What defines the process of combustion?

The process of combustion is best defined as a chemical process that produces heat and light. This definition captures the essence of combustion, which involves a rapid chemical reaction between a fuel and an oxidant, typically oxygen, leading to the release of energy in the form of heat and light. This reaction is exothermic, meaning it releases more energy than it consumes, resulting in the characteristic flames and heat associated with fire.

Combustion reactions are essential for understanding fire dynamics and are critical in fire investigations, as they explain how various materials can ignite and sustain a flame under the right conditions. The generation of light is also significant, as it helps in identifying and observing the combustion process during an investigation.

In contrast, the other options do not accurately describe combustion. A slow oxidation process without heat release does not involve the rapid energy release typical of combustion. A physical breakdown of materials refers to changes in physical states rather than chemical reactions. Finally, a chemical reaction that only creates gas overlooks other products of combustion, such as heat and light, which are key characteristics of the process.