Question

Why electron gain enthalpy of element group two is low

Answer 1

Answer:

because the atomic size of the atoms became increase and effective nuclear charge decareas hence the attraction by the nucleus on additional electron decrease

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.