[The legend]

By a general rule the electron affinity of elements increases from left to right along the period and decreases down a group. Then why does chlorine have more electron affinity than fluorine even though it is below fluorine in the periodic table?



My attempt)
actually, i thought it maybe so because of more electrons in Cl but then that reasoning should hold for the rest of the elements too.which actually doesnt... so i have no idea..

[Cherriyan]

Electron affinity of Cl being greater than F is an exception. This is due to extremely small size of F atom which leads to great inter electronic repulsions in F atom.