Alkene
An unsaturated hydrocarbon containing at least one carbon–carbon double bond.
Formula / equation
CₙH₂ₙ
Unit
Dimensionless
In depth
The doubly bonded carbons are sp² hybridised and planar, and the pi bond prevents rotation, which gives rise to cis–trans isomerism. That electron-rich pi bond makes alkenes far more reactive than alkanes, readily undergoing electrophilic addition.
Examples in the real world
Ethene, the most-produced organic chemical; but-2-ene; the polyunsaturated chains in vegetable oils.