NEET UG 2021 · Chemistry · Question 56
NEET 2021 Chemistry, question 56
Question 56 of the NEET 2021 paper (code O1) is a Chemistry question from The d- and f-Block Elements. Its idea, Lanthanoid Contraction, was asked only this once in NEET 2017–2026. The NTA final answer key gives option 1.
Updated 2026-10-08
Q56 · Chemistry
Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of :
- 1lanthanoid contractionOfficial answer
- 2having similar chemical properties
- 3belonging to same group
- 4diagonal relationship
Official answer: option 1 · NTA final answer key
Same idea
The only question on Lanthanoid Contraction
No other NEET paper from 2017–2026 tested this exact idea.
Lanthanoid Contraction: every question and how it was framed
The chapter
The d- and f-Block Elements in ten years of NEET
21 questions from 2017–2026, asked in 10 of 10 papers, about 2.0 a paper. d- and f-Block Elements alone had 21.