| When atoms bond together to form molecules, they are not balancing charges (which is the
case for ionic compounds). Therefore, at this point in the course,
there is no way to predict how many of each atom will bond
together. In addition, there are several different ways that two
different atoms may bond together (e.g., carbon and oxygen may bond in a
2:1 or 1:1 ratio - CO2 and CO). This is why we need a
way to tell how many of each atom are in the molecule.
Rule 1: Use number prefixes to tell how many of each
type of atom is in the molecule.
| 1 = mono |
|
6 = hexa |
| 2 = di |
|
7 = hepta |
| 3 = tri |
|
8 = octa |
| 4 = tetra |
|
9 = nona |
| 5 = penta |
|
10 = deca |
Exception: We do not use the
prefix mono for the first atom in the name, only the second.
Note: When the second element
is oxygen, usually the "a" at the end of the prefix is
eliminated (tetroxide).
Rule 2: The ending of the name of the second atom is
changed to "ide".
|
