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

Options

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

Answer

B

Explanation

`Zn^(+)` (at no. of =26)`=1s^(2),2s^(2)2p^(6),3s^(2)3p^(6)3d^(6)`

`N^(3+)("at no".=7) = 1s^(2), 2s^(2)2p^(6), 3s^(2)3p^(6)3d^(6)`
`N^(3+)("at no.="7) = 1s^(2), 2s^(2), 2p^(0)` ("no unpaired electrons")
`Cu^(+)(at no.=29) =1s^(2),2s^(2)2p^(6),3s^(2)3d^(10)` ("no unpaired electrons")
So, the maximum number of unpaired electrons are present in `Fe^(2+)`.