Which of the following has more number of unpaired d-electrons ?

Options

A. `Zn^(+)`
B. `Fe^(2+)`
C. `Ni^(3+)`
D. `Cu^(+)`

Answer

B

Explanation

`Zn^(+) : 1s^(2) 2s^(2)2p^(6) 3s^(2) 3p^(6) 4s^(1) 3d^(10)`
`Fe^(2+) : 1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(6)`
`Ni^(3+) : 1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(7)`
`Cu^(+) : 1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(10)`