Question

The electronic configuration of an element with the largest difference between the $1^{st}$ and $2^{nd}$ ionization energies is

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

Large difference between $1^{st}$ and $2^{nd}$ I.E. happens when an abnormal jump happens in the values of respective I.E. s,
and, abnormal jump in I.E. is normally observed when we break into an inner shell (having fully-filled inert configuration)
Hence for metal m,
$m\leftarrow 1s^{2}2s^{2}2p^{6}3s^1\to I.E_1{m}^{+}\to 1s^2\underset{}{2s^{2}2p^6}\to I.E_2\left(Electrontoberemovedfrom2p\right)\text{fully-filled inert configuration}$

Hence $I.E_2>>I.E_1$