The order of electron affinity for $F, Cl, Br,$ and $I$ is .....

Which of the following elements have the highest and lowest electron gain enthalpy,respectively?

Which of the following represents the correct order of increasing electron gain enthalpy (with negative sign) for the elements?
$a.$ Nitrogen
$b.$ Phosphorus
$c.$ Chlorine
$d.$ Fluorine

Select the equations that represent an endothermic step.

The electron gain enthalpy $\Delta_{eg}H$ of $Cl_{(g)}$ is $-349 \ kJ \ mol^{-1}$. If the ground state energy of $Cl_{(g)}$ is $x \ kJ \ mol^{-1}$,the ground state energy (in $kJ \ mol^{-1}$) of $Cl^{-}_{(g)}$ is

Which one of the following arrangements represents the correct order of least negative to most negative electron gain enthalpy for $C, Ca, Al, F$ and $O$?