Magnetic Quantum number| Simple Examples

The magnetic quantum number, often denoted by the symbol “m_l,” is one of the quantum numbers that describes the orientation of an electron orbital in space within an atom. Here’s a concise definition of the magnetic quantum number:

  • The magnetic quantum number, represented by “m_l,” specifies the orientation of an electron orbital in a magnetic field.
  • It can have integer values ranging from -l to +l, where “l” is the angular momentum quantum number.
  • The magnetic quantum number determines the number of possible orientations (or spatial orientations) for an orbital within a sublevel.
  • The values of m_l provide information about the spatial orientation of an orbital within a specific sublevel of a principal energy level.

The magnetic quantum number (ml​) is dependent on the angular momentum quantum number (l) and has integer values ranging from −l to +l. Here are examples of magnetic quantum numbers for specific sublevels within different principal energy levels:


For the s sublevel (l=0):

  • If l=0, then ml can only be 0. For example:
    • In the n=1 energy level, the s sublevel has l=0, so ml=0.

For the p sublevel (l=1):

  • If l=1, then ml can be −1,0,1. For example:
    • In the n=2 energy level, the p sublevel has l=1, so ml=−1,0,1.

For the d sublevel (l=2):

  • If l=2, then ml can be −2,−1,0,1,2. For example:
    • In the n=3 energy level, the d sublevel has l=2, so ml=−2,−1,0,1,2.

principal quantum numbers, magnetic quantum numbers, spin quantum numbers
Author: U Javaid