The pair in which both actinides show +3 oxidation state only is
(a)Ac and Lr
(b)Ac and No
(c)Cm and Bk
(d)Cm and Lr
Answer
Answer (as printed): A
Explanation
Ac shows only the +3 oxidation state because it achieves the nearest noble-gas configuration of Rn. Lr shows only the +3 oxidation state because it achieves the fully filled $[\mathrm{Rn}]5f^{14}$ configuration.