The energy levels of electrons are K, L, M, N, O, P and Q. Energy levels are also represented by numbers 1 through 7, with K as level 1 and Q as level 7. Within each level are suborbital levels represented as s, p, d, f, g and h.
Energy levels are arranged around the nucleus in concentric orbits. Level K is the closest to the nucleus, while level Q is the furthest. The amount of energy in each level increases in proportion to its distance from the nucleus. Thus, the highest amount of energy is contained in level Q.