What gases does air consist of? Gas composition of atmospheric air.

17.10.2019

Atmospheric air is a mixture of various gases. It contains constant components of the atmosphere (oxygen, nitrogen, carbon dioxide), inert gases (argon, helium, neon, krypton, hydrogen, xenon, radon), small amounts of ozone, nitrous oxide, methane, iodine, water vapor, as well as in varying amounts, various impurities of natural origin and pollution resulting from human production activities.

Oxygen (O2) is the most important part of the air for humans. It is necessary for the implementation of oxidative processes in the body. In the atmospheric air, the oxygen content is 20.95%, in the air exhaled by a person - 15.4-16%. Its decrease in atmospheric air to 13-15% leads to a violation of physiological functions, and to 7-8% - to death.

Nitrogen (N) - is the main component of atmospheric air. The air inhaled and exhaled by a person contains approximately the same amount of nitrogen - 78.97-79.2%. The biological role of nitrogen lies mainly in the fact that it is a diluent of oxygen, since life is impossible in pure oxygen. With an increase in the nitrogen content to 93%, death occurs.

Carbon dioxide (carbon dioxide), CO2 - is a physiological regulator of respiration. The content in clean air is 0.03%, in exhaled by a person - 3%.

A decrease in the concentration of CO2 in the inhaled air is not dangerous, because. the necessary level of it in the blood is maintained by regulatory mechanisms due to the release during metabolic processes.

An increase in the content of carbon dioxide in the inhaled air up to 0.2% causes a person to feel unwell, at 3-4% there is an excited state, headache, tinnitus, palpitations, slowing of the pulse, and at 8% there is severe poisoning, loss of consciousness and death comes.

Recently, the concentration of carbon dioxide in the air of industrial cities has been increasing as a result of intense air pollution by fuel combustion products. An increase in CO2 in the atmospheric air leads to the appearance of toxic fogs in cities and the "greenhouse effect" associated with the delay of the thermal radiation of the earth by carbon dioxide.

An increase in the CO2 content above the established norm indicates a general deterioration in the sanitary condition of the air, since along with carbon dioxide other toxic substances may accumulate, the ionization regime may worsen, dust and microbial contamination may increase.

Ozone (O3). Its main quantity is noted at the level of 20-30 km from the Earth's surface. The surface layers of the atmosphere contain a negligible amount of ozone - no more than 0.000001 mg/l. Ozone protects the living organisms of the earth from the damaging effects of short-wave ultraviolet radiation and at the same time absorbs long-wave infrared radiation coming from the Earth, protecting it from excessive cooling. Ozone has oxidizing properties, so its concentration in the polluted air of cities is lower than in rural areas. In this regard, ozone was considered an indicator of the purity of the air. However, recently it has been established that ozone is formed as a result of photochemical reactions during the formation of smog, therefore, the detection of ozone in the atmospheric air of large cities is considered an indicator of its pollution.

Inert gases - do not have a pronounced hygienic and physiological significance.

Human economic and industrial activity is a source of air pollution with various gaseous impurities and suspended particles. The increased content of harmful substances in the atmosphere and indoor air adversely affects the human body. In this regard, the most important hygienic task is the regulation of their permissible content in the air.

The sanitary and hygienic state of the air is usually assessed by the maximum permissible concentrations (MPC) of harmful substances in the air of the working area.

The MPC of harmful substances in the air of the working area is the concentration that, during daily 8-hour work, but not more than 41 hours a week, during the entire working experience does not cause diseases or deviations in the state of health of the present and subsequent generations. Establish the MPC average daily and maximum one-time (action up to 30 minutes in the air of the working area). MPC for the same substance may be different depending on the duration of its exposure to humans.

At food enterprises, the main causes of air pollution with harmful substances are violations of the technological process and emergency situations (sewerage, ventilation, etc.).

Hygienic hazards in indoor air are carbon monoxide, ammonia, hydrogen sulfide, sulfur dioxide, dust, etc., as well as air pollution by microorganisms.

