Quantum Number

There are four quantum numbers, which are

Principal Quantum Number

It is denoted by “n” and determines the energy levels of the atoms.

NB: Maximum possible number of electrons in a shell is 2n2.
The shells are K, L, M, N, O, P, and Q, which mean 1, 2, 3, 4, 5, 6, 7, respectively.

The subsidiary

It is also called the azimuthal quantum number. It shows the energy sub-levels in each shell. It ranges from 0 to (n-1 ). It Es represented by “L”.

The magnetic

It is represented by “m” and shows the orientation of the shells. It ranges from – L through O to L.


It shows the spinning of the electrons. It is represented by “s” and has values – ½ and ½.

Leave a Comment

not allowed!