Question

$N{i}^{2+}ion(Z=28)$ contains _______ unpaired electrons.

• A. 1
• B. 2
• C. 3
• D. 5

Answer 1

The correct option is B 2

The electronic configuration of Ni is
${}_{28}Ni=1s^2,2s^{2}2p^6,3s^{2}3p^{6}4s^2,3d^8$

$N{i}^{2+}=1s^2,2s^{2}2p^6,3s^{2}3p^6,3d^8$


3d subshell has 2 umpaired eletrons. Hence option (b) is the correct answer.