Question #7216f

A moving electron is an electric current and every electric current carries a magnetic field.

Consider the p orbitals which align themselves along the x, y and z axis. They are said to be * degenerate* ** which means they are of equal energy.

If a strong magnetic field is applied this causes the orbitals to have slightly different energies depending on whether they are aligned with the field or against it.

The principle quantum number is #n# and takes integral values 0, 1, 2 etc. This describes the energy level an electron is in.

The angular momentum quantum number is #l# and can take values 0 up to #(n-1)#. This gives the sub - shell the electron is in.

The magnetic quantum number, to which your question refers is #m# can take values #-l# through zero to #+l#

The next quantum number is #s# the spin quantum number and can take values of #+1/2# or #-1/2#. This is usually shown as #uarr# or #darr#.

As an example suppose #n=2#
So #l# can take values of 0 and 1
0 corresponds to 2s and 1 corresponds to 2p
#m# is therefore zero for the 2s electron but for 2p can take values of -1, 0 and +1. This gives rise to the 3 orbitals in the diagram.

An important principle was put forward by Pauli which states that in an atom, no 2 electrons can have all 4 quantum numbers the same.

This forms the basis by which atoms are built up.