The cationic species (usually metals) are usually named simply as the element, e.g., NaCl:
sodium chloride, CaF 2 : calcium fluoride. For elements that can form more than one positive
ion, the charge is indicated by a Roman numeral in parentheses following the name of the
element.
Fe2+ Iron (II) Cu+ Copper (I)
Fe3+ Iron (III) Cu2+ Copper (II)
1.
An older but still commonly used method is to add the endings –ous or –ic to the root of the
Latin name of the element, to represent the ions with lesser or greater charge, respectively.
Fe2+ Ferrous Cu+ Cuprous
Fe3+ Ferric Cu2+ Cupric
2.
Monatomic anions (single-atom anions) are named by dropping the ending of the name of the
element and adding –ide, as in the examples of sodium chloride and calcium fluoride above.
Also:
H– Hydride
S2– Sulfide
N3– Nitride
O2– Oxide
P3– Phosphide
3.
Many polyatomic anions contain oxygen and are called oxyanions. When an element forms
two oxyanions, the name of the one with less oxygen ends in –ite and the one with more
oxygen ends in –ate.
NO 2 – Nitrite SO 3 2– Sulfite
NO 3 – Nitrate SO 4 2– Sulfate
4.
When the series of oxyanions contains four oxyanions, prefixes are also used. Hypo– and per–
are used to indicate less oxygen and more oxygen, respectively. (Note that these prefixes are
used only when there are more than two possibilities for the oxyanion.)
ClO– Hypochlorite
5.
