hybridization
As discussed in the electron configuration section when electrons bond they fill orbitals. One might think that the s, p, and d orbitals are different in the bonds. This would make sense but experimental data shows that all the bonding orbitals in many molecules are the same. The way that this occurs is through Hybridization. The hybrid orbitals are formed by combining s, p and d orbitals. If a molecule has three bonds it needs three orbitals. So the first three orbitals that are used are an s and two p orbitals. The hybrid orbital that is formed is called a sp2 orbital. All three of the orbitals are the same.
If the molecule has the triginal bipyramid shape then the molecule has sp3d. (This is because it has five bonds so it needs five orbitals.)
