Hydrocarbons are organic compounds which consist of hydrogen and carbon. Carbon atoms may form long chains or ring structures double bonds, to create thousands of different compounds with a variety of properties. Hydrocarbons occur in nature; for example many hydrocarbons are derived from petroleum. Smaller hydrocarbon molecules form gases while intermediate molecules form liquids and larger molecules exist as solids at room temperature.

Our modern way of life depends to a great extent on hydrocarbon compounds. Gasoline, jet fuel, and lubricating oil are mixtures of hydrocarbons that are produced from crude oil. Pipeline gas for heating and cooking is primarily methane, the simplest hydrocarbon molecule. Many other products, such as plastic bottles and synthetic fabrics, are made of chemicals derived from hydrocarbons.

The hydrocarbons form a large and diverse class of substances. Scientists have had to develop an elaborate scheme for naming hydrocarbons in a descriptive way. Basically...