Q. How many unpaired electrons are present in the central metal ion of $\left\lbrack CoCl_{4} \right\rbrack^{2 -}?$
A) 2
B) 3
C) 4
D) 5
Explanation
(b)
$\ _{27}Co \longrightarrow \lbrack Ar\rbrack 3d^{7}4s^{2}$
$Co^{2 +} \longrightarrow 3d^{7}4s^{0}$
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Number of unpaired electrons = 3
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.