Question

Which of the following has the maximum number of unpaired electrons?

• A. $M{g}^{2+}$
  
• B. $T{i}^{3+}$
  
• C. $V^{3+}$
  
• D. $F{e}^{2+}$

Answer 1

The correct option is D

$F{e}^{2+}$

$M{g}^{2+}=1s^{2}2s^{2}2p^6$ =no unpaired electron
$T{i}^{3+}=1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^1$=one unpaired electron
$V^{3+}=1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^2$ =two unpaired electron
$F{e}^{2+}=1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^6$ =four unpaired electron