Give examples.
a).Positive radicals
b).Basic radicals
c).Composite radicals
d).Metals with variable valency
e).Bivalent acidic radicals
f).Trivalent basic radicals

Hint: We have to remember that the radicals are created by gaining or losing the electrons. And the radicals are divided into many types according to the losing or gaining of electrons ions from the parent compound like positive radicals, negative radicals, acidic radicals, basic radicals, etc. For example, the basic radicals are formed from a base and they are the chemical species with positively charged.

Complete answer:
Positive radicals: The positive radicals are formed by the loss of a group of atoms which acquire a positive charge and this type of radical is known as positive radicals. Some examples of positive radicals is\[N{a^ + },A{g^ + },C{r^{3 + }},N{i^{2 + }},F{e^{2 + }}\], etc.
Negative radicals: The negative radicals are formed by the gaining of a group of atoms and it attains negative charge and it is known as negative radicals. For example, \[C{l^ - },NO_3^ - ,{I^ - },B{r^ - }\], etc.
Composite radicals: The composite radicals are the group of atoms having different types of elements and it contains either negative or positive charge. The composite radical always behaves like a single atom. And the example is, methane, acetyl and methyl.
Metals with variable valency: There is a formation of positively charged metal ions by the donation of electrons from their valence shell and that element occurs more than one valency which means variable valency. For example, mercury, tin, copper and iron etc, exhibit the variable valency.
Bivalent acidic radicals: The bivalent acidic radicals are formed by the removal of two hydrogen from the acid. And the example is, \[{S^{2 - }},{O^{2 - }},S{e^{2 - }}\]
Trivalent basic radicals: The trivalent basic radicals are cations having the valency three and such type of cation is known as trivalent basic radicals. For example, \[F{e^{3 + }},C{r^{3 + }},B{i^{3 + }},A{l^{3 + }}\], etc.

Note:
We need to know that the radicals are divided into different types on the bases of gaining and losing electrons or hydrogens. In the case of acidic radicals, it is formed by the removal of hydrogen ions and the basic radicals are formed by the removal of hydroxide ions. The \[{H_2}SO_4^ - \]ion is formed by the removal of one hydrogen ion from the sulphuric acid.