Question

Fluorine is most electronegative element of periodic table but its electron gain enthalpy is less than that of chlorine. Explain.

Answer 1

Answer:

Because fluorine is a very small atom in comparison with chlorine , when fluorine gains a electron , the electronic repulsion between the electrons increases which decreases the electron gain enthalpy in comparison with chlorine .

Answer 2

Answer:

Due to variation in atomic radii

Explanation:

Fluorine has a van der Waal radius of about 147pm whereas Chlorine has a van der Waal radius of 177pm. Due to smaller size, the repulsions between the electrons of Fluorine is greater than that of Chlorine thus reducing its ∆egH.