Final answer:
The air found in the products of combustion after the complete combustion of natural gas or propane is called exhaust gas or flue gas. These gases can include carbon dioxide, water vapor, and other by-products.
Step-by-step explanation:
The air found in the products of combustion after the complete combustion of natural gas or propane is called exhaust gas or flue gas. These gases are emitted as a result of the combustion of fuels such as natural gas or propane. They can include carbon dioxide, water vapor, and other by-products.