Given below are two statement : one is labelled as Assertion A and the other is labelled as Reason R :

Assertion A : Size of Bk³⁺ ion is less than Np³⁺ ion.

Reason R : The above is a consequence of the lanthanoid contraction.

In the light of the above statements, choose the correct answer from the options given below :

Which one of the following lanthanoids does not form MO₂? [M is lanthanoid metal]

Given below are two statements :

Statement I : CeO₂ can be used for oxidation of aldehydes and ketones.

Statement II : Aqueous solution of EuSO₄ is a strong reducing agent.

In the light of the above statements, choose the correct answer from the options given below :

In which of the following pairs, the outer most electronic configuration will be the same?