Carbon monoxide (CO) is an odorless and colorless gas that enters the air as a product of incomplete combustion of liquid and solid fuels. It causes acute poisoning at an air concentration of 220-500 mg/m3 and chronic poisoning at a constant inhalation of a concentration of 20-30 mg/m3. The average daily MPC of carbon monoxide in the atmospheric air is 1 mg/m3, in the air of the working area - from 20 to 200 mg/m3 (depending on the duration of work).

Sulfur dioxide (S02) is the most common air pollutant, as sulfur is found in various fuels. This gas has a general toxic effect and causes respiratory diseases. The irritating effect of the gas is detected when its concentration in the air is more than 20 mg/m3. In the atmospheric air, the average daily maximum allowable concentration of sulfur dioxide is 0.05 mg/m3, in the air of the working area - 10 mg/m3.

Hydrogen sulfide (H2S) - usually enters the atmospheric air with waste from chemical, oil refineries and metallurgical plants, and is also formed and can pollute indoor air as a result of decay of food waste and protein products. Hydrogen sulfide has a general toxic effect and causes discomfort in humans at a concentration of 0.04-0.12 mg/m3, and a concentration of more than 1000 mg/m3 can be fatal. In the atmospheric air, the average daily allowable concentration of hydrogen sulfide is 0.008 mg/m3, in the air of the working area - up to 10 mg/m3.

Ammonia (NH3) - accumulates in the air of enclosed spaces during the decay of protein products, malfunctions of refrigeration units with ammonia cooling, in case of accidents in sewer facilities, etc. It is toxic to the body.

Acrolein is a product of the decomposition of fat during heat treatment, which can cause allergic diseases under industrial conditions. MPC in the working area - 0.2 mg/m3.

Polycyclic aromatic hydrocarbons (PAHs) - their association with the development of malignant neoplasms has been noted. The most common and most active of them is 3-4-benz (a) pyrene, which is released during the combustion of fuel: coal, oil, gasoline, gas. The maximum amount of 3-4-benzo(a)pyrene is released during the combustion of coal, the minimum - during the combustion of gas. In food processing plants, long-term use of overheated fat can be a source of PAH air pollution. The average daily MPC of cyclic aromatic hydrocarbons in the atmospheric air should not exceed 0.001 mg/m3.

Mechanical impurities - dust, soil particles, smoke, ash, soot. Dustiness increases with insufficient landscaping of the territory, unimproved access roads, violation of the collection and removal of production waste, as well as violation of the sanitary cleaning regime (dry or irregular wet cleaning, etc.). In addition, the dustiness of the premises increases with violations in the device and operation of ventilation, planning decisions (for example, with insufficient isolation of the pantry of vegetables from production workshops, etc.).

The impact of dust on a person depends on the size of dust particles and their specific gravity. The most dangerous for humans are dust particles smaller than 1 micron in diameter, because they easily penetrate the lungs and can cause their chronic disease (pneumoconiosis). Dust containing impurities of toxic chemical compounds has a toxic effect on the body.

MPC for soot and soot is strictly regulated due to the content of carcinogenic hydrocarbons (PAH): the average daily MPC for soot is 0.05 mg/m3.

In high-capacity confectionery workshops, dustiness of the air with sugar and flour dust is possible. Flour dust in the form of aerosols can cause irritation of the respiratory tract, as well as allergic diseases. MPC flour dust in the working area should not exceed 6 mg/m3. Within these limits (2-6 mg/m3), maximum allowable concentrations of other types of vegetable dust containing no more than 0.2% of silicon compounds are regulated.

The structure and composition of the Earth's atmosphere, it must be said, were not always constant values in one or another period of the development of our planet. Today, the vertical structure of this element, which has a total "thickness" of 1.5-2.0 thousand km, is represented by several main layers, including:

Troposphere.
tropopause.
Stratosphere.
Stratopause.
mesosphere and mesopause.
Thermosphere.
exosphere.

Basic elements of the atmosphere

The troposphere is a layer in which strong vertical and horizontal movements are observed, it is here that weather, precipitation, and climatic conditions are formed. It extends for 7-8 kilometers from the surface of the planet almost everywhere, with the exception of the polar regions (there - up to 15 km). In the troposphere, there is a gradual decrease in temperature, approximately 6.4 ° C with each kilometer of altitude. This figure may differ for different latitudes and seasons.

