VSEPR theorem

The expanded form of VSEPR is Valence Shell Electron Pair Repulsion. In 1970 scientist R.G Gillespie proposed Valence Shell Electron Pair Repulsion theorem that is simply expressed as VSEPR theorem. VSEPR theorem is established on the basis of Lewis structure of molecules. According to the Lewis structure of molecule, the central atoms valence shell contains electrons as pairs and more electron pairs may exists in valence shell. In a molecule the electron pairs tends to place them as far as possible from each others to minimise the repulsion between the pairs of electrons. Hence, different molecules are found in different shapes. Just for example the carbon di oxide is linear in structure. On the other hand the structure of water is just like English alphabet V. The every structure of molecules are the result of the electron pair repulsion of valence shell of the central atom. From different arrangement of the electron pair of valence shell of the central atom of the molecule, the angle of paired electron, atom and paired electron bond angle 180 degree ensures minimum repulsion between the electron pairs. 180 degree angle also ensures the maximum distance of the electron pairs. 180 degree of angle also ensures the shapes of molecule as linear and straight line structure.