Question

Draw for yourself the energy-level diagram showing the hybrid orbitals formed in the C atom when it bonds. Now look at those hybrid orbitals and those of the N atom, and describe how the bonding with a N atom will differ with the bonding that occurs with a C atom, even though both atoms have four hybrid orbitals oriented in a tetrahedral shape.

Answer 1

I don't know how you would draw an energy level diagram of the hybrid orbtials, still less how that would help you interpret the sigma bonding in C-C versus C-N. You could certainly draw the energy level diagram of the AOs and LCAO MOs, and that would perhaps be of interest -- but that's MO theory, not valence bond theory.