Grade 12 Chemistry ~ Ionization energy

Question

The following data concerns the ionization energies of a given atom:

EI1 = 738 kJ / mol; EI2 = 1451 kJ / mol; EI3 = 7733 kJ / mol. Predict the configuration of the valence electrons of this atom and explain your reasoning.

Answer 1

There is a large jump in ionization energy from IE2 to IE3 suggesting IE3 is for removing a non valence shell electron. So we can focus on IE1 and IE2 suggesting 2 valence electrons thus belonging probably to group 2. The configuration of the valence electrons s2 electrons, if that's what they mean by configuration.