The composition of the Earth's atmosphere in this part is represented by the following elements and their percentages:

Nitrogen - about 78 percent;

Oxygen - almost 21 percent;

Argon - about one percent;

Carbon dioxide - less than 0.05%.

Single composition up to a height of 90 kilometers

In addition, dust, water droplets, water vapor, combustion products, ice crystals, sea salts, many aerosol particles, etc. can be found here. This composition of the Earth’s atmosphere is observed up to approximately ninety kilometers in height, so the air is approximately the same in chemical composition, not only in the troposphere, but also in the upper layers. But there the atmosphere has fundamentally different physical properties. The layer that has a common chemical composition is called the homosphere.

What other elements are in the Earth's atmosphere? As a percentage (by volume, in dry air), gases such as krypton (about 1.14 x 10 -4), xenon (8.7 x 10 -7), hydrogen (5.0 x 10 -5), methane (about 1.7 x 10 - 4), nitrous oxide (5.0 x 10 -5), etc. In terms of mass percentage of the listed components, nitrous oxide and hydrogen are the most, followed by helium, krypton, etc.

Physical properties of different atmospheric layers

The physical properties of the troposphere are closely related to its attachment to the surface of the planet. From here, the reflected solar heat in the form of infrared rays is sent back up, including the processes of thermal conduction and convection. That is why the temperature drops with distance from the earth's surface. This phenomenon is observed up to the height of the stratosphere (11-17 kilometers), then the temperature becomes practically unchanged up to the level of 34-35 km, and then there is again an increase in temperatures up to heights of 50 kilometers (the upper boundary of the stratosphere). Between the stratosphere and the troposphere there is a thin intermediate layer of the tropopause (up to 1-2 km), where constant temperatures are observed above the equator - about minus 70 ° C and below. Above the poles, the tropopause "warms up" in summer to minus 45°C, in winter temperatures here fluctuate around -65°C.

The gas composition of the Earth's atmosphere includes such an important element as ozone. There is relatively little of it near the surface (ten to the minus sixth power of a percent), since the gas is formed under the influence of sunlight from atomic oxygen in the upper parts of the atmosphere. In particular, most of the ozone is at an altitude of about 25 km, and the entire "ozone screen" is located in areas from 7-8 km in the region of the poles, from 18 km at the equator and up to fifty kilometers in general above the surface of the planet.

Atmosphere protects from solar radiation

The composition of the air of the Earth's atmosphere plays a very important role in the preservation of life, since individual chemical elements and compositions successfully limit the access of solar radiation to the earth's surface and people, animals, and plants living on it. For example, water vapor molecules effectively absorb almost all ranges of infrared radiation, except for lengths in the range from 8 to 13 microns. Ozone, on the other hand, absorbs ultraviolet up to a wavelength of 3100 A. Without its thin layer (on average 3 mm if placed on the surface of the planet), only water at a depth of more than 10 meters and underground caves, where solar radiation does not reach, can be inhabited. .

Zero Celsius at stratopause

Between the next two levels of the atmosphere, the stratosphere and the mesosphere, there is a remarkable layer - the stratopause. It approximately corresponds to the height of ozone maxima and here a relatively comfortable temperature for humans is observed - about 0°C. Above the stratopause, in the mesosphere (begins somewhere at an altitude of 50 km and ends at an altitude of 80-90 km), there is again a drop in temperature with increasing distance from the Earth's surface (up to minus 70-80 ° C). In the mesosphere, meteors usually burn out completely.

In the thermosphere - plus 2000 K!

The chemical composition of the Earth's atmosphere in the thermosphere (begins after the mesopause from altitudes of about 85-90 to 800 km) determines the possibility of such a phenomenon as the gradual heating of layers of very rarefied "air" under the influence of solar radiation. In this part of the "air blanket" of the planet, temperatures from 200 to 2000 K occur, which are obtained in connection with the ionization of oxygen (above 300 km is atomic oxygen), as well as the recombination of oxygen atoms into molecules, accompanied by the release of a large amount of heat. The thermosphere is where the auroras originate.

