Which statement best describes combustion?

Combustion is defined as a chemical reaction where a substance reacts with oxygen, typically resulting in the production of heat and light. This reaction is generally exothermic, meaning it releases energy in the form of heat, which is a fundamental characteristic of combustion processes. Common examples of combustion include burning fossil fuels, wood, and other organic materials, all of which involve a rapid reaction with oxygen that produces carbon dioxide and water as byproducts.

This understanding clarifies that combustion is not limited to liquid substances, as it can occur in solids and gases as well. Additionally, while enzymes facilitate many biological reactions, they are not involved in combustion processes. Lastly, combustion is inherently associated with significant energy changes, making the assertion that it lacks energy changes incorrect. Thus, the definition of combustion being a reaction where a substance combines with oxygen is the most accurate and comprehensive description of the concept.