The magnetic quantum number is the third set of quantum numbers which describe the unique quantum state of an electron. It is denoted by letter ml . The magnetic quantum number denotes the energy levels available with in a subshell. ml can take value from -l to +l.
- l=0 . s orbital has only one subshell. Therefore the ml of an electron in an s orbital will always be 0 ( m=0 ).
- l=1. p orbital has three subshells. Therefore the ml of an electron in an p orbital will be ml = -1,0,+1. This would represents the three different orientations in p orbital. They are usually defined as px, py, pz.
- l=2. f orbital has five subshell. Therefore the ml of an f orbital will be ml = -2, -1, 0, +1, +2