F ELECTRON ORBITALS. “The electron orbital letters go in the order s, p, d, f, g, h, i, j, etc. At the fourth and higher levels, there are seven f orbitals in addition to the 4s, 4p, and 4d orbitals. Counting the 4s, 4p, and 4d orbitals, this makes a total of 16 orbitals in the fourth level. They have even more complicated shapes. s, p, d, and f orbitals are available at all higher energy levels as well.” (Great graphics).