| Term | Definition |
| fuel | a substance that provides energy as the result of a chemical change |
| energy transformation | a change from one for to another; also called an energy conversion |
| combustion | the process of burning a fuel |
| hydrocarbon | an energy-rich compound that contains carbon and hydrogen atoms |
| petroleum | liquid fossil fuel;oil |
| refinery | a factory in which crude oil is heated and separated into fuels and other products |
| petrochemical | a compound made from oil |
| fossil fuel | an energy-rich substance (such as coal,oil, or natural gas) formed from the remains of organisms |