Hii,

s, p, d, f and so on are the names given to the orbitals that hold the electrons in atoms.

These orbitals have different shapes (e.g. electron density distributions in space) and energies (e.g. a hydrogen atom with one electron would be denoted as 1s1 - it has one electron in its 1s orbital.

This model depicts that electrons are constantly moving and do not stay fixed as in Bohr's model.

Each orbital can only hold 2 electrons max . There is a hierarchy, i.e. s orbitals will be filled before p orbitals which will be filled before d orbitals and so on.

Once you know the order of orbitals, you can simply fill them according to the number of electrons in the atom. The order for filling orbitals is as follows:

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p, 8s.

The value of spdf : l=0,1,2,3 for s,p,d,f respectively.

spdf designates subshells.

s subshells hold 1 orbital. p holds 3, d holds 5, f holds 7.

The p sublevel has 3 orbitals, so can contain 6 electrons max. The d sublevel has 5 orbitals, so can contain 10 electrons max. And the 4 sublevel has 7 orbitals, so can contain 14 electrons max.

Hope this will help you,

All the very best!!