Worksheet ? Hybridization One model to explain bonding in molecules is called the valence bond theory. It is based on the concept of hybridized molecular orbitals. Atomic orbitals (s,p,d) are mathematically mixed to form molecular orbitals with defined shapes and energy levels. In organic chemistry, we need only look at the hybridization of the one 2s and three 2p orbitals containing the valence electrons of C,O and N. When four equivalent molecular orbitals are needed, all four atomic orbitals are mixed to give sp3 hybridization. When three equivalent molecular orbitals are needed, three of the atomic orbitals are mixed to give sp2 hybridization. In this case, one unhybridized p atomic orbital remains, with its shape and energy level