Air consists of nitrogen. Revolutionary change in air composition

The air that makes up the earth's atmosphere is a mixture of gases. Dry atmospheric air contains: oxygen 20.95%, nitrogen 78.09%, carbon dioxide 0.03%. Besides, in atmospheric air contains argon, helium, neon, krypton, hydrogen, xenon and other gases. Ozone, nitrogen oxide, iodine, methane, and water vapor are present in small quantities in the atmospheric air.

In addition to the permanent components of the atmosphere, it contains various pollutants introduced into the atmosphere by human production activities.

1. Important integral part atmospheric air is oxygen , the amount of which in the earth's atmosphere is 1.18 · 10 15 tons. A constant oxygen content is maintained due to continuous processes of its exchange in nature. On the one hand, oxygen is consumed during the respiration of humans and animals, spent on maintaining combustion and oxidation processes, on the other hand, it enters the atmosphere through the processes of photosynthesis of plants. Land plants and ocean phytoplankton completely restore the natural loss of oxygen. When the partial pressure of oxygen drops, phenomena may develop oxygen starvation, which is observed when ascending to a height. Critical level is the partial pressure of oxygen below 110 mm Hg. Art. Reducing the partial pressure of oxygen to 50-60 mmHg. Art. usually incompatible with life. Under the influence of short-wave UV radiation with a wavelength of less than 200 nm, oxygen molecules dissociate to form atomic oxygen. The newly formed oxygen atoms are added to the neutral oxygen formula, forming ozone . Simultaneously with the formation of ozone, its decay occurs. The general biological significance of ozone is great: it absorbs short-wave UV radiation, which has a detrimental effect on biological objects. At the same time, ozone absorbs infrared radiation emanating from the Earth, and thereby prevents excessive cooling of its surface. Ozone concentrations are unevenly distributed over altitude. Its greatest quantity is observed at a level of 20-30 km from the Earth's surface.

2. Nitrogen In terms of quantitative content, it is the most significant component of atmospheric air; it belongs to the inert gases. Life is impossible in a nitrogen atmosphere. Air nitrogen is absorbed by certain types of soil bacteria (nitrogen-fixing bacteria), as well as blue-green algae; under the influence of electrical discharges it turns into nitrogen oxides, which, falling with precipitation, enrich the soil with salts of nitrous and nitric acids. Under the influence of soil bacteria, nitrous acid salts are converted into nitric acid salts, which in turn are absorbed by plants and serve for protein synthesis. Along with the absorption of nitrogen in nature, it is released into the atmosphere. Free nitrogen is formed during the combustion processes of wood, coal, and oil; Not a large number of it is formed during the decomposition of organic compounds. Thus, a continuous cycle occurs in nature, as a result of which atmospheric nitrogen is converted into organic compounds, restored and released into the atmosphere, then again bound by biological objects.

Nitrogen is needed as an oxygen diluent because respiration pure oxygen leads to irreversible changes in organism.

However increased content Nitrogen in the inhaled air contributes to the onset of hypoxia due to a decrease in the partial pressure of oxygen. When the nitrogen content in the air increases to 93%, death occurs.

In addition to nitrogen, noble gases of air include argon, neon, helium, krypton and xenon. Chemically, these gases are inert; they dissolve in body fluids depending on the partial pressure; the absolute amount of these gases in the blood and tissues of the body is negligible.

3. An important component of atmospheric air is carbon dioxide (carbon dioxide, carbon dioxide,). In nature, carbon dioxide is found in free and bound states in the amount of 146 billion tons, of which atmospheric air contains only 1.8% of it total number. The bulk of it (up to 70%) is in a dissolved state in the water of the seas and oceans. Some mineral compounds, limestones and dolomites, contain about 22% of the total amount of dioxide and carbon. The rest comes from flora and fauna, coal, oil and humus.

