alkene

American  

[al-keen] / ˈæl kin /

noun

Chemistry.

1. any member of the alkene series.

---

alkene British  

/ ˈælkiːn /

noun

1. 1. Also called: olefine.   olefin.  any unsaturated aliphatic hydrocarbon with the general formula C n H 2n

   2. Also called: olefine.  ( as modifier )

      alkene series

---

alkene Scientific  

/ ăl′kēn′ /

1. Any of a group of unsaturated hydrocarbons that have carbon atoms in chains linked by one or more double bonds and that have the general formula C _n H _2n. Lighter alkenes, such as ethylene, are derived from petroleum by cracking.

2. Also called olefin

3. ◆ The group of alkenes as a whole is called the alkene series or the ethylene series. Its first five members are ethylene (or ethene), propylene (or propene), butylene (or butene), pentene, and hexene.

---

Etymology

Origin of alkene

First recorded in 1895–1900; alk(yl) + -ene

Example Sentences

According to the researchers, the reactions proceed rapidly because the alkene carbons in cubene and quadricyclene are severely pyramidalized instead of flat.

From Science Daily • Jan. 23, 2026

For example, halogens add to the double bond in an alkene instead of replacing hydrogen, as occurs in an alkane:

From Textbooks • Feb. 14, 2019

Benzene does not, however, exhibit the characteristics typical of an alkene.

From Textbooks • Feb. 14, 2019

The hybridization of the carbon atoms in the double bond in an alkene changes from sp2 to sp3 during an addition reaction.

From Textbooks • Feb. 14, 2019

The name of an alkene is derived from the name of the alkane with the same number of carbon atoms.

From Textbooks • Feb. 14, 2019