4p electron orbitals, computer model. An electron orbital is a region around an atomic nucleus (not seen) in which one or a pair of electrons is most likely to exist. The three 4p orbitals are each made up of six lobes, three pairs centred on the nucleus that decrease in size towards it. They are part of the 4 shell, which also contains a spherical 4s orbital at lower energy, and five 4d orbitals and seven 4f orbitals at a higher energy (not seen).