Which one of the following pairs of ions have the same electronic configuration?

Options

A. `Cr^(3+), Fe^(3+)`
B. `Fe^(3+), Mn^(2+)`
C. `Fe^(3+), Co^(3+)`
D. `Sc^(3+), Cr^(3+)`

Answer

B

Explanation

`Sc(Z = 21):[Ar]3d^(1)4s^(2)`
`Cr (Z = 24): [Ar]3d^(5)4s^(1)`
`Mn (Z = 25):[Ar]3d^(5)4s^(2)`
`Fe(Z = 26):[Ar]3d^(6)4s^(2)`
`Co(Z = 27):[Ar]3d^(7)4s^(2)`
Thus, `Fe^(3+) ([AR]3d^(5))` and `Mn^(2+)[(Ar]3d^(5))` have the same electronic configuration.