Question

The first ionisation potential in electron volts of nitrogen and oxygen atoms are respectively given by

Answer 1

Answer: 14.6, 13.6
Nitrogen has higher ionization energy than Oxygen because it has a stable half-filled electronic configuration as shown below:
7N(1s)2(2s)2(2px)1(2py)1(2p1)7N(1s)2(2s)2(2px)1(2py)1(2p)1 and 8O(1s)2(2s)2(2px)2(2py)1(2pz)1