What two substances are involved in the fire chemical reaction?

The fire chemical reaction is fundamentally based on the process of combustion, which requires two essential components: oxygen and fuel. In this context, oxygen serves as the oxidizing agent, while fuel is the combustible material that can vary from solids like wood to liquids like gasoline or gases like propane.

When fuel combines with oxygen in the presence of an ignition source (like heat), a chemical reaction occurs that produces fire. This reaction releases energy in the form of heat and light, which is what we perceive as flames. Therefore, the correct choice emphasizes the vital role that both oxygen and fuel play in sustaining a fire.

Oxygen is abundant in the atmosphere, making it readily available for combustion processes. The fuel source provides the necessary material for the reaction, leading to the continuation of the fire as long as both elements are present and there is sufficient heat to maintain the reaction.