(a) **Bohr-Buiy Rules :**

(i) The maximum no. of electrons present in a shell is given by the formula 2n^2 (where n is shell no.).

(ii) The maximum no. of electrons that can be accommodated in the outermost orbit is 8.

**Bohr-Buiy Rules :**

(i) The maximum no. of electrons present in a shell is given by the formula 2n^2 (where n is shell no.).

(ii) The maximum no. of electrons that can be accommodated in the outermost orbit is 8.