Question

Electron gain enthalpy of oxygen is less than sulphur's due to its compact nature (it will suffer interelectronic repulsion), but why does EGE become less negative after sulphur ? (Down the group, atomic size increases, so how can size be attributed to EGE in this case?) if it is not size, then what is the deciding factor?

Answer 1

The size of oxygen (atomic) is less than that of sulphur. Hence the electronic repulsions are maximum due to oppositely charged electrons and protons .thus E.A of oxygen is less than sulphur