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

Answer

Lanthanoids show limited number of oxidation state, Viz,+2,+3 and +4 (Out of which +3 is most common). This is because of large gap between 4f, 5d and 6s subshells. The dominant oxidation state of actinoids is also +3 but they show a number of other oxidation state also ,e.g., uranium+4 and +7 etc. this is due to small energy difference between `5f` 6d and 7s subshells of the actinoids.