Figure 9.38 When the 2s and 2p orbitals interact, the 2s MO falls in energy and the 2p MO rises in energy. For O2, F2, and Ne2, the interaction is small, and the 2p MO remains below the 2p MOs, as in Figure 9.36. For B2, C2, and N2 the 2s—2p interaction is great enough that the 2p MO rises above the 2p MOs, as shown on the right.