Question

What are all of the possible values of l, ml, and ms for n = 4? (select all that apply.)?

Answer 1

For principal quantum number n=4:
1) azimuthal quantum number (l) can be l = 0...n-1:
l = 0, 1, 2, 3. 
The azimuthal quantum number determines its orbital angular momentum and describes the shape of the orbital. 
2) magnetic quantum number (ml) can be ml = -l...+l.
ml = -3, -2, -1, 0, +1, +2, +3.
Magnetic quantum number specify orientation of electrons in magnetic field and number of electron states (orbitals) in subshells.
3) the spin quantum number (ms), is the spin of the electron.
ms = +1/2, -1/2.