Hydrocarbon
Definition
A compound of only hydrogen and carbon: the family behind fuels, plastics, and natural gas.
Technical definition
A hydrocarbon is an organic compound composed exclusively of hydrogen and carbon atoms, classified as aliphatic (alkanes, alkenes, alkynes) or aromatic. They are nonpolar, burn cleanly in excess oxygen to CO2 and H2O, and form the feedstock of the petrochemical industry.
Example
Methane (CH4, natural gas), octane (C8H18, gasoline), and benzene (C6H6) are all hydrocarbons.
Common confusion
Hydrocarbons contain ONLY carbon and hydrogen. Add oxygen, like ethanol (C2H6O), and it is an organic compound but not a hydrocarbon.