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 C1 (Z =17)

Answer

D

Explanation

(a) E.C of Fe (Z=26)
`= 1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(6) 4s^(2)`
`:. `E.C. of `Fe^(2+) = 1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(6)`
It has six p- electrons.
( c) E.C. of Mg (Z= 12) = `1s^(2) 2s^(2) 2p^(6) 3s^(2)`
It has eleven ( 6+5) p-electrons .
Now C1 has eleven p-elements but `Fe^(2+)` has six d- electrons. Therefore option (d) is correct.