Question

The electron configurations of five different elements are shown below. which of these elements is expected to have the largest second ionization energy (ie2 )?*

Answer 1

Missing question:

(a) 1s2 2s2 2p6 3s1
(b) 1s2 2s2 2p6 3s2
(c) 1s2 2s2 2p6 3s2 3p1

(d) 1s2 2s2 2p6 3s2 3p4

(e) 1s2 2s2 2p6 3s2 3p5

Answer is: a) 1s²2s²2p⁶3s¹ (sodium).

Sodium have the largest second ionization energy, because when he lost one electron(first ionization energy), he have stable electron configuration of noble gas neon (1s²2s²2p⁶), so sodium do not need to lost second electron, because he will have unstable electron configuration.