VSEPR Theory and Orbital Hybridization

Did you know that the shape of a molecule is what determines how you perceive the way something smells? When you breathe, the molecules in the air are carried into your nose past little tiny indentations called receptor sites. If a particular molecule is the right size and shape, it will fit into certain receptor sites. These receptor sites transmit an impulse to your brain which identifies it as a certain recognizable smell. Your nose is very sensitive to different odors because these receptor sites are very good at detecting small differences in molecular shape.

Of course, your nose knows nothing about the VSEPR theory. The VSEPR theory is used to predict molecular shape. VSEPR theory is based on the fact that an electron pair will repel each other, whether they are bonding or non-bonding electrons. The number of pairs of electrons around the central atom directly determines the shape of a molecule. All two atom molecules are linear in shape. Two regions of electron density around a central atom also results in a linear molecule. Three regions of electron pairs results in trigonal planar and four regions produces a tetrahedral shape. Keep in mind that unshared or non-bonding electrons also affect the overall geometric shape.