The configuration `[Ar]3d^(5)4s^(1)` in the first excited states exists for

Options

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

Answer

A, B

Explanation

`Fe^(2+)` : Ground state = `3d^6`
`" "` Excited state `= 3d^5 4s^1`
b) `Co^(3+)`: Ground state = `3d^6`
`" "` Excited state `=3d^5 4s^1`
c) `Mn^(+) : ` Ground state =`3d^5`
`" "` Excited state `= 3d^5 4s^1`
d) Cr : Ground state `=3d^5 4s^1`
`" "`Excited state : Excited state `=3d^5 4p^1`