Question

Why chlorine has higher negative electron gain enthalpy than f?

Answer 1

As electron gain enthalpy means ability to accept electrons.....

Fluorine .....atomic number... 9
chlorine...... atomic number... 17
thus ability to accept electrons will be more in chlorine due to large size of the atom.... than fluorine being small

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.