What does complete combustion produce?

Complete combustion occurs when a fuel is burned in the presence of sufficient oxygen, leading to the most efficient reaction possible. This process primarily breaks down hydrocarbon fuels, such as those found in natural gas, propane, and wood. The products of complete combustion are water vapor and carbon dioxide, both of which result from the combination of the hydrogen and carbon components of the fuel with oxygen.

In addition, complete combustion generates heat, which is the energy released during this chemical reaction. The term "non-combustible ashes" refers to the solid residues that may remain from burning certain fuels, particularly wood, which comprises minerals and other non-combustible materials present in the original fuel.

Thus, the correct option reflects that when you have complete combustion, you will see the formation of water vapor, carbon dioxide, heat energy, and some non-combustible ashes, making this the most accurate representation of the combustion process. It encapsulates all byproducts expected when combustion occurs fully and efficiently, adhering to the principles of thermodynamics and combustion science.