METHOD OF REPRESENTING SUBSHELL ELECTRONIC CONFIGURATION
FILLING OF ELECTRONS IN THE SUBSHELL:

When electrons are added to the subshells of atoms, they are filled in the order from lower energy subshell to higher energy. This is called the subshell electronic configuration of atoms. The maximum number of electrons that can be accommodated in each subshell is given in the table below:

The subshells in the increasing order of their energies are given below:

1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5s < 4d < 5p < 6s < 4f<..........