Characteristics and functions of components in the air

The composition of the air is dominated by nitrogen and oxygen.

The primitive atmosphere is dominated by carbon dioxide, carbon monoxide, and methane.

Nitrogen 78%, oxygen 21%, rare gases, carbon dioxide, other gases and impurities account for nitrogen: nitrogen has a wide range of uses in the national economy and daily life. First of all, taking advantage of its "lonely" characteristic, we fill it in the light bulb, which can prevent the oxidation of tungsten filament and slow down the volatilization rate of tungsten filament, and prolong the service life of the bulb.

It can also be used instead of inert gas as a shielding gas when welding metals.

Oxygen: 1Metallurgical industry blows high-purity oxygen in the steelmaking process, and oxygen reacts with carbon and phosphorus, sulfur, silicon, etc., which not only reduces the carbon content of steel, but also helps to remove impurities such as phosphorus, sulfur and silicon.

In addition, the heat generated during the oxidation process is sufficient to maintain the temperature required for the steelmaking process, so the oxygen blowing not only shortens the smelting time, but also improves the quality of the steel. When blast furnace ironmaking, increasing the oxygen concentration in the blast can reduce the coke ratio and increase the output. In non-ferrous metal smelting, the use of oxygen enrichment can also shorten the smelting time and increase the output.

2.Chemical industry In the production of ammonia, oxygen is mainly used for the oxidation of feedstock gases, such as high-temperature cracking of heavy oil and gasification of pulverized coal, to strengthen the process and increase fertilizer production. 3 Healthcare:

Supply respiration: for hypoxia, hypoxia or none.

Oxygen environment, e.g. diving, mountaineering, high-altitude flight, astronautics, medical rescue, etc.

In addition, oxygen has a wide range of uses in metal cutting and welding.

The normal air composition by volume fraction is: nitrogen (N2) accounts for 78 08, oxygen (O2) accounts for 20 95, argon (Ar) accounts for 0 93, carbon dioxide (C02) accounts for 0 03, and trace amounts of noble gases, such as helium (He), neon (Ne), krypton (Kr), xenon (XE), etc. Ozone (O3), nitrogen oxide (NO), nitrogen dioxide (NO2) except O2 can breathe, CO2 photosynthesis, others are unknown.

The main components of air are nitrogen and oxygen. The normal air composition by volume fraction is: nitrogen (N2) accounts for about 78%, oxygen (O2) accounts for about 21%, rare gases account for about helium HE, neon Ne, argon argon, krypton KR, xenon XE, radon RN), carbon dioxide (CO2), and other gases and impurities account for about about ozone (O3), nitric oxide (NO), nitrogen dioxide (NO2), water vapor (H2O), etc.

The differences between air and oxygen are:1. The composition is different.

Air is a mixture of nitrogen, oxygen, noble gases (helium, neon, argon, krypton, xenon, radon, gas), carbon dioxide and other substances (e.g. water vapor, impurities, etc.). Oxygen, on the other hand, is a pure substance that contains only oxygen itself.

2. The physical properties are different.

At 0 and one standard atmosphere (PA) the air density is. The molar volume is mol. The relative density of oxygen is, water 1), relative vapor density air 1), saturation vapor pressure.

The main components of the air are nitrogen, oxygen, noble gases, carbon dioxide, and other substances (such as water vapor, impurities, etc.).

Air is a mixture, and its composition is very complex, mainly as a result of various changes in nature compensating for each other. The variable components of air are carbon dioxide and water vapor.

The adventitious composition of the air varies completely from region to region. For example, the air near the factory may contain ammonia and acid vapor depending on the production project. In addition, the air contains very small amounts of hydrogen, ozone, nitrogen oxides, methane and other gases.

Dust is a more or less suspended impurity in the air.

In general, the composition of air is generally relatively fixed. This is very important for the survival of humans and other animals and plants. However, with the development of modern industry, the harmful gases and soot emitted into the air have changed the composition of the air and caused air pollution.

Polluted air can seriously damage human health, affect the growth of crops, and cause damage to natural resources and buildings.

The earth's atmosphere is mainly composed of 78% nitrogen, 21% oxygen, noble gases, carbon dioxide, other gases and impurities*, impurity gases*, and a density of .

Noble gases: helium HE, neon Ne, argon AR, krypton KR, xenon XE, radon RN, and the recently discovered UUO7 elements.

Impurity gases: carbon dioxide, sulfur dioxide, nitrogen dioxide, ozone, etc.

Air is the gas that surrounds the Earth. It is layered on the earth's surface, transparent and colorless and odorless, it is mainly composed of nitrogen and oxygen, and has an important impact on human survival and production. Air is a mixture of gases in the earth's atmosphere, which is mainly composed of nitrogen, oxygen, noble gases (helium, neon, argon, krypton, xenon, radon), carbon dioxide and other substances (such as water vapor, impurities, etc.).

Among them, the volume fraction of nitrogen is about 78%, the volume fraction of oxygen is about 21%, the volume fraction of rare gases (helium, neon, argon, krypton, xenon, radon) is about, the volume fraction of carbon dioxide is about, and the volume fraction of other substances (such as water vapor, impurities, etc.) is about.

The composition ratio of air varies with altitude and air pressure. Historically, humans thought that air was a single substance, until the French scientist Lavoisier first came to the conclusion that air is composed of oxygen and nitrogen through experiments. At the end of the 19th century, scientists discovered through a large number of experiments that there were still rare gases such as helium, argon, and xenon in the air.

Air: In its natural state, air is colorless and odorless. Oxygen in the air is necessary for all aerobic organisms. All animals need to breathe oxygen, as do the respiration of green plants.

In addition, green plants use carbon dioxide in the air for photosynthesis, and air is almost the only carbon dioxide required by all plants.