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Which of the following elements is a d‑block element? A) Ytterbium (Yb) B) Yttrium (Y) C) Lutetium (Lu) D) Thorium (Th)

easy MCQ 1 mark Class 12 · Chemistry · d- and f-Block Elements
  1. A) Ytterbium (Yb)
  2. B) Yttrium (Y)
  3. C) Lutetium (Lu)
  4. D) Thorium (Th)
Answer
B) Yttrium (Y)

The correct answer is B) Yttrium (Y) — Thus only Yttrium is a d‑block element.

Step-by-step solution

  1. Identify the valence subshell of each element.
  2. Yttrium has 3d¹4s² electrons – the 3d subshell is part of the d‑block.
  3. Ytterbium (4f¹⁴6s²) and Lutetium (4f¹⁴5d¹6s²) belong to the f‑block because the 4f subshell is being filled.
  4. Thorium (6d²7s²) is an actinide and is also considered part of the f‑block.
  5. Thus only Yttrium is a d‑block element.
Common mistake: Choosing Yb or Lu as d‑block

Concept tested: Identify d‑block element

Published · How this solution was prepared and checked

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