When n = 6, l = 0,1, 2, 3, 4, 5. The order in which the energy of the orbitals increases is 6s < 4f < 5d < 6p. The total number of orbitals available are 16 [s = 1, p = 3, d = 5; / = 7]. The maximum number of electrons which an orbtial can contain is 2. Therefore the sixth period can accomodate 32 elements.