True or False and explain why

Question

True or False and explain why: In the valence bond treatment, a pi bond is formed when two 2p orbitals overlap side to side.

Answer 1

True. A linear overlap of atomic orbitals, whether s-s, s-p, or p-p, results in a so-called sigma (σ) bond. If the p-p overlap is side to side (i.e., parallel) we have a pi (π) bond. A pi bond will only exist if a sigma already is present. That is, the 2nd (or 3rd) bond in a double (or triple) bond would be a pi-bond.