Question

Define octet rule.Write its two limitations.​

Answer 1

The tendency to of making eight electrons in its valence shell is called octet rule.

(1) Hydrogen with 1 electron attains stability by sharing, gaining or losing 1 valence electron. It does not need to complete octet to attain stability. Also, He has only 2 electrons and is stables.

Incomplete octet: In certain molecules such as BeH

2

, BeCl

2

, BH

3

, BF

3

, the central atom has less than 8 electrons in its valence shell, yet the molecule is stable.