Question

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

(a) 1s², 2s²,2p⁶,3s¹

(b) 1s², 2s², 2p⁶, 3s¹3p¹

(c) 1s², 2s², 2p⁶, 3s²3p²

(d) 1s², 2s², 2p⁶, 3s²

Answer 1

The correct option is : (d) 1s², 2s², 2p⁶, 3s²

Explanation:

Abnormally high difference between 2^nd and 3^rd ionisation energy means that the element has two valence electrons, which is a case in configuration (d).