Question

The first four ionization energies for an imaginary element, Xz, are E1 = 102 kcal, E2 = 186 kcal, E3 = 4021 kcal, and E4 = 4862 kcal. The most probable number of valence electrons as indicated by this ionization data is:

Answer 1

2 electron because there is a sharp rise between the 2nd and 3rd ionisation energies