Assertion: Actinoids show greater number of oxidation states than lanthanoids. Reason: Actinoids are radioactive.

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 (A) is incorrect but (R) is correct.

Answer

b

Explanation

Correct R: in actinoids, the 5f, 6d and 7s subshells are close in energy whereas in lanthanoids 4f, 5d and 6s subshells have larger energy gaps.