Under natural conditions, continuous processes of release and absorption of carbon dioxide occur. It is released into the atmosphere due to the respiration of humans and animals, the processes of combustion, decay and fermentation, during the industrial roasting of limestone and dolomite, etc. At the same time, in nature there are processes of assimilation of carbon dioxide, which is absorbed by plants during the process of photosynthesis.

Carbon dioxide plays an important role in the life of animals and humans, being a physiological stimulant of the respiratory center.

When large concentrations of carbon dioxide are inhaled, redox processes in the body are disrupted. When its content in the inhaled air increases to 4%, headaches, tinnitus, palpitations, and an excited state are observed; at 8% death occurs.

From a hygienic point of view, the carbon dioxide content is an important indicator by which the degree of air cleanliness in residential and public buildings is judged. The accumulation of large quantities of it in the air of enclosed spaces indicates sanitary problems (overcrowding, poor ventilation).

Under normal conditions, with natural ventilation of the room and infiltration of outside air through the pores building materials The content of carbon dioxide in the air of residential premises does not exceed 0.2%. When its concentration increases indoors, there may be a deterioration in a person’s well-being and a decrease in performance. This is explained by the fact that simultaneously with the increase in the amount of carbon dioxide in the air of residential and public buildings, other properties of the air deteriorate: its temperature and humidity increase, gaseous products of human activity, the so-called anthropotoxins (mercaptan, indole, hydrogen sulfide, ammonia), appear.

With an increase in CO 2 content in the air and a deterioration in meteorological conditions in residential and public buildings, a change in the ionization regime of the air occurs (an increase in the number of heavy ions and a decrease in the number of light ions), which is explained by the absorption of light ions during breathing and contact with skin, as well as the intake of heavy ions with exhaled air.

Maximum permissible concentration of carbon dioxide in the air medical institutions should be considered 0.07%, in the air of residential and public buildings - 0.1%. The last value is accepted as a calculation value when determining the efficiency of ventilation in residential and public buildings.

4. In addition to the main components, atmospheric air contains gases released as a result of natural processes occurring on the surface of the Earth and in the atmosphere.

Hydrogen contained in the air in an amount of 0.00005%. It is formed in high layers of the atmosphere due to the photochemical decomposition of water molecules into oxygen and hydrogen. Hydrogen does not support respiration; in a free state, it is not absorbed and is not released by biological objects. In addition to hydrogen, atmospheric air contains a small amount of methane; Usually the concentration of methane in the air does not exceed 0.00022%. Methane is released during anaerobic decay of organic compounds. How is the component included in the composition? natural gas and gas from oil wells. If you inhale air containing methane in high concentrations, death from asphyxia may occur.

As a product of the decomposition of organic substances, small amounts are present in the atmospheric air ammonia. Its concentrations depend on the degree of contamination of a given area with sewage and organic emissions. In winter, due to the slowdown of decay processes, the ammonia concentration is slightly lower than in summer. During anaerobic processes of decomposition of sulfur-containing organic substances, the formation of hydrogen sulfide, which already in small concentrations gives the air bad smell. Iodine and hydrogen peroxide may be present in small concentrations in atmospheric air. Iodine enters the atmospheric air due to the presence of tiny droplets sea ​​water and seaweed. Due to the interaction of UV rays with air molecules, hydrogen peroxide; Together with ozone, it contributes to the oxidation of organic substances in the atmosphere.

In the atmospheric air there are suspended substances, which are represented by dust of natural and artificial origin. Natural dust includes cosmic, volcanic, terrestrial, sea dust and dust formed during forest fires.

Natural processes play a major role in freeing the atmosphere from suspended substances self-cleaning, among which the dilution of pollution by convection air currents at the Earth's surface is of significant importance. An essential element of atmospheric self-purification is precipitation from the air. large particles dust and soot (sedimentation). As you rise in height, the amount of dust decreases; At an altitude of 7–8 km from the Earth’s surface, there is no dust of terrestrial origin. Significant Atmospheric precipitation plays a role in self-cleaning processes, increasing the amount of settled soot and dust. The dust content in the atmospheric air is affected by meteorological conditions and aerosol dispersion. Coarse dust with a particle diameter of more than 10 microns quickly falls out, fine dust with a particle diameter of less than 0.1 microns practically does not fall out and is suspended.

