Which species has highest magnetic moment?

Options

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

Explanation

`Fe^(+)=[Ar]_(18)3d^(6) ("4 unpaired electron")rArr"Maximum magnetic moment"`
`Se=[Ar]_(18)3d^(1)4s^(2)("1 unpaired electron")`
`Ni^(+2)=[Ar]_(18)3d^(8)4s^(2)(2"unpaired electron")`
`Cu^(+)=[Ar]_(18)3d^(10)("0 unpaired electron")`