Alkene الألكينات و الألكاينات (الفصل 3 ) Alkenes and Alkynes Alkene One of the class of acyclic hydrocarbons containing one or more carbon-tocarbon double bonds. Alkenes (also called olefins) and alkynes (also called acetylenes) together constitute the family of organic compounds called unsaturated hydrocarbons, since they contain less than the number of hydrogens found in