Explain in briefl, the significance of azimuthal quantum number.

It is denoted by the letter"l" where it signifies the orientation of the orbit where the electron is revolving around the nucleus
S- 1 so l is 0
P-2 so l is 1
D-3 so l is 2
F-4 so l is 3
And so on even for g and h but no electron is identified so numbering is not given