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Question
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.
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Solution
The oxidation states of lanthanoids are +2, +3, and +4. Of these, +3 is the most common state. The limited number of oxidation states is due to the large energy difference between the 4f, 5d, and 6s sub-orbitals. In contrast, actinoids show many oxidation states, such as +2, +3, +4, +5, +6, and +7, although their most common state is +3. This is because there is a small energy difference between the 5f, 6d, and 7s sub-orbitals.
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