# What are sp2 hybrid orbitals?

An $s {p}^{2}$ orbital is made of 1 s orbital and 2 p orbitals.
Aluminum number 13 has three valance electrons. One of the two electrons in the s orbital can promoted to a p orbital. There is one electron originally in the one of the three p orbitals. With the new promoted electron this gives 2 p orbitals each with 1 electron and 1 s orbital with 1 electron. These three orbital hybridize to form three $s {p}^{2}$ orbitals.