The number of d-electrons in `Fe^(2+)`(Z=26) is not equal to the number of electrons in which one of the following ?

Options

A. d-electrons in `Fe (Z = 26)`
B. p-electron in `Ne (Z = 10)`
C. s-electrons in `Mg(Z = 12)`
D. p-electrons in `Cl(Z = 17)`

Answer

D

Explanation

`Fe^(2+) : [Ar] 3d^6`
Number of d-electrons = 6`
Fe : [Ar] 3d^6 4s^2` (No. of d-electrons = 6)
`Ne : 1s^2 2s^2 2p^6` (No. of p-electrons = 6)
`Mg L 1s^2 2s^2 2p^6 3s^2` (No. of s-electrons = 6)
`Cl : 1s^2 2s^2 2p^6 3s^2 3p^5` (No. of p-electrons = 11)