Question

Which of the following metals has most number of unpaired electrons?

• A. Mn
• B. Fe
• C. Sc
• D. V

Answer 1

The correct option is A Mn

The ground state electronic configuration of $Mn$
$=\left[Ar\right]4s^{2}3d^5$
So number of unpaired electrons in $Mn$ = 5
The ground state electronic configuration of $Fe$
$=\left[Ar\right]4s^{2}3d^6$
So number of unpaired electrons in $Fe$ = 4
The ground state electronic configuration of $Sc$
$=\left[Ar\right]4s^{2}3d^1$
So number of unpaired electrons in $Sc$ = 1
The ground state electronic configuration of $V$
$=\left[Ar\right]4s^{2}3d^3$
So number of unpaired electrons in $V$ = 3

Thus, $Mn$ has the most number of unpaired electrons.