sp² Hybridisation
The mixing of one s and two p orbitals to give three hybrid orbitals in a plane at 120° to each other.
Formula / equation
3 hybrids, 120°
Unit
degrees
In depth
One p orbital remains unhybridised and perpendicular to the plane, available for pi bonding. This arrangement produces the trigonal planar geometry of alkenes, carbonyl compounds and aromatic rings, and the parallel p orbitals it leaves behind are what allow pi electrons to delocalise across conjugated systems.
Examples in the real world
Ethene, benzene, the boron in BF₃, and the carbonyl carbon of a ketone.