Assertion : Actinoids show larger number of oxidation states than lanthanoids.
Reason : Highest oxidation state shown by lanthanoids is +4 while that of actinoids is +7.

Options

A. If both (A) and (R) are correct and (R) is the correct explanation of(A).
B. If both (A) and (R) are correct, but(R) is not the correct explanation of (A).
C. If(A) is correct, but (R) is incorrect.
D. If both (A) and (R) are incorrect.

Answer

B

Explanation

In lanthanoids, energy gap between 4f and 5d subshells is large while in case of actinoids, energy gap between 5f,6d and 7s subshell is very small