Nomenclature

Binary compounds are named by following a set of rules.

• For compounds containing both a metal and a nonmetal, the metal is always named first. The nonmetal is named from the root element name.

• If the metal ion can have more than one charge (Type II), a Roman numeral is used to specify the charge

• For binary compounds containing only nonmetals (Type III), prefixes are used to specify the numbers of atoms present.Polyatomic ions are charged entities composed of several atoms bound together. They have special names and must be memorized.

Naming ionic compounds containing polyatomic ions follows rules similar to those for naming binary compounds.