Which term best describes a reaction where a fuel reacts with oxygen to produce heat and light?

• A. Combustion
• B. Decomposition
• C. Precipitation
• D. Synthesis

Answer: (A)

Combustion is the correct idea: a fuel reacting with oxygen to produce heat and light. This is a type of exothermic oxidation, where energy is released as heat (and often visible flames). The other terms describe different kinds of reactions—decomposition involves breaking a compound into simpler substances, precipitation is the formation of a solid from ions in solution, and synthesis is combining simple substances into a more complex one. None of those inherently capture the burning with oxygen that releases heat and light, which is characteristic of combustion.