Which of the following arrangement for the three halogens Cl, Br and I when placed in the order of their increasing electron afinity is correct?
I< Br< Cl
Electron affinity is the tendency of an atom to accept electrons.
Down the group the radius of the atom increases. This increases the amount of shielding its outer electrons receive. It is, therefore, harder for the positive nucleus to attract electrons. Hence, it decreases as we go down the group.
So, the correct option is B.