Question

Among f and cl which will have electron gain enthalpy

Answer 1

Here Cl and F both are halogens butelectron gain enthalpy of Cl is more negative than F because of very small size of F which causes interelectronic repulsion among its electrons

Answer 2

Answer:

Due to its small size, the electron–electron repulsions in the relatively compact 2p-sub-shell are comparatively large, and hence, the incoming electron is not accepted with the same ease as is the case with larger Cl atom. Consequently, electron gain enthalpy of Cl is more negative than that of F.