Question

electron gain enthalpy of halogens has a large negative value but that of noble gases is positive. why?​

Answer 1

Answer:

The electron gain enthalpy for halogens is highly negative because they can acquire the nearest stable noble gas configuration by accepting an extra electron. Noble gases have large positive electron gain enthalpy. This is because the extra electron is placed in the next higher principal quantum energy levels.

Answer 2

Answer:

Why Noble Gases have +ve value for Electron Affinity?

➡️ Due to stable Noble gas configuration ,they do not accept an electron and hence they have a large positive electron gain enthalpy.

An electron to enter the next higher principal quantum level which leads to a very unstable electronic configuration.