Bohr-Bury scheme –

i. The maximum number of electrons that could be present in a shell is given by the rule 2n², where n is the orbit number or energy level.

Example, in first shell, n = 1, then number of electrons = 2

Similarly for other shells, the diagram is shown below:

ii. The maximum number of electrons that can be accommodated in the outermost orbit is 8.

iii. Electrons are not accommodated in a given shell unless all the inner shells are completely filled.