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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
The lanthanoide that would show colour is
  • A
    $Gd^{3+}$
  • B
    $La^{3+}$
  • C
    $Lu^{3+}$
  • ✓
    $Sm^{3+}$
✓

Answer

Correct option: D.
$Sm^{3+}$
d
$Sm^{3+}\,(4f^5) =$ yellow colour, other ions have stable electron configurations with half filled or full-filled electron configuration.

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