Question

out of the following which have which has more negative electron gain enthalpy justify your answer f o c l

Answer 1

Cl is the most electronegative. This can be explained by the following.

F is more electron than O this can be explained in terms of the smaller size of F atoms and increased nuclear charge which is more than that of O even after a slight decrease due to the forces of repulsion as explained above.

But, Cl is more electronegative than F because as we move from Cl to F the atomic size increases. This leads to repulsion among the electrons so the electronegativity of F decreases

Answer 2

Answer:

The negative electron gain enthalpy of fluorine is less than that of chlorine. It is due to small size of fluorine atom. As a result, there are strong interelectronic repulsions in the relatively small 2p orbitals of fluorine and thus, the incoming electron does not experience much attraction.