What is complete combustion in natural gas primarily composed of?

Complete combustion of natural gas primarily occurs when methane (CH4) reacts with oxygen (O2) to produce carbon dioxide (CO2), water (H2O), heat, and light. The primary byproducts of complete combustion are carbon dioxide and water vapor, which are non-toxic and indicate that the combustion process is efficient.

The presence of heat and light is characteristic of combustion reactions, which release energy. When natural gas undergoes complete combustion, there are minimal emissions of carbon monoxide (CO) or other incomplete combustion products, indicating that the process is efficient and produces a cleaner burn.

In this context, while the other options present various combinations of compounds, they do not accurately reflect the complete combustion process of natural gas. For instance, carbon monoxide and other byproducts would suggest incomplete combustion, and carbon dioxide combined with hydrogen and oxygen does not reflect the products involved in complete combustion. Therefore, the choice that includes both CO2 and H2O alongside heat and light precisely defines the complete combustion of natural gas.