Most of the radioactive elements are in

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

Assertion A : Size of ${\mathrm{Bk}}^{3+}$ ion is less than ${\mathrm{Np}}^{3+}$ ion.

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

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

Give two reasons.

The chemistry of actinoids is more complicated than Lanthanoids.

How will you account for the following?

Actinoids exhibit more number of oxidation states than lanthanoids.

Give reason for actinides show irregularities in their electronic configuration.

Give reason: Actinoid contraction is greater from element to element than lanthanoid contraction.