Question

The element that has highest electron gain enthalpy is

Answer 1

Although fluorine is most electronegative element but chlorine has more electron gain enthalpy. This is because of the small size of the fluorine so addition of electron is not favorable process because repulsion between the electrons takes place.

Answer 2

Answer:

1) Halogens (F, C1, Br, I, At) in group 17 have very high negative values of electron gain enthalpy as they acquire stable electronic configuration of noble gas on addition of one electron.

(2) Noble gases in group 18 show high positive values of electron gain enthalpy because the added electron has to enter the next higher shell. This is very unstable electronic configuration. (due to high shielding effect and low effective nuclear charge.)

(3) The alkali metals have very low negative electron gain enthalpy values.