cl-
Mg2+ and O2-
Fe3+ and Cl-
Na+ and P3-
Al3+ and S2-
Mg2+ and N3-
What would be the symbol of the ion formed by the Nitrogen-15 isotope?