Name the most electronegative element. Is it also having the highest electron gain enthalpy? Why or why not?

Explanation

The most electronegative element is fluorine (4.0). Fluorine do not have the highest EA value. Among halogens, Cl has the highest EA value. The EA values are in the order, `Cl > F > Br > I > At`.
Reason: The size of F atom is small, compared to the size of Cl atom. The addition of one electron to F atom produces high electron density around it. Then the electron repuslions increase in F atom. Because of this, F atom shows lesser tendency to attract another electron towards it and form `F^(-)` ion. Hence F has low EA than that of Cl.