Composition of the Earth. Air

Air is a mechanical mixture of various gases that make up the Earth's atmosphere. Air is necessary for breathing living organisms , finds wide application

in industry.

The fact that air is a mixture, and not a homogeneous substance, was proven during the experiments of the Scottish scientist Joseph Black. During one of them, the scientist discovered that when white magnesia (magnesium carbonate) is heated, “bound air” is released, that is, carbon dioxide, and burnt magnesia (magnesium oxide) is formed. When burning limestone, on the contrary, “bound air” is removed. Based on these experiments, the scientist concluded that the difference between carbon dioxide and caustic alkalis is that the former contains carbon dioxide, which is one of the constituents of air. Today we know that in addition to carbon dioxide, the composition of the earth’s air includes:

The ratio of gases in the earth's atmosphere indicated in the table is typical for its lower layers, up to an altitude of 120 km. In these areas lies a well-mixed, homogeneous region called the homosphere. Above the homosphere lies the heterosphere, which is characterized by the decomposition of gas molecules into atoms and ions. The regions are separated from each other by a turbo pause.

The chemical reaction in which molecules are decomposed into atoms under the influence of solar and cosmic radiation is called photodissociation. The decay of molecular oxygen produces atomic oxygen, which is the main gas of the atmosphere at altitudes above 200 km. At altitudes above 1200 km, hydrogen and helium, which are the lightest of the gases, begin to predominate. Since the bulk of the air is concentrated in the 3 lower atmospheric layers, changes in air composition at altitudes above 100 km do not have a noticeable effect on general composition

Nitrogen is the most common gas, accounting for more than three-quarters of the Earth's air volume. Modern nitrogen was formed by the oxidation of the early ammonia-hydrogen atmosphere by molecular oxygen, which is formed during photosynthesis. Currently, small amounts of nitrogen enter the atmosphere as a result of denitrification - the process of reducing nitrates to nitrites, followed by the formation of gaseous oxides and molecular nitrogen, which is produced by anaerobic prokaryotes. Some nitrogen enters the atmosphere during volcanic eruptions.

IN upper layers In the atmosphere, when exposed to electrical discharges with the participation of ozone, molecular nitrogen is oxidized to nitrogen monoxide:

N 2 + O 2 → 2NO

Under normal conditions, the monoxide immediately reacts with oxygen to form nitrous oxide:

2NO + O 2 → 2N 2 O

Nitrogen is essential chemical element earth's atmosphere. Nitrogen is part of proteins and provides mineral nutrition plants. It determines the rate of biochemical reactions and plays the role of an oxygen diluent.

The second most common gas in the Earth's atmosphere is oxygen. The formation of this gas is associated with the photosynthetic activity of plants and bacteria. And the more diverse and numerous photosynthetic organisms became, the more significant the process of oxygen content in the atmosphere became. A small amount of heavy oxygen is released during degassing of the mantle.

In the upper layers of the troposphere and stratosphere, under the influence of ultraviolet solar radiation (we denote it as hν), ozone is formed:

O 2 + hν → 2O

As a result of the same ultraviolet radiation, ozone decomposes:

O 3 + hν → O 2 + O

О 3 + O → 2О 2

As a result of the first reaction, atomic oxygen is formed, and as a result of the second, molecular oxygen is formed. All 4 reactions are called the “Chapman mechanism”, named after the British scientist Sidney Chapman who discovered them in 1930.

Oxygen is used for the respiration of living organisms. With its help, oxidation and combustion processes occur.

