Which of the following has the maximum number of unpaired d-electron?

Options

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

Answer

B

Explanation

`{:(Zn^(2+),:,[Ar] 3d^(10) (0 "unpaired electrons").),(Fe^(2+),:,[Ar]3d^(6) (4 "unpaired electrons") maximum),(Ni^(3+),:,[Ar]3d^(7) (3 "unpaired electrons").),(Cu^(+),:,[Ar]3d^(10) (0 "unpaired electrons").):}`