Summarise the rules for writing of distribution of electrons in various shells for the first eighteen elements.

Explanation

The distribution of elements in different orbits is governed by a scheme called Bohr-Bury scheme. There are following rules : (i) The maximum number of electrons present in any shell is given by the formula 2n. Where n = no. of orbit. (ii) The maximum number of electrons that can be accommodated in the outermost shell is 8. (iii) Electrons in an atom do not occupy a new shell unless all the inner shells are completely filled.