b. The second method for naming metallic cations uses the name of the element
followed by a roman numeral in parentheses to indicate the valence. For example, Cu+1
is written as copper (I) and Cu+2 is written as copper (II). Remember, these methods for
specifying valence need be used only when there is more than one valence possible.
(a) Fe+2 is written
(b) Fe+3 is written
Mg+2 is wrjtten
(d) Hg+1 is written
(e) Ag+1 is written
Pb+4 is written
Iron (II) (ferrous).
Iron (III) (ferric).
Mercury (I) (mercurous).
Lead (IV) (plumbic).
1-12. NAMING ANIONS
There are generally two types of anions. Many anions are elemental; that is
they are made of only one atom of one element. Others are composed of groups of
atoms of one or more elements that pass through a reaction unchanged in most cases.
This latter group of anions is called radicals. We will concern ourselves first with the
naming of elemental or monatomic anions.