Ozone serves to protect living organisms from ultraviolet radiation, which causes irreversible mutations. The highest concentration of ozone is observed in the lower stratosphere within the so-called. ozone layer or ozone screen, lying at altitudes of 22-25 km. The ozone content is low: at normal pressure

The formation of the third most common gas in the atmosphere, argon, as well as neon, helium, krypton and xenon, is associated with volcanic eruptions and the decay of radioactive elements.

In particular, helium is a product of the radioactive decay of uranium, thorium and radium: 238 U → 234 Th + α, 230 Th → 226 Ra + 4 He, 226 Ra → 222 Rn + α (in these reactions the α-particle is the helium nucleus, which in During the process of energy loss, it captures electrons and becomes 4 He).

Argon is formed during the decay of the radioactive isotope of potassium: 40 K → 40 Ar + γ.

Neon escapes from igneous rocks.

Krypton is formed as final product decay of uranium (235 U and 238 U) and thorium Th.

The bulk of atmospheric krypton was formed in the early stages of the Earth's evolution as a result of the decay of transuranic elements with a phenomenally short half-life or came from space, where the krypton content is ten million times higher than on Earth.

Xenon is the result of the fission of uranium, but the bulk of this gas remains with early stages formation of the Earth, from the primary atmosphere.

Carbon dioxide enters the atmosphere as a result of volcanic eruptions and during decomposition organic matter. Its content in the atmosphere of the Earth's mid-latitudes varies greatly depending on the seasons of the year: in winter the amount of CO 2 increases, and in summer it decreases.

This fluctuation is associated with the activity of plants that use carbon dioxide in the process of photosynthesis.

Hydrogen is formed as a result of the decomposition of water by solar radiation. But, being the lightest of the gases that make up the atmosphere, it constantly evaporates into outer space, and therefore its content in the atmosphere is very small.

Water vapor is the result of the evaporation of water from the surface of lakes, rivers, seas and land.

The concentration of the main gases in the lower layers of the atmosphere, with the exception of water vapor and carbon dioxide, is constant. In small quantities the atmosphere contains sulfur oxide SO 2, ammonia NH 3, carbon monoxide CO, ozone O 3, hydrogen chloride HCl, hydrogen fluoride HF, nitrogen monoxide NO, hydrocarbons, mercury vapor Hg, iodine I 2 and many others. In the lower atmospheric layer, the troposphere, there is always a large amount of suspended solid and liquid particles. Sources particulate matter in the Earth's atmosphere are, volcanic eruptions plant pollen , microorganisms, and in and human activities, such as the burning of fossil fuels during production. The smallest particles of dust, which are condensation nuclei, cause the formation of fogs and clouds. Without particulate matter constantly present in the atmosphere, precipitation would not fall on Earth.

It cannot be touched and cannot be seen, but the main thing we owe to him is life. Of course, this is the air that was not occupied last place in the folklore of every nation. How the people of antiquity imagined it, and what it really is - I will write about this below.

Gases that make up air

Natural mixture of gases called air. Its necessity and importance for the living cannot be underestimated - it plays important role V oxidative processes, which are accompanied by the release of energy necessary for all living things. Through experiments, scientists were able to determine its exact composition, but the main thing that needs to be understood is it is not a homogeneous substance, but a gas mixture. About 99% of the composition is a mixture of oxygen and nitrogen, and in general air forms the atmosphere of our planet. So, the mixture consists of the following gases:

• methane;
• krypton;
• helium;
• xenon;
• hydrogen;
• neon;
• carbon dioxide;
• oxygen;
• nitrogen;
• argon.

It should be noted that composition is not constant and may vary significantly depending on different areas. For example, large cities have a high carbon dioxide content. In the mountains it will be observed reduced level oxygen, since this gas is heavier than nitrogen, and as it rises its density will decrease. Science says the composition may differ depending on the different parts planets from 1% to 4% for each gas.

In addition to the percentage of gases, air is characterized by the following parameters:

• humidity;
• temperature;
• pressure.

The air is constantly in motion, forming vertical flows. Horizontal - winds, depend on certain natural conditions, therefore they may have different characteristics speed, force and direction.

Air in folklore

Legends of every people endow the air with certain “living” qualities. As a rule, the spirits of this element were elusive and invisible creatures. According to legends, they inhabited mountain tops or clouds, and differed in their predisposition to humans. They were the ones who were thought to be created snowflakes and collected clouds in the clouds, flying across the sky on the winds.

The Egyptians counted the air symbol of life, and the Indians believed that Brahma's exhalation is life, and inhalation, accordingly, means death. As for the Slavs, air (wind) occupied almost a central place in the legends of this people. He could hear and sometimes even fulfill small requests. However, he was not always kind, sometimes siding with the forces of evil. in the form of an evil and unpredictable wanderer.

Air is an essential condition for the life of the vast majority of organisms on our planet.

A person can live for a month without food. Without water - three days. Without air - just a few minutes.

History of the study

Not everyone knows that main component our life activity is an extremely heterogeneous substance. Air is a mixture of gases. Which ones?

For a long time it was believed that air was a single substance and not a mixture of gases. The heterogeneity hypothesis has appeared in the scientific works of many scientists in different time. But no one progressed beyond theoretical guesses. Only in the eighteenth century, Scottish chemist Joseph Black experimentally proved that the gas composition of air is heterogeneous. The discovery was made during subsequent experiments.

Modern scientists have proven that air is a mixture of gases consisting of ten main elements.

The composition differs depending on the location of concentration. Air composition is determined constantly. People's health depends on this. Air is a mixture of what gases?

At higher elevations (especially in the mountains) the oxygen content is low. This concentration is called “rarefied air”. In forests, on the contrary, the oxygen content is maximum. In megacities, the content of carbon dioxide is increased. Determining the composition of air is one of the most important responsibilities of environmental services.

Where can air be used?

• The compressed mass is used when pumping air under pressure. Setting up to ten bar is installed at any tire service station. The tires are inflated with air.
• Workers use jackhammers and pneumatic guns to quickly remove/install nuts and bolts. Such equipment is characterized by low weight and high efficiency.
• In industries using varnishes and paints, it is used to speed up the drying process.
• At car washes, the compressed air mass helps in quickly drying cars;
• Manufacturing enterprises use compressed air to clean tools from all types of contaminants. In this way, entire hangars can be cleared of shavings and sawdust.
• The petrochemical industry can no longer imagine itself without equipment for purging pipelines before the first start-up.
• In the production of oxides and acids.
• To increase the temperature of technological processes;
• They are extracted from the air;

Why do living beings need air?

The main task of air, or rather, one of the main components - oxygen - is to penetrate into cells, as a result of which it promotes oxidation processes. Thanks to this, the body receives energy that is essential for life.

Air enters the body through the lungs, after which it is distributed throughout the body using the circulatory system.

Air is a mixture of what gases? Let's take a closer look at them.

Nitrogen

Air is a mixture of gases, the first of which is nitrogen. Seventh element periodic table Dmitry Mendeleev. The discoverer is considered to be the Scottish chemist Daniel Rutherford in 1772.

Contains proteins and nucleic acids human body. Although its share in cells is small - no more than three percent, the gas is essential for normal life.

Its content in the air is more than seventy-eight percent.

IN normal conditions has no color and odor. Does not combine with other chemical elements.

The largest amount of nitrogen is used in chemical industry, primarily in the manufacture of fertilizers.

Nitrogen is used in medical industry, in the production of dyes,

In cosmetology, acne, scars, warts, and the body's thermoregulation system are treated with gas.

Using nitrogen, ammonia is synthesized and nitric acid is produced.

In the chemical industry, oxygen is used for the oxidation of hydrocarbons in alcohols, acids, aldehydes, and the production of nitric acid.

Fishing industry - saturation of water bodies with oxygen.

