Question

How many unpaired electrons are present in ${Ni}^{2+}$?

• A. $0$
• B. $2$
• C. $4$
• D. None of the above

Answer 1

The correct option is B $2$

$N{i}^{2+}$ looses electrons from the 4s orbital and has 8 electrons in the 3d orbital resulting in 2 unpaired electrons.

Atomic number of $Ni$ is $28$.

$Ni:\left[Ar\right]{3d}^8{4s}^2$

${Ni}^2:\left[Ar\right]{3d}^8$

$\uparrow \downarrow$

$\uparrow \downarrow$

$\uparrow \downarrow$

$\uparrow$

$\uparrow$

There are two unpaired electrons.

Hence,option B is correct.