The correct statements among the following are, A. Mo(VI) and W(VI) are less stable than Cr(VI) . B. Ce⁴⁺ and Tb⁴⁺ are oxidant while Eu²⁺ and Yb²⁺ are reductant. C. Cm and Am have seven unpaired electrons. D. Actinoid contraction is greater from element to element than lanthanoid contraction. Choose the correct answer from the options given below:

Step-by-step solution

In d-block elements, the stability of higher oxidation states increases down a group. Therefore, Mo(VI) and W(VI) are more stable than Cr(VI) . Statement A is incorrect. The most stable oxidation state for lanthanoids is +3 . Ions like Ce⁴⁺ and Tb⁴⁺ tend to gain an electron to achieve the +3 state, acting as oxidants. Conversely, Eu²⁺ and Yb²⁺ tend to lose an electron to achieve the +3 state, acting as reductants. Statement B is correct. The electronic configuration of Am is [Rn] 5f⁷ 7s² , which has 7 unpaired elec