Which electronic configuration of an element has abnormally high difference between second and third ionization energy?

Options

A. `1s^(2),2s^(2),2p^(6),3s^(1)`
B. `1s^(2),2s^(2),2p^(6),3s^(1)3p^(1)`
C. `1s^(2),2s^(2),2p^(6),3s^(2)3p^(2)`
D. `1s^(2),2s^(2),2p^(6),3s^(2)`

Answer

D

Explanation

Abnormally high difference between 2nd and 3rd ionization energy means that the elements has two valence electrons, i.e., configuration (d)