What term describes a rapid chemical reaction that gives off energy and products of combustion that are very different in composition from the fuel and oxygen that combined to produce them?

• A. Physical Change
• B. Exothermic Reaction
• C. Fire
• D. Chemical Reaction

Answer: (C)

Fire captures the observable result of a rapid combustion process. When a fuel meets an oxidizer, they react quickly, releasing energy as heat and light and forming new products such as carbon dioxide and water that are chemically different from the original fuel and oxygen. That combination of rapid energy release and new combustion products is what makes the term fire the best fit for the description.

Physical change doesn’t involve forming new chemical products, so it doesn’t match. An exothermic reaction describes energy release but doesn’t by itself describe the rapid flame-producing process or the specific combustion products. A chemical reaction is too general and doesn’t specify the rapid, flame-producing nature of combustion.