But highest value gas has for living beings. With the help of oxygen, the body can utilize (oxidize) the necessary proteins, fats and carbohydrates, converting them into the necessary energy.

Argon

The gas that is part of the air is in third place in importance - argon. The content does not exceed one percent. It is an inert gas without color, taste or smell. Eighteenth element of the periodic table.

The first mention is attributed to an English chemist in 1785. And Lord Larey and William Ramsay received Nobel Prizes for proving the existence of gas and experiments with it.

Areas of application of argon:

• incandescent lamps;
• filling the space between glass panes in plastic windows;
• protective environment during welding;
• fire extinguishing agent;
• for air purification;
• chemical synthesis.

It does not bring any particular benefit to the human body. At high concentrations of gas it leads to suffocation.

Argon cylinders in gray or black.

The remaining seven elements make up 0.03% in air.

Carbon dioxide

Carbon dioxide in the air is colorless and odorless.

Formed as a result of rotting or burning of organic materials, released during breathing and operation of cars and other vehicles.

In the human body, it is formed in tissues as a result of vital processes and is transported throughout venous system into the lungs.

It has positive value, because under load, it expands the capillaries, which allows for greater transport of substances. Positive effect on the myocardium. Helps increase the frequency and strength of the load. Used in the correction of hypoxia. Participates in the regulation of breathing.

In industry, carbon dioxide is obtained from combustion products as a by-product gas. chemical processes or when separating air.

Application is extremely wide:

• preservative in the food industry;
• saturation of drinks;
• fire extinguishers and fire extinguishing systems;
• feeding aquarium plants;
• protective environment during welding;
• use in canisters for gas weapons;
• refrigerant

Neon

Air is a mixture of gases, the fifth of which is neon. It was opened much later - in 1898. The name is translated from Greek as “new”.

A monatomic gas that is colorless and odorless.

Has high electrical conductivity. Has a complete electronic shell. Inert.

Gas is obtained by separating air.

Application:

• Inert environment in industry;
• Refrigerant in cryogenic installations;
• Filler for gas discharge lamps. Found widespread use thanks to advertising. Most colored signs are made using neon. When an electric discharge is passed through, the lamps produce a bright colored glow.
• Signal lights at lighthouses and airfields. They perform well in heavy fogs.
• Air mixture element for people when working with high pressure.

Helium

Helium is a colorless and odorless monatomic gas.

Application:

• Like neon, when passed through an electrical discharge it produces a bright light.
• In industry - to remove impurities from steel during smelting;
• Refrigerant.
• Filling of airships and balloons;
• Partially in breathing mixtures during deep dives.
• Coolant in nuclear reactors.
• The main joy of children is flying balloons.

It is not of particular benefit to living organisms. In high concentrations it can cause poisoning.

Methane

Air is a mixture of gases, the seventh of which is methane. Gas is colorless and odorless. In high concentrations it is explosive. Therefore, odorants are added to it for indication.

It is most often used as fuel and raw material in organic synthesis.

Home furnaces, boilers, and geysers operate primarily on methane.

A product of the vital activity of microorganisms.

Krypton

Krypton is an inert monatomic gas without color or odor.

Application:

• in the production of lasers;
• rocket fuel oxidizer;
• filling incandescent lamps.

The effect on the human body has been little studied. Application in deep sea diving is being studied.

Hydrogen

Hydrogen is a colorless flammable gas.

Application:

• Chemical industry - production of ammonia, soap, plastics.
• Filling spherical shells in meteorology.
• Rocket fuel.
• Cooling of electric generators.

Xenon

Xenon is a monatomic colorless gas.

Application:

• filling incandescent lamps;
• in spacecraft engines;
• as an anesthetic.

It is harmless to the human body. Not particularly useful.

Young children often ask their parents about what air is and what it usually consists of. But not every adult can answer correctly. Of course, everyone studied the structure of air at school in natural history lessons, but over the years this knowledge could be forgotten. Let's try to make up for them.

What is Air?

