The second electron gain enthalpy of an element:

The electron affinity values (in $kJ \ mol^{-1}$) for halogens $X, Y,$ and $Z$ are $-349, -333,$ and $-325$ respectively. Therefore,$X, Y,$ and $Z$ are respectively which of the following?

The second electron gain enthalpies (in $kJ \ mol^{-1}$) of oxygen and sulphur respectively are

Which of the following represents the correct order of increasing electron gain enthalpy with negative sign for the elements $O$,$S$,$F$ and $Cl$?

The correct order of electron affinity of $B, C, N, O$ is

The correct pair of electron affinity order is