# Azimuthal Quantum Number and Magnetic Quantum Number

I know that azimuthal quantum numbers and magnetic quantum numbers are used to find the no. of and the orientation of subshells respectively, but why do they have to be called so?

I reckon that azimuth means the angle w.r.t North or something but have no idea so as to why magnetic quantum no. has to be called so, doesn’t the spin of an electron determine its magnetic properties? So won’t the spin quantum number be a better choice to express the magnetic properties? How does the 3D orientation of orbitals have something to do with the term ‘magnetic quantum number’? Similarly for azimuthal quantum no. and it’s relation with the no. of subshells .

• I'm afraid I don't follow your answer. (1) What is "magnetic momentum"? (2) How does that relate to the name "azimuthal"? (3) What does spin-orbit coupling have to do with any of this? The azimuthal and magnetic quantum numbers are $l$ and $m_l$ respectively, we aren't even beginning to deal with spin here. – orthocresol Jul 27 at 4:27