Above the thermosphere is the exosphere - the outer layer of the atmosphere, from which light and rapidly moving hydrogen atoms can escape into outer space. The chemical composition of the Earth's atmosphere here is represented more by individual oxygen atoms in the lower layers, helium atoms in the middle, and almost exclusively hydrogen atoms in the upper. High temperatures prevail here - about 3000 K and there is no atmospheric pressure.

How was the earth's atmosphere formed?

But, as mentioned above, the planet did not always have such a composition of the atmosphere. In total, there are three concepts of the origin of this element. The first hypothesis assumes that the atmosphere was taken in the process of accretion from a protoplanetary cloud. However, today this theory is subject to significant criticism, since such a primary atmosphere must have been destroyed by the solar "wind" from a star in our planetary system. In addition, it is assumed that volatile elements could not stay in the zone of formation of planets like the terrestrial group due to too high temperatures.

The composition of the Earth's primary atmosphere, as suggested by the second hypothesis, could be formed due to the active bombardment of the surface by asteroids and comets that arrived from the vicinity of the solar system in the early stages of development. It is quite difficult to confirm or refute this concept.

Experiment at IDG RAS

The most plausible is the third hypothesis, which believes that the atmosphere appeared as a result of the release of gases from the mantle of the earth's crust about 4 billion years ago. This concept was tested at the Institute of Geology and Geochemistry of the Russian Academy of Sciences in the course of an experiment called "Tsarev 2", when a sample of a meteoric substance was heated in a vacuum. Then the release of gases such as H 2, CH 4, CO, H 2 O, N 2, etc. was recorded. Therefore, scientists rightly assumed that the chemical composition of the Earth's primary atmosphere included water and carbon dioxide, hydrogen fluoride vapor (HF), carbon monoxide gas (CO), hydrogen sulfide (H 2 S), nitrogen compounds, hydrogen, methane (CH 4), ammonia vapor (NH 3), argon, etc. Water vapor from the primary atmosphere participated in the formation of the hydrosphere, carbon dioxide turned out to be more in a bound state in organic matter and rocks, nitrogen passed into the composition of modern air, as well as again into sedimentary rocks and organic matter.

The composition of the Earth's primary atmosphere would not allow modern people to be in it without breathing apparatus, since there was no oxygen in the required quantities then. This element appeared in significant amounts one and a half billion years ago, as is believed, in connection with the development of the process of photosynthesis in blue-green and other algae, which are the oldest inhabitants of our planet.

Oxygen minimum

The fact that the composition of the Earth's atmosphere was initially almost anoxic is indicated by the fact that easily oxidized, but not oxidized graphite (carbon) is found in the most ancient (Katarchean) rocks. Subsequently, the so-called banded iron ores appeared, which included interlayers of enriched iron oxides, which means the appearance on the planet of a powerful source of oxygen in molecular form. But these elements came across only periodically (perhaps the same algae or other oxygen producers appeared as small islands in an anoxic desert), while the rest of the world was anaerobic. The latter is supported by the fact that easily oxidizable pyrite was found in the form of pebbles processed by the flow without traces of chemical reactions. Since flowing waters cannot be poorly aerated, the view has evolved that the pre-Cambrian atmosphere contained less than one percent oxygen of today's composition.

Revolutionary change in air composition

Approximately in the middle of the Proterozoic (1.8 billion years ago), the “oxygen revolution” took place, when the world switched to aerobic respiration, during which 38 can be obtained from one nutrient molecule (glucose), and not two (as with anaerobic respiration) units of energy. The composition of the Earth's atmosphere, in terms of oxygen, began to exceed one percent of the modern one, and an ozone layer began to appear, protecting organisms from radiation. It was from her that “hidden” under thick shells, for example, such ancient animals as trilobites. From then until our time, the content of the main "respiratory" element has gradually and slowly increased, providing a variety of development of life forms on the planet.

The gas composition of atmospheric air is one of the most important indicators of the state of the natural environment. The content of the main gases near the Earth's surface as a percentage is:

nitrogen - 78.09%,

oxygen - 20.95%,

water vapor - 1.6%,

argon - 0.93%,

· carbon dioxide - 0.04% (data are given based on normal conditions tº=25 ºC, P=760 mm Hg).

