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