What does combustion refer to in a scientific context?

Combustion in a scientific context specifically refers to a chemical reaction that occurs when a substance, typically a fuel, reacts with oxygen, resulting in the release of heat and light. This exothermic reaction produces byproducts, commonly including carbon dioxide and water, depending on the type of fuel being burned. The heat and light released during this process is what makes combustion a crucial reaction for various applications, such as in engines, heating systems, and cooking.

The other options describe different processes or concepts that do not align with the defined characteristics of combustion. For instance, the cooling down of substances is unrelated to the combustion process, as combustion inherently involves an increase in temperature and energy release. Similarly, while burning does produce gases, the definition of combustion itself specifically emphasizes the reaction with oxygen and the resultant heat and light, rather than merely the gases produced. Lastly, while energy transformation is a fundamental concept in many scientific processes, combustion is distinct in that it refers specifically to the reaction involving oxygen and the release of energy rather than just any change in energy form.