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4. d and f- block elements — Chemistry STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceChemistry4. d and f- block elements1 Mark
MCQ
Zinc and mercury do not show variable valency like $d-$ block elements because
  • A
    They are soft
  • ✓
    Their $d- $ shells are complete
  • C
    They have only two electrons in the outermost subshell
  • D
    Their $d-$ shells are incomplete
✓

Answer

Correct option: B.
Their $d- $ shells are complete
b
(b)$_{30}Zn$ and $_{80}Hg$ have their $d$  orbitals completely filled so they do not show any variable valency.

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