Final answer:
Flue gas analysis typically includes elements such as oxygen, carbon, hydrogen, and nitrogen, which are detected through combustion analysis of hydrocarbons and are also common components of the atmosphere.
Step-by-step explanation:
The elements that appear in flue gas analysis typically include oxygen, carbon, hydrogen, and nitrogen. This is because a common method to determine the elemental composition of an unknown hydrocarbon is through combustion analysis. When a sample is burned in an oxygen atmosphere, the resulting gaseous products, which include CO₂ (carbon dioxide), H₂O (water vapor), N₂ (nitrogen), and possibly SO₂ (sulfur dioxide) if sulfur is present, are analyzed. Furthermore, the air we breathe is primarily composed of nitrogen and oxygen, along with water vapor, CO₂, noble gases, and methane, which indicates that elements such as oxygen and nitrogen are also part of the mix of gases commonly found in the atmosphere.