Q. Lanthanum is grouped with $f$-block elements because
A) It has partially filled $f$-orbitals
B) It has both partially filled $f$ and $d$-orbitals
C) The properties of lanthanum are very similar to the elements of $4f$-block
D) It is just before Ce in the Periodic Table
Explanation
The correct answer is Option C: The properties of lanthanum are very similar to the elements of $4f$-block.
A detailed explanation for this question is being prepared.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.