# What are the four quantum numbers and the properties to which they refer?

$n , l , {m}_{l} ,$ and ${m}_{s}$; details below.
$n$: the principal quantum number relates the size of the electron orbital
$l$: the angular quantum number relates shape of the electron orbital
${m}_{l}$: the magnetic quantum number relates the spatial orientation of the electron orbital
${m}_{s}$: the magnetic spin quantum number relates the rotational direction of each electron within an orbital (at most two at a time in accordance with the Pauli exclusion principle)