Molecular Compounds
There are two basics types of compounds Ionic and molecular
Ionic Compounds

Combine positive metal ions with negative non-metal ions

Ions become ions (charged particles ) because of a need to have there outermost shell "full"

Dissolve in water to produce positive and negative ions
 When dissolved in water, conduct electricity…they are called electrolytes

There are no molecules of ionic compounds

Their bond are electrical in nature and are called ionic bonds
Molecular Compounds

Do not contain metallic elements… only non-metallic elements

The atoms of a molecule also "need" to have there outermost shell full but this is not obtained through the exchange of electrons (as is the case with ionic compounds). The atoms of a molecular compound share one or more of their outer electrons to satify the "need".

Aqueous solutions of molecular compounds do not conduct electricity

The name of these "shared pairs" is covalent bonds
See next page for examples

Examples (see p. 202)
H and
Cl
O
H and
H
H
form
Cl
H form
H
H
H
C
H
Cl
H
Cl

Writing Formulas for Molecular Compounds
We will use a carbon tetra chloride as an example. We know that his compound contains the elements carbon and chlorine. First write the symbols for the elements.
C Cl
Then put numbers above these symbols representing their carrying capacities.
4
C
1
Cl
Now criss cross the numbers
4
C
And the formula becomes
Note sometimes you have to reduce.
CCl
4
Naming Molecular Compounds
1
Cl
There are a number of molecular compounds that aren't really compounds at all. They consist of only one element where two atoms of the same element form a molecule. These are called diatomic molecules. Examples include
H
2
, Cl
2
, O
2
etc.
Many molecular compound have common names and chemical names.
Water can for instance be called water or dihydrogen oxide. Ammonia could be called nitrogen trihydride.
The chemical names of these simple compounds usually have two parts (one for each of the two elements that its made of).
 the first is the one with the higher carrying capacity
 the second often ends in "ide"
 prefixes (mono, di, tri, tetra and penta) are used to express the number of atoms of a certain element that are in the compound.

Example CF
4
N
2
O
3
Practice p. 204 # 1-6
- carbon tetrachloride
- dinitrogen trioxide
Hydrocarbons
Organic compounds are those that contain largely carbon and hydrogen.
Methane (CH
4
) is a simple example. The reason why carbon is common to so many compounds is its carrying capacity (4). Four is the most versatile carrying capacity.
Two sources of organic compounds are food (whether plant or animal) and hydrocarbons. Hydrocarbons are also called fossil fuels because they are derived from living matter (plants create organic compounds through photosynthesis). Coal, oil and natural gas are examples of hydrocarbons.
Chemists use existing organic compounds to create new substances. As an example, plastics, synthetic fibres and pharmaceuticals are made from hydrocarbons.
Commercial products are often described as either natural or synthetic.
Natural products are those that come from natural sources such as plants, animals or minerals. Examples include cotton, rubber, wood, leather, wool, metals and cement.
Synthetic products are manufactured chemically. Examples include polyester, teflon, vinyl, PVC and styrofoam (also see table on p. 209)
Polymers are a specific type of synthetic substance. they are comprised of hundreds of small molecules that are linked together to form long thin molecules. Polymers often have the prefix poly in their names.
Plastics are yet a more specific type of polymer. The polymer is made to flow at some point during its manufacture.