a. The names of the elemental anions are made by adding the --ide suffix to the
root of the element's name. Thus anions formed by chlorine (Cl-1) are called chloride
ion; anions formed by oxygen (O-2) are called oxide ion.
(a) Br -1 is called ______________________ion.
(b) S -2 is called ______________________ ion.
H -1 is called ion.
(d) N -3 is called ion.
b. The most common type of anionic radicals consists of a central atom
covalently bonded to a number of atoms of oxygen. Monovalent anionic radicals
(Valence = -1) normally contain three oxygen atoms; radicals with negative valences
greater than one normally contain four oxygen atoms. The names for these normal
types of radicals are formed from the root for the name of the central atom plus the
suffix -ate. Thus, ClO3 -1 is named chlorate and SO4 -2 is named sulfate. It is important
to note that these generalizations have exceptions. The best way to remember the
names and formulas for the radicals is to memorize the common ones. Most of these
are listed in this subcourse.
(1) Sometimes a central atom may be bonded to a different number of
oxygen atoms than normal; in other words, a series of radicals may be formed with the
same central atom. Different suffixes and prefixes are used to name these different
radicals. When there is one less oxygen atom than normal, the suffix -ite is used. The
name for ClO2 -1 is chlorite; SO3 -2 is called sulfite.
(2) Occasionally, there are other radicals in a series. This is especially true
of the halides (fluoride, chloride, bromide, and iodide ions). If there are two less oxygen
atoms than usual, the -ite suffix is used with the prefix hypo-. For example, ClO-1 is
called hypochlorite. If there is one more oxygen atom than normal, the -ate suffix is
used in combination with the prefix per-, so ClO4 -1 is named perchlorate.