What are the primary results of combustion?

The primary results of combustion primarily include smoke, flame, heat, and various gases. When a substance burns, it undergoes a chemical reaction known as combustion, which predominantly involves the reaction of a fuel with oxygen. This reaction produces heat and light, manifested as flame. Additionally, the process releases gases, often including carbon dioxide and water vapor, along with other byproducts depending on the fuel type and combustion conditions.

Smoke is another significant outcome of combustion, resulting from unburned particles and various chemicals that are released. The presence of these substances contributes to the environmental effects of combustion, such as air pollution. Thus, the characteristics of combustion are well represented by smoke, flame, heat, and gases, making this answer the most accurate in the context of the question regarding primary combustion results.