Assertion (A) Actinoids form relatively less stable complexes as compared to lanthanoids.
Reason (R ) Actinoids can utilise their 5f orbitals alongwith 6d orbitals in bonding but lanthanoids do not use their 4f orbital for bonding.

Options

A. Both assertion and reason are true, and reason is the correct explanation of the assertion.
B. Both assertion and reason are true but reason is not the correct explanation of the assertion.
C. Assertion is not true but reason is true.
D. Both assertion and reason are false

Answer

C

Explanation

(c) Correct reason. Actinoids form relatively more stable complexes as compared to lanthanoids.