Class 11 Chemistry Chemical Bonding Structure Kossel and Lewis approach

Kossel and Lewis approach

It was given by Lewis and Kossel. These two volunteers actually gave us the reason behind bond formation. According to them “only outer electrons participate in bond formation and inner electrons remain protected. These valence electrons taking part in bond formation are represented by putting dots around symbol of element”.

The representation of valence electrons is shown as such:


The atom with one electron is monovalent. The atom with two electrons is divalent, with three is trivalent and so on.



  1. According to it, highly electronegative atoms like halogens are at extreme right and electropositive atoms like alkali metals are at extreme left.

The halogen, for completing orbit gains 1 electron and alkali metals looses 1 electron to attain stable configuration.

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