Question

Which gaseous ion in its ground state has the greatest number of the unpaired electron?

• A. $M{n}^{3+}$
• B. $F{e}^{3+}$
• C. $C{o}^{3+}$
• D. $N{i}^{3+}$

Answer 1

Answer: (B)

$F{e}^{3+}$

The electrons are first removed from valence shell and then inner shells. If we consider this then ${Mn}^{3+},{Fe}^{3+},{Co}^{3+}$ and ${Ni}^{3+}$ have $4,5,4,3$ unpaired electrons respectively. Thus ${Fe}^{3+}$ have highest number of unpaired electrons.