Unit 3
The Periodic Table &
Chemical Bonding
The elements of the periodic table can be
divided into three main categories:
Metals, Non-Metals, and
Metalloids.
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Properties of Metals
 Found on the left side of the Periodic
Table
 Metals are
 good conductors of heat and electricity.
 shiny.
 ductile (can be stretched into thin
wires).
 malleable (can be pounded into thin
sheets).
 A chemical property of metal is its
reaction with water which results in
rust/corrosion.
Properties of Non-Metals
 Found on the right side
of the Periodic Table
 Non-metals are
 poor conductors of heat
and electricity.
 not ductile or malleable.
 Solid non-metals are
brittle and break easily.
 They are dull.
 Many non-metals are
gases.
Sulfur
Properties of Metalloids
 Located between Metals
Silicon
and Non-Metals on the PT
 Metalloids (metal-like) have
properties of both metals
and non-metals.
 They are
 solids that can be shiny or
dull.
 ductile and malleable.
 conduct heat and electricity
better than non-metals but
not as well as metals.
Periods
 Each horizontal row of elements is
called a period.

The elements in a period are not
alike in properties.
Each element in the same period
 has the same number of energy
levels (electron shells)
 The first element in a period is
always an extremelyactive solid.
The last element in a period, is
always an inactive gas.
 As you travel right across a period,
you increase the number of protons
in the nucleus by 1
Families

Columns of elementsare called
groups or families.

Elements in each family have
very similar properties.
All elements in a family have
 the same number of valence
electrons.
As you move down a family,
 each new element has an extra
energy level (electron shell)
Hydrogen
 The hydrogen square sits
atop Family IA, but it is
not a member of that
family.
 Hydrogen is in a class of its
own. It is NOT in the next
family.
 It’s a gas at room temperature.
 It has one proton and one electron in its one and
only energy level.
 Hydrogen only needs 2 electrons to fill up its valence
shell.
Periodic Table Family Names
Valence Electrons
Each family has a set number of valence electrons.
This is why each element in one family reacts similarly.
 1 = Alkali Metals
 2 = Alkali Earth Metals
 3 = Boron Family
 4 = Carbon Family
 5 = Nitrogen Family
 6 = Oxygen Family
 7 = Halogen Family
 8 = Nobel Gas Family
 Variable = Transition Metals
Each family also has a specific OXIDATION NUMBER
(More on Oxidation Numbers later)
Notes on Specific Families
Group 1: Alkali Metals
 Hydrogen is not a member, it is a
non-metal
 1 electron in the outer shell
 Often react with Halogen Family
 Very reactive, esp. with water
Group 2: Alkaline Earth Metals
 2 electrons in the outer shell
 Often reactive with Oxygen Family

(less reactive than Alkali metals though)
Notes on Specific Families
Group 3-12: Transition Metals (That block in the middle)
 Valence electrons (and thus Oxidation Numbers) can vary
For instance Cu can have 1, 2, 3, or 4 valence electrons depending on the
version of Cu
Good conductors of heat and electricity.
 Used for wiring, tools, jewelry, decorative metalwork, etc…
Notes on Specific Families
Group 13: Boron Family
 Most are metals  Boron is a
metalloid
Group 14 & 15:
Carbon Family AND Nitrogen Family
 Contains metals, metalloids,
and a non-metal
 Contains metals, metalloids,
and non-metals
Families
Notes on Specific Families
Group 16: Oxygen Family
 Contains metals, metalloids, and
non-metals
 Reactive: Generally with Alkaline
Earth Metals
Group 17: Halogen Gases
 All are non-metals
 Very reactive
 Often bonded with elements from Group 1
Notes on Specific Families
Group 18: Noble Gas Family
 Exist as gases  All are non-metals
 Not reactive with other elements because their valence
shell is full
 8 electrons in the outer shell = Full
 Helium (He) has only 2 electrons in the outer shell to be full
Rare Earth
Metals
Lanthanide Series
Actinide Series
 Some are Radioactive
 The rare earths are silver, silvery-white, or
gray metals.
 Conduct electricity
Actinides are found primarily in applications where
their radioactivity can be used to power devices such as
cardiac pacemakers.
Recap!
“Happy” Elements
 All elements want to
be “happy”
 An atom wants a
stable outer energy
level to make them
“happy”
How do they become happy?
 Atoms will gain or lose
electrons in order to
become stable.
 Usually the most stable
configuration involves
having 8 valence e 8 electrons = full octet
Octet Rule
 Atoms will form bonds with other atoms
in order to have eight valence electrons.
 Can share or transfer electrons with other
elements
 Elements will not just lose or gain electrons. They
will give to another element or take from another
Oxidation Numbers
 The oxidation
number indicates
how many
electrons are going
to be lost or gained
during bonding.
 Range from -4 to +4
Predicting Oxidation Numbers
1. First, determine how many valence electrons
the neutral atom has.
2. Determine if the atom will lose or gain
electrons.
 Ask yourself, which would be faster?
A) Losing down to zero
 B) Gaining up to eight

