Out of H and H_(2) , the latter has higher first ionization energy while out of O and O_(2) , the former has higher first ionization energy . Explain why .

Out of H and H_(2) , the latter has higher first ionization energy whi

1.	Out of H and H_(2) , the latter has higher first ionization energy while out of O and O_(2) , the former has higher first ionization energy . Explain why .
Answer» <P> Solution :In `H_(2)` , FIRST electron has to be REMOVED from `sigma` (1s) which has lower energy (more stable ) than H-atom . In `O_(2)` first electron has to be removed from `pi^() (2p_(x)) or pi^() (2p_(y))` ORBITALS which has HIGHER energy than 2 p - orbital of O-atom .