Nitrogen has positive electron gain enthalpy whereas oxygen has negative. However, oxygen has lower ionisation enthalpy than nitrogen. Explain.

Nitrogen has positive electron gain enthalpy whereas oxygen has negati

1.	Nitrogen has positive electron gain enthalpy whereas oxygen has negative. However, oxygen has lower ionisation enthalpy than nitrogen. Explain.
Answer» Solution :Electronic CONFIGURATION of `""_(7)N=1s^(1),2s^(2),2p_(x)^(1), 1p_(y)^(1),2p_(z)^(1)` Nitrogen has STABLE configuration because porbital is halfly filled. Adding an extra electron needs an energy into the p-orbital. Electronic configuration of `""_(8)O=1s^(2),2s^(2),2p_(x)^(2),2p_(y)^(1),2p_(z)^(1)` Oxygen has 4 ELECTRONS, in p-orbital, so process of adding an electron to that orbital is an exothermic process. Oxygen has lower ionisation enthalpy than nitrogen because if we remove one electron from 2p-orbitaloxygen attends stable configuration, i.e., `2p^(3)`. In nitrogen removal of last electron is not easy, one of the three 2p-electrons due to its stable configuration.