Question

The number of unpaired electrons in cobalt atom is (atomic number of Co = 27).

• A. 2
• B. 3
• C. 4
• D. 1

Answer 1

Answer: (B)

3

Answer 2

Electronic configuration of $27Co$-

$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{7}4s^{2}$,

hence unpaired $e^{-}$= 3