Question

Which of the molecule has pi 2p greater than sigma 2p?

Answer 1

Answer:

The reason for this ordering is that the greater overlap between sigma-oriented p-orbitals gives a greater energy splitting than the pi-oriented orbitals. For the lightest elements, the energy difference between 2s and 2p is unusually small, so there is significant mixing of the 2s MOs with the 2p MOs.