Question

Be and ne have positive values of electron gain enthalpy againstgeneral trend in period

Answer 1

The electronic configuration of Be is 2s2, Since it has completely filled outer shells which is a stable configuration. It becomes energetically unfavourable to remove or add an electron and it has positive electron gain enthalpy.

Similarly, Ne is a noble gas and fully filled outer shell thus its electron gain enthalpy is positive.

Answer 2

Explanation:

In Be, the extra electron is to be addedx in 2p orbital because 2s orbital is completely filled and in Ne, it is to be added to a noble gas configuration