What's in a name? Quite a bit! Even the type of name can tell you something because different types of names are associated with different types of compounds.

Prefix Names

Prefix names are used primarily with covalent compounds. The name tells which elements are present. The most electronegative element is last in the name and has an "-ide" ending. The prefixes tell how many of each atom are in the formula. The prefixes used are "mon-" or "mono-" for one, "di-" for two, "tri- " for three, "tetra-" for four, "penta-" for five, "hexa-" for six, "hepta-" for seven, "octa-" for eight, "nona-" for nine, and "deca-" for ten. The absence of a prefix generally means there is one of those atoms in the formula if it is a prefix name. The "a-" and "o-" endings of the prefixes are generally dropped when attached to "oxide."

Stock Names

Stock names can be used for covalent and ionic compounds when the first element in the name can have more than one charge or oxidation state. They are used mostly for ionic compounds containing transition metals. The charge or oxidation state of the first element is shown in parentheses using Roman numerals at the end of the name of that element. 

Oxidation States

Oxidation state is very much like the charge on an ion but it can apply to any element whether it is metal or nonmetal, ionic or covalent.  

Latin Names

Latin names are the old names used for both ionic and covalent compounds to indicate high and low oxidation states of the first element in the name. These names only work well if there are only two oxidation states for the element or at least only two common oxidation states.  

Simple Names

Simple names are used primarily for ionic compounds but also for several covalent compounds. Simple names are used when only one possible combination of the elements exists. These names are like Stock names without the Roman numerals because they are not needed.

Hydrates

Sometimes molecules of water are incorporated into the crystals of ionic compounds in a very systematic fashion. When this happens, the number of water molecules are included in both the name and the formula.