Compound Naming

Compound naming, in chemistry, is usually done with binomial nomenclature (two-part names).

Metal and Nonmetal Combination:

When naming a metal and nonmetal compound, the first part of the name is simply the name of the metal. The second part of the name is the name of the polyatomic ion that follows, or ones of the "ides." If the nonmetal is oxygen, the second part of the name is oxide. Nitrogen = nitride, sulfur = sulfide, fluorine = fluoride, and so on...

If you're working with a metal that has more than one valence, the valence should be specified as a Roman numeral after directly after the metal it corresponds to.

For example:
NaF = sodium fluoride
CrCl₃ = chromium (III) chloride
AgNO₃ = silver nitrate
KMnO₄ = potassium permanganate

Nonmetal and Nonmetal Combination:

Combining two nonmetals is very different, so disregard the rules above, minus the part about the "ides." Above, the number of atoms per element doesn't matter when naming, but it's an essential part of naming here. The first part (element with the positive valence) of the name needs a numeric prefix if there's more than one atom, and the second part (negative valence) needs a prefix in all cases.

Here are the numbers and their prefixes:

1. Mono
2. Di
3. Tri
4. Tetra
5. Penta
6. Hexa
7. Hepta
8. Octa

Examples:
CO = carbon monoxide
SF₆ = sulfur hexafluoride
NO₂ = nitrogen dioxide
P₂O₅ = diphosphorous pentoxide

Also see: Acid Naming.