3.Count the number of electrons gained or lost.
If you lose electrons, the charge will be (+)
If you gain extra electrons, the charge will be (-)
Practice
 What would the oxidation number be for the following
atoms?
 A) Lithium
1+
B) Sulfur
2-
 C) Aluminum
3+
D) Iodine
1-
 E) Phosphorous 3 G) Neon
0
F) Carbon 4±
Oxidation #s on the PT
Chemical Stability
 Knowing this information about oxidation
numbers, which elements are the most
chemically stable elements?
Noble gases
- Are the most stable
elements
- They have 8 valence
electrons and don’t
want to gain or lose
any electrons
Chemical Bonds
 Only involve ELECTRONS
 The nucleus does not matter here
 Elements will not just lose or gain electrons. They
will give to another element or take from another
element
 There will always be AT LEAST 2 atoms involved in
this process.
 Binary Compound = Compound with ONLY 2
elements in it
 NaCl, CaCl2, K2S, etc..
Types of Chemical Bonds
 There are 3 different ways that two (or more)
atoms can interact or BOND
 This bonding will always end in a new
COMPOUND with new chemical properties
 3 types of bonds:
 Ionic
 Covalent
 Metallic
Ionic Bonds
 Formed when one atom gains an electron
and another atom loses an electron.
 One atom transfers their electrons to the
other atom.
Ionic Bonds
 Formed when one
atom gains an
electron and
another atom
loses an electrons.
 One atom
transfers their
electrons to the
other atom.
More on Ionic Bonds
 Occurs between a
metal and a nonmetal.
 Two oppositely
charged ions.
 The product is a neutral
compound – and the
oxidation #’s add to
zero!
 If they don’t add to
zero, you did it wrong.
Properties of Ionic Compounds
 Stronger bonds
 High melting points
 Conduct electricity when in solution or in
a molten state
 Generally dissolve in water
 Generally crystalline solid at room temp.
Drawing Ionic Bonds
 Lets use NaCl (a metal and a nonmetal)
 1st – Determine the oxidation numbers
Na = 1+
Cl = 1 2nd – Draw the Lewis Structure for each atom
 3rd – Draw the electron(s) being transferred in
the proper direction
 DOUBLE CHECK:
Does each atom have
a full valence orbital?
Exploring Ionic Bonds
 Remember that when atoms bond, they form
new compounds with different properties.
Types of Chemical Bonds
 There are 3 different ways that two (or more)
atoms can interact or BOND
 This bonding will always end in a new
COMPOUND with new chemical properties
 3 types of bonds:
 Ionic
 Covalent
 Metallic
Covalent Bonds
 Occur between two or more nonmetals.
 Formed when two atoms share electrons
with one another.
 Can be between two different atoms, or
between two atoms of the same element
 Also called Molecular compounds
 aka MOLECULE
Properties of Covalent Bonds
 Weaker bonds
 Low melting and boiling points
 Do NOT conduct electricity when in
solution
 Generally don’t dissolve in water.
 Generally gases or liquids at room
temperature
Drawing Covalent Bonds
 Lets use HCl (2 non-metals)
 1st – Draw the Lewis Structure for each atom
 2nd – Draw the electron(s) being shared
 3rd – Draw each covalent bond as a line
between the two atoms
 DOUBLE CHECK:
Does each atom have
a full valence orbital?
PRACTICE COVALENT BONDS
H2O
CH4
CO2
Diatomic Molecules
Formed between two atoms of the
same element covalently bonded
together. They cannot exist as lone
atoms and must bond to something.
Called Molecules
 H2 O2 N2 I2 Br2 Cl2 F2
 forms a seven on the periodic
table
How do you know which type of bond is formed?
IONIC
- Metal and Nonmetal
- Transfer Electrons
COVALENT
- Two Non Metals
- Share Electrons
Bond Types (cont’d)
 Metallic—Between two metals
 All metals want to give away electrons
because they have + oxidation numbers
 Don’t transfer electrons specifically
 Allow electrons to f low from one atom
to another. Can pass between many
atoms.
Writing and Naming
Chemical Formulas
Ionic vs. Covalent