There is a thick layer of air on the surface of the earth where we live, which not only plays a role in regulating the climate, but also is the life pillar of human beings and all animals and plants.

The volume fraction of (1) air is about 78% nitrogen, 2 1% oxygen, 0.94% rare gas, 0.03% carbon dioxide and 0.03% other gases and impurities.

(2) lavoisier first made a quantitative experimental study and came to the conclusion that air is composed of nitrogen and oxygen.

(3) The development of modern industry will consume a lot of fossil fuels, and the pollutants produced by its combustion are the main pollutants of air pollution. Fossil fuels often contain carbon, sulfur, nitrogen and other elements, and combustion products will contain co; Inhalable particles such as SO2NO2 smoke and dust.

(4) The answer is reasonable from the point of view of reducing pollutant emissions and absorbing or eliminating air pollutants.

So the answer is: (1) 78%; 0.03%; ② lavoisier;

(3) carbon monoxide; SO2NO2 inhalable particulate matter;

(4) replacing coal with clean energy; The flue gas produced by the factory is discharged after being treated.