# Explaining why s and p orbitals do not interact

While going through molecular orbital theory, my chemistry teacher mentioned that the reason why there is no significant interaction between $$\ce {s}$$ orbitals on one atom and $$\ce {p_x}$$ and $$\ce {p_y}$$ orbitals on another atom is that the $$\ce {s}$$ orbitals interact with both lobes of the $$\ce {p}$$ orbitals, having both in phase and anti phase interactions with these $$\ce {p}$$ orbitals, taking the z axis to be the internuclear axis.

However, I read that orbitals which do not have the right symmetry simply cannot interact, i.e. their overlap integral is necessarily $$\ce {0}$$. Thus, is the reasoning given by my chemistry teacher actually valid?

• There is no contradiction behind your "however". It is the same in other words. Jan 12 '19 at 14:49