Which term describes a rapid chemical reaction that releases energy and produces combustion products different in composition from the original fuel and oxygen?

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

Answer: (B)

Fire is the rapid oxidation of a fuel in the presence of an oxidizer, releasing energy as heat and light and forming combustion products such as carbon dioxide and water that are chemically different from the starting fuel and oxygen. This description matches exactly the rapid, energy-releasing process that creates new substances through combustion, which is what we recognize as fire.

Physical change doesn’t involve making new chemicals or releasing heat in a sustained way. A chemical reaction is any rearrangement of atoms, but not all are rapid or involve combustion products. An exothermic reaction releases energy, but it isn’t necessarily rapid or producing the specific combustion products associated with burning.