pi bonds

[Adrienne_4F]

How do we explain pi bonds using hybridization? There was an example from class for C2H4, but I don't understand it.

[Elena Saab 4A]

If you have an sp2 hybridized orbital, there is one p orbital left that is not hybridized. When you are filling electrons into the orbitals, the energy difference between sp2 and p is very small (because you can think of sp2 as an average of s and 2 p orbitals), so it is more energy favorable for the electrons to enter into the p orbital rather than having a lone pair in one of the hybridized orbital. When a bond forms with the unhybridized orbital, it is a pi bond.

[Nicklas_Wright_1A]

Pi bonds do not involve hybridization.

[Tinisha 1G]

Sigma bonds are involved in hybridization, but pi bonds are not involved in hybridization.