The chemistry of the actinoid elements is not so smooth as that of the lanthanoid. Justify this statement by giving some example from the oxidation state of these elements

Explanation

The lanthanoids mostly exhibit +3 oxidation states in their compounds. Actinoid elements also normally show +3 oxidation states. But in their cases, 5f,6d and 7s energy levels are comparable and have very small energy difference in them. As a result, they can exhibit a number of oxidation states. For example.,
Neptunium (Np): +3,+4,+5,+6,+7
Plutonium (Pu) : +3,+4,+5,+6,+7
Americium (Am): +3,+4,+5,+6.