Nitrogen- gas, which is the main component of air. At normal atmospheric pressure and low temperatures, nitrogen is inert. The dissociation of nitrogen molecules and their decay into atomic nitrogen occurs at altitudes above 200 km.

Oxygen- produced by plants in the process of photosynthesis (about 100 billion tons annually). In the course of chemical evolution, one of the earliest major changes was the transition from a reducing atmosphere to an oxidizing one, in which the biological systems that characterize today's life on Earth began to develop. It has been established that with a decrease in the proportion of oxygen in the composition of the air to 16%, the main natural processes - respiration, combustion, and decay - will stop.

Carbon dioxide(carbon dioxide) enters the air as a result of the processes of fuel combustion, respiration, decay and decomposition of organic matter. There is no significant accumulation of carbon dioxide in the atmosphere, since it is absorbed by plants during photosynthesis.

In addition, the air always contains: neon, helium, methane, krypton, nitrogen oxides, xenon, hydrogen. But these components are contained in amounts not exceeding thousandths of a percent. This composition of atmospheric air can be considered characteristic of modern absolutely clean air. However, he never does.

Many impurities that enter the atmospheric air from various natural and artificial sources in different parts of the Earth with a time-varying intensity make up its non-permanent impurities, which can be conventionally called pollution .

Among the natural pollution factors are :

a) extraterrestrial air pollution by cosmic dust and cosmic radiation;

b) terrestrial pollution of the atmosphere during volcanic eruptions, weathering of rocks, dust storms, forest fires arising from lightning strikes, and the removal of sea salts.

Conventionally, the natural pollution of the atmosphere is divided into continental and marine, as well as inorganic and organic.

One of the most constantly present impurities in the atmospheric air is suspended particles. They can be both mineral and organic, a significant part of which is pollen and plant spores, fungal spores, microorganisms. Often, dust is formed by the smallest particles of soil and, in addition to minerals, contains a certain amount of organic matter.

With the smoke of forest fires, soot particles, that is, carbon, and products of incomplete combustion of wood, that is, various organic substances, including many phenolic compounds with mutagenic and carcinogenic properties, enter the air.

Volcanic dust and ash contain a certain amount of soluble salts of potassium, calcium, magnesium and other substances important for the mineral nutrition of plants. Oxides of sulfur, nitrogen, carbon, and chlorine enter the atmosphere with volcanic gases. Carbon dioxide enters the atmospheric carbon reserve, nitrogen and sulfur oxides are quickly washed out by rains and enter the soil in the form of weak acid solutions.

Atmospheric air is in constant interaction and metabolism with the Earth's stone shell - the lithosphere and the water shell - the hydrosphere. The role of the atmosphere in the circulation of substances that determine life on our planet is very great. The water cycle passes through the atmosphere. Volcanic ash carried by the winds enriches the soil with elements of mineral plant nutrition. Carbon dioxide emitted by volcanoes, entering the atmosphere, is included in the carbon cycle and absorbed by plants.

Natural sources of atmospheric impurities have always existed. The ways of removal from the air for different impurities can be different: dust precipitation, leaching with precipitation, absorption by plants or water surface, and others. There is a natural balance between the entry of impurities into the atmosphere and its self-cleaning, as a result of which for any substance that is part of the impurities, you can specify the natural limits of its content in the air, which is called background.

Air is an essential condition for the life of the overwhelming number of organisms on our planet.

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

Research History

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

For a long time it was believed that air is a single substance, not a mixture of gases. The heterogeneity hypothesis appeared in the scientific works of many scientists at different times. But no one has gone further than theoretical conjectures. Only in the eighteenth century, the Scottish chemist Joseph Black experimentally proved that the gas composition of air is not uniform. The discovery was made in the course of regular experiments.

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

The composition differs depending on the place of concentration. Determination of the composition of the air occurs constantly. The health of the people depends on it. Air is a mixture of what gases?

At higher elevations (especially in the mountains) there is a low oxygen content. 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 the 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. Installation up to ten bar is installed at any tire fitting station. Tires are inflated with air.
Workers use jackