Gasoline contains a number of different compounds, but they all have the common feature of bonded chains or rings of carbon atoms with hydrogen atoms attached. Type into your browser: molecules in gasoline images/
They are all highly flammable combining with oxygen to release energy and the byproducts carbon dioxide and water vapor. Students may undertake using models to demonstrate such reactions. The same sort of reaction applies to fats, oils, wax, wood, and other organic compounds. (To find exact molecular arrangements of such compounds, Google: molecular structure of ____.)