Question

which will show lowest ionisation potential?​

Answer 1

Answer:

Clearly, Option 1 Electronic configuration which is

[He] 2s2 will have the lowest ionisation potential since lesser the electrons easier it is to remove the electron from the attraction of the nucleus , however once that more and more electrons are filled, the corresponding attraction of the nucleus increases more and hence it becomes then difficult to remove an electron from the outermost Shell of atom.