Table shows all four successive ionisation energies of X. Deduce the valence electrons, group no. & valence electronic configuration from the data of successive ionisation energies
IE 3 to IE 2 have the highest ratio @ drastic increase in ionisation energy from IE 2 to IE 3
The 3 rd electron is removed from the inner shell which has a stable noble gas electron configuration and closer to nucleus.
Much greater energy needed to remove the electron
Valence electrons = 2 Group = 2
Valence electron configuration = ns 2
IE 1 2 3 4 kJ mol -1 899 1757 14845 21000
Example 1 :