Question

sumarise the limitation of octet rule

Answer 1

From the word 'octet' itself we can understand i.e. 8.So therefore according to the rule of octet it can contain 8 electrons in its outer-most shell.

Answer 2

Answer:

Octet rule fails to explain the following:

(1) The stability of incomplete octet molecules, i.e., the molecules with the central atom containing less than eight electrons.

For example, $\sf{BeCl_2}, {BF_3}$.

(2) The stability of expanded octet molecules, i.e., the molecules with the central atom containing more than eight electrons.

For example, $\sf{PC_5}, {SF_6}$.

(3) Observed shape and geometry of the molecules.

(4) Difference in energies and reactivities of different molecules.