What are the shells where electrons can be found?

Electrons are found in parts of an atom called shells that cover different energy levels and are referred to by the letters K, L, M, N, O, P and Q.

The K shell has the lowest energy level in an atom, while the Q shell has the highest. Each shell can only hold a certain maximum number of electrons. Within each shell, electrons are located in subshells or suborbitals. These subshells are named by the letters s, p, d, f, g and h. As with the main shells, the subshells are also limited in the number of electrons each can contain.