CBSE Class 11-science Answered

Limitations of octet rule:

• The incomplete octet of the central atom

            In some compounds, the number of electrons surrounding the central atom is less than eight.

            This is especially the case with elements having less than four valence electrons. Examples are LiCl, BeH₂ and BCl₃.

• In a number of compounds of thir period elements, there are more than eight valence electrons around the central atom. 

            Examples of such compounds are SF₆, H₂SO₄.

• The rule is based on inert nature of noble gases. However, some noble gases (for example xenon and krypton) combine with oxygen