Short answers, pulled from the story.
Ethylene or ethene is the most produced organic compound on Earth with hundreds of millions of tonnes manufactured annually. Its primary industrial use is polymerizing into polyethylene to form plastics that wrap food, line pipes, and create consumer goods.
The bond angles around each carbon atom in an alkene measure approximately 120 degrees according to the VSEPR model. The double bond is shorter than a single bond measuring 1.33 angstroms compared to the 1.53 angstroms of a typical single bond.
The formula C6H14 can exist as thirteen different isomers ranging from 1-hexene to 2,3-dimethyl-2-butene. Their differences are determined by the spatial arrangement of groups attached to the double bond creating cis and trans configurations or E and Z isomers.
The production of alkenes on an industrial scale relies on the process of hydrocarbon cracking where raw materials are broken apart at high temperatures. In the United States and the Middle East ethane and propane serve as the primary feedstocks while Europe and Asia rely more heavily on naphtha.
Ethylene acts as a hormone that influences the ripening of fruit by triggering the conversion of starches to sugars and the softening of cell walls. Plants are the main natural source of alkenes in the form of terpenes which include pigments like lycopene carotene and xanthophylls.