Which of the following arrangements for the three halogens $Cl$,$Br$,and $I$ when placed in the order of their increasing electron affinity is correct?

What is the correct order of electron affinity for $B, C, N$,and $O$?

The electron affinity of chlorine is $3.7 \ eV$. $1 \ g$ of chlorine is completely converted to $Cl^-$ ion in a gaseous state. $(1 \ eV = 23.06 \ kcal \ mol^{-1})$. Energy released in the process is $...... \ kcal$.

The amount of energy released on the addition of an electron in the outermost shell of an atom is called:

In which of the following processes is energy liberated?

Which one has maximum electron affinity?