Answer:
n is the principal quantum number, it specifies the energy and average distance from the nucleus
l is the orbital quantum number, it specifies the subshell/orbital shape
ml is the magnetic quantum number and specifies the orbital orientation
Explanation:
The Schrödinger wave equation is solved for the hydrogen atom to yield three sets of quantum numbers.
The principal quantum number corresponds to the energy level in the Bohr model and also shows the average distance of the electron from the nucleus.
The orbital quantum number reveals the subshell where an electron is found as well as the shape of the orbital. E.g p-orbitals are dumbbell shaped.
The magnetic quantum number shows the orientation of an orbital in space. Its values range from -l to +l