The chemistry of the actinoid elements is not so smooth as that of the lanthanoids. Justify this statement by giving some examples from the oxidation state of these elements.
Apart from +3 oxidation state, lanthanoids show +2 and +4 oxidation states due to large energy gap between 4f and 5d subshells. Whereas actinoids show large number of oxidation states due to small energy gap between 5f and 6d subshells. For example, uranium (Z = 92) shows +3, +4, +5 and +6 oxidation states and neptunium (Z=94) shows +3,+4,+5,+6 and +7 oxidation states due to small energy gaps between 5f and 6d orbitals.
