Atomic Orbitals

An atom comprises of a nucleus made of protons and neutrons, and an outer shell of electrons.

The electrons are contained at specific energy levels, so that they don't lose energy by radiation. The main shells are identified by the quantum number n, where n = 0, 1, 2, etc. The shells are also named K, L, M, N, etc.

Each shell has a set of subshells, denoted by the quantum number l. l has integer values from 0 up to n-1. This is because for each shell, the number of orbital configurations for each shell is a function of its spherical harmonics. Each of these orbitals are represented by the quantum number m, which ranges from -l to +l. Each orbital can house up to two electrons, both of which have to be in opposing spin conditions, which is denoted by the quantum number s.

s: sharp
p: principal
d: diffuse
f: fundamental