Question

(a) Arrange the following as per the instructions given in the brackets
(iv) Cl, F, Br, I (Increasing order of electron affinity)

Answer 1

Electron affinity:-

• It is the amount of energy released when an electron is added to a neutral atom in order to form an anion.
• It increases across a period from left to right, due to the increase in nuclear charge and small size of an atom.
• Electron affinity decreases down the group due to an increase in atomic radius.
• Here, Though fluorine is the most electronegative atom it has a lower electron affinity than chlorine. It is due to their compact atomic size which propels its high electron density inside the atom.
• Increasing order of electron affinity - $\mathrm{I}<\mathrm{Br}<\mathrm{F}<\mathrm{Cl}$