Oil and natural gas are naturally occurring chemicals that are made up of just two elements -- carbon and hydrogen. The class of chemicals based on carbon and hydrogen are called hydrocarbons.
The simplest hydrocarbon, methane, is made up of one carbon atom and four hydrogen atoms. Other hydrocarbons like octane and octadecane have more complicated structures. Plastics are made of molecules called polymers that are very long chains of hydrocarbons.
Click on the name of each hydrocarbon in the illustration to learn more.»next