Question

1. Why would you expect phosphorus to require less ionization energy than sulphur to remove a valence electron.

2. sulphur actually requires less ionization energy than phosphorus. Using their electron configurations, explain why sulphur has less ionization energy than phosphorus.

3. As we go down the halogen group of elements why does the electron affinity become smaller?

Answer 1

2 . Sulphur has p^4 configuration which will become p^3 (stable half filled ) after ionisation that is why Sulphur ionises easily and thus requires less ionisation energy .

But P has already half filled stable p^3 configuration which requires more energy for ionisation .