The electron gain enthalpy (in $kJ/mol$) of fluorine,chlorine,bromine and iodine,respectively,are:

Which element has the highest electron gain enthalpy?

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

What is the correct order of electron affinity for the given groups?

Consider the following conversions:
$(i) \ O_{(g)} + e^- \to O^{-}_{(g)} ; \Delta H_1$
$(ii) \ F_{(g)} + e^- \to F^{-}_{(g)} ; \Delta H_2$
$(iii) \ Cl_{(g)} + e^- \to Cl^{-}_{(g)} ; \Delta H_3$
$(iv) \ Na_{(g)} \to Na^{+}_{(g)} + e^- ; \Delta H_4$
Which of the following statements is incorrect?

The correct order of the electron gain enthalpy of the given elements is