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-electrons in Ne (Z=10)
C. s-electrons in Mg(Z=12)
D. p-electrons in Cl(Z=17)

Answer

D

Explanation

The electronic configurations of the atoms involved are :
(a) Ff(Z=26) , `[Ar]^(18)3d^(6) 4s^(2) " " ` (d electrons = 6)
(b) Ne(Z=10) , `1s^(2)2s^(2)2p^(6) " "` (p electrons = 6)
(c) (Mg=12) , `1s^(2)2s^(2)2p^(6)3s^(2) " "` (s electrons =6)
(d) (Cl=17) , `1s^(2) 2s^(2)2p^(6) 3s^(2)3p^(5) " "` (p electrons =11)
`Fe^(2+)` ion has six d electrons and these are not equal to p-electron (11) in chlorine (Cl) atom.