Chapter 6
Chemical Bonds and Compounds
“Come Together”
By John Lennon
YouTube - John Lennon - Come
Together (The Beatles Cover)
How do these skydivers stay
together? How is this similar to the
way atoms stay together?
Objectives:
 Describe
how compounds
are made from
combinations of atoms.
 Explain how chemical
formulas represent chemical
compounds.
Section 6.1
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If we look at all the different things around us it
is easy to see that everything is not an element.
But we also know that there are just over 100
different elements and they make up millions of
different substances.
How many letters in the alphabet?
How many words are made from those 26
letters?
Atoms are held together in compounds by
chemical bonds.
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Bonds determine the properties of a
compound.
Many times the properties of compounds
are often different from the properties that
make them.
EXAMPLE
+
CALCIUM
=
CHLORINE
CALCIUM
CHLORIDE
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CALCIUM ~ A GROUP 2 ALKALINE EARTH
METAL (soft, silvery metallic solid)
CHLORINE ~ A HALOGEN is a greenish
gas very poisonous to humans
These two come together to form a
product we use to melt ice that forms on
streets and sidewalks.
It was one of the powders in the “Baggie
Blast” experiment we did a couple of
weeks ago.
In every family the number of males to
females varies. In my family there are 3
females to 2 males. Me, mom and my
sister THE GIRLS. Dad and my brother
THE BOYS. So there is a 3:2 ratio of
females to males.
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Atoms always combine in predictable
numbers
For example NH3 is ammonia. The
compound ammonia always has three
hydrogen atoms for every nitrogen atom.
Chemical formulas

Chemical formulas use chemical symbols
to represent the atoms of the elements
and their ratios.
CO 2
This chart shows the names, atoms, ratios and chemical
formulas for several chemical compounds. Notice methane
and propane are made from atoms of the same elements but
in different ratios.
Two totally different substances………
Propane in the tank on your grill and methane given off
when cows BURP!!!!!!!!!!!!!!!!!!!
Same elements, different
compounds
Which one would you want to drink?
or
Review
How
many different atoms are in C12H22O11?
12 carbon atoms + 22 hydrogen atoms 11
oxygen atoms = 45 total atoms
How
do properties of compounds compare
with the elements that make them?
Most
of the time VERY
different
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If a chemical formula has no subscripts,
for example CO (carbon monoxide)
What is the ratio of the atoms?
1 to 1
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If CO2 is carbon dioxide then is H2O
Dihydrogen monoxide? No silly teacher
H2O is water!!!!!!!!!
Section 2
objectives
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Explain how electrons are involved in
chemical bonding.
Describe what the different types of
chemical bonds are.
Determine how chemical bonds affect
structure.
What are some different
ways workers connect
materials?
Hearst Bld NYC
Look for it in a new movie
Glue
Nails
screws
Chemical bonds between atoms
involve electrons
Chemical bonds are the “glue” that holds
atoms of elements together
 Chemical bonds have an effect on the
chemical and physical properties of
compounds

Transfer Please!!!!!!!!
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When a college student needs money to
cover rent and other needs they call mom
and dad and ask them to transfer money
to their checking account. Mom or dad
calls the bank and says they want to
transfer money to little Johnny’s account.
A similar thing happens when the
atom of a metal transfers an
electron to the atom of a
nonmetal.
Ionic bond: the force of attraction
between positive and negative ions
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Example: an atom from Group 1, like
sodium (Na) forms a positive ion Na+ &
meets an atom from Group 17 (a Halogen)
chlorine (Cl) forms a negative ion Cl- the
bond forms is ionic. NaCl is table salt.
Just like opposite ends of a magnet
attract~~~~ these oppositely charged
ions attract each other.
So how we name these monsters?
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Name the positive metal element~
example sodium (Na)
Next take the name of the negative,
nonmetal element, chlorine (Cl) and give it
the ending –ide chloride
Now combine the two names making that
monster’s name sodium chloride. We just
call it salt!!!!
Let’s try some more!
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What would lithium and iodine be called?
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What about sodium and fluorine?
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And calcium and chlorine?
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Wow that is amazing YOU just learned to name
ionic compounds!!!!!!!!!!!
Salts are formed from the positive
ion of a metal and negative ion of a
nonmetal.
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Not all salts are the kind we put on our
French fries. That is NaCl.
Calcium chloride CaCl2 is put on roads and
sidewalks to melt snow and ice.
The metal ion in salts give off a
characteristic flame color as you saw in
the lady liberty fireworks site.
http://www.driveaway.com/lady_liberty/lib
erty_dl.htm
When 2 girls share the
responsibilities of being head
cheerleader what do we call them?
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They are co-head cheerleaders.
When atoms share electrons in bonding we call
this covalent bonding.
The electrons spend as much time around one
atom as they do the other atom. They zip back
and forth between atoms.
Some common substances held together by
covalent bonds are: carbon dioxide (CO2),
methane (CH4) and several elements exist
covalently bonded to themselves. H2, N2, O2, F2,
Cl2, Br2, & I2.
Polar covalent bonds
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A covalent bond in which the bonds are
shared unequally.
Water is a perfect of example of a polar
covalent bond. That is why water is a
good solvent and we take a bath in it!! It
has both positive and negative parts.
Review section 2
What
part of an atom is involved in bonding?
The electron cloud (i.e. valence electrons)
Compare
ionic and covalent bonds.
See posters
A polar covalent bond forms when?
Two atoms share electrons unequally
Section 3
Substances’ properties depend on
their bonds
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Metals have unique bonds. They slide
easily past each other giving metals their
useful qualities (ie malleable, ductile,
shiny and good conductors)
Ionic and covalent bonds give compounds
certain properties (comparison demo of
salt and PDC)
Ductile??
Bonds can make elements look
different.
copper
diamond
fragment
graphite fragment
Review
What are the three forms of carbon?
Diamond, graphite, and
fullerene
Metallic bonds make many metals good what?
Good conductors of
electricity