The angular momentum quantum number is a number that specifies the shape of an orbital with a principal quantum number. The secondary quantum number divides shells into subshells, or smaller groups of orbitals.
The number of angular nodes is equal to the value of the angular momentum quantum number, which is why the angular momentum quantum number is so important. It is responsible for determining the shape of the orbital and the angular distribution.
A letter code is used to identify the quantum number so that there is no confusion with "n." Each value of I is equal to a specific subsection, which are each unique in their shapes. The values are represented by a s, p, d, f subshells. Unlike n, the value of I can be zero and it can also be positive, but it cannot be less than one.
Another type of quantum number that is used in these equations is the magnetic quantum number. The magnetic quantum number is responsible for determining the number of orbitals and the orbital direction and orientation within each individual subshell. This number can anywhere from -1 to +1; therefore, the magnetic quantum number can be zero, a positive number, or a negative number.
Another type of quantum number is the electron spin quantum number, which is responsible for the direction of the electron spin and it does not depend on any other quantum number.