Actinides exhibit larger oxidation states than lanthanides, because of the very small energy gap between 5f, 6d and 7s subshells. Thus, the outermost electrons get easily excited to the higher energy levels, giving variable oxidation states.

The important characteristics of transition metals are:

(i) All transition elements are metallic in nature, e.g., all are metals.

(ii) These metals exhibit variable oxidation states.

(iii) Transition metal atoms or ions generally form the complexes with neutral, negative and positive ligands.

(iv) Compounds of transition metals are usually coloured.

(v) The compounds of these metals are usually paramagnetic in nature.

(vi) Transition metals and their compounds act as good catalysts, i.e., they...