Why do atoms combine?
Why are only certain combinations possible? Why do
molecules possess definite shapes? To answer such
questions different theories and concepts have been put
forward from time to time.
In this fourth unit of class 11 chemistry, we can answer the above questions by learning Kössel-Lewis
approach, Valence Shell Electron Pair Repulsion (VSEPR)
Theory, Valence Bond (VB) Theory and Molecular Orbital
(MO) Theory.