Which of the following elements is placed in the d‑block of the periodic table?

Step-by-step solution

1. Identify the atomic number of each element and its electron configuration.
2. Ytterbium has Z=70 and configuration –,[Xe]$4f^{14}6s^2$; it is a lanthanide (f‑block).
3. Yttrium has Z=39 and configuration –,[Kr]$4d^{1}5s^2$; the valence electrons occupy a d‑orbital, so it belongs to the d‑block.
4. Lutetium has Z=71 and configuration –,[Xe]$4f^{14}5d^{1}6s^2$; it is a lanthanide (f‑block).
5. Thorium has Z=90 and configuration –,[Rn]$6d^{2}7s^2$; it is an actinide (f‑block).

Concept tested: Block classification of elements

Published 16 September 2026 · How this solution was prepared and checked