Air is a unique “substance”. You can't see it, touch it, it's tasteless. This is why it is so difficult to give a clear definition of what it is. Usually they just say - air is what we breathe. It is around us, although we do not notice it at all. You can only feel it when a strong wind blows or an unpleasant odor appears.

What happens if the air disappears? Without it, not a single living organism can live or work, which means that all people and animals will die. It is indispensable for the breathing process. Important has how clean and healthy the air that everyone breathes is.

Where can I find fresh air?

Most healthy air located:

• In forests, especially pine ones.
• In the mountains.
• Near the sea.

The air in these places has a pleasant aroma and has beneficial properties for the body. This explains why children's health camps and various sanatoriums are located near forests, in the mountains or on the sea coast.

You can enjoy fresh air only away from the city. For this reason, many people buy summer cottages outside settlement. Some move to a temporary or permanent residence in the village and build houses there. Families with small children do this especially often. People are leaving because the air in the city is highly polluted.

Fresh air pollution problem

IN modern world pollution problem environment is especially relevant. The work of modern factories, enterprises, nuclear power plants, and automobiles has a negative impact on nature. They release into the atmosphere harmful substances that pollute the atmosphere. Therefore, very often people in urban areas experience a shortage of fresh air, which is very dangerous.

Heavy air inside a poorly ventilated room is a serious problem, especially if it contains computers and other equipment. Being in such a place, a person may begin to suffocate from lack of air, develop pain in the head, and become weak.

According to statistics compiled by the World Health Organization, about 7 million human deaths per year are associated with the absorption of polluted air outdoors and indoors.

Harmful air is considered one of the main causes of such a terrible disease as cancer. This is what organizations involved in the study of cancer say.

Therefore, it is necessary to take preventive measures.

How to get fresh air?

A person will be healthy if he can breathe fresh air every day. If it is not possible to move out of town because important work, lack of money or for other reasons, then it is necessary to look for a way out of the situation on the spot. So that the body receives the necessary norm fresh air, the following rules should be followed:

1. Be outside more often, for example, take evening walks in parks and gardens.
2. Go for a walk in the forest on weekends.
3. Constantly ventilate living and working areas.
4. Plant more green plants, especially in offices where there are computers.
5. It is advisable to visit resorts located by the sea or in the mountains once a year.

What gases does air consist of?

Every day, every second, people inhale and exhale without thinking about the air at all. People do not react to him in any way, despite the fact that he surrounds them everywhere. Despite its weightlessness and invisibility for human eye, air has a rather complex structure. It involves the interrelation of several gases:

• Nitrogen.
• Oxygen.
• Argon.
• Carbon dioxide.
• Neon.
• Methane.
• Helium.
• Krypton.
• Hydrogen.
• Xenon.

The main share of air is occupied nitrogen , the mass fraction of which is 78 percent. 21 percent of total number accounts for oxygen - the most essential gas for human life. The remaining percentage is occupied by other gases and water vapor, from which clouds are formed.

The question may arise, why is there so little oxygen, just a little more than 20%? This gas is reactive. Therefore, with an increase in its share in the atmosphere, the likelihood of fires in the world will increase significantly.

What is the air we breathe made of?

The two main gases that make up the air we breathe every day are:

• Oxygen.
• Carbon dioxide.

We inhale oxygen, exhale carbon dioxide. Every schoolchild knows this information. But where does oxygen come from? The main source of oxygen production is green plants. They are also consumers of carbon dioxide.

The world is interesting. In everything that happens life processes the rule of maintaining balance is observed. If something went from somewhere, then something came from somewhere. Same with air. Green spaces produce the oxygen that humanity needs to breathe. Humans consume oxygen and release carbon dioxide, which in turn feeds plants. Thanks to this system of interaction, life exists on planet Earth.

Knowing what the air we breathe consists of and how much it is polluted in modern times, it is necessary to protect the plant world of the planet and do everything possible to increase the number of green plants.

Video about air composition