What must be true for combustion to occur?

For combustion to occur, the fuel/air mixture must be in the proper ratio. This means that there needs to be a specific balance between the amount of fuel and the amount of oxygen available for the combustion process. If the ratio is too rich (too much fuel) or too lean (too much air), the combustion will either be incomplete or may not ignite at all. The ideal mixture ensures that the fuel burns efficiently to release energy.

Combustion is a chemical reaction that requires a fuel source, oxygen, and heat. While temperatures significantly affect the ignition process, there is no requirement for the fuel to be in a solid state, nor is it correct that the temperature must be below freezing for combustion to take place. In fact, many fuels are liquids or gases when they ignite. Additionally, the presence of oxygen is crucial for combustion; without it, the process cannot occur. Thus, having the correct fuel/air mixture is essential for effective combustion.