Question

The number of d-electron in $F{e}^{2+}$ ( at. no. of Fe = 26) is not equal to that of the

• A. p - electrons in Ne (at. no. = 10)
• B. s - electrons in Mg (at. no. = 12)
• C. d - electrons in Fe
• D. p-electrons in $C{l}^{-}$ ( at. no. Cl = 17)

Answer 1

The correct option is D p-electrons in $C{l}^{-}$ ( at. no. Cl = 17)

p-electrons in $C{l}^{-}$ ( atomic no. of Cl = 17)

$C{l}^{-}\to 1s^2,2s^{2}2p^6,3s^{2}3p^6\to 12$ p electrons

$F{e}^{2+}\to 1s^2,2s^{2}2p^6,3s^{2}3p^{6}3d^6\to 6$ d electrons

In $F{e}^{2+},$ total number of d electrons $=6$ which is not equal to p electrons in $C{l}^{-}=12$