Question

Electron gain enthalpy of fluorine (F) is less negative than that of chlorine (Cl). Why ?

Answer 1

Hi,

The size of fluorine atom is small. As a result, there are strong electron-electron repulsions in the compact 2p-orbital. Thus, the electron gain enthalpy of fluorine is less negative than that of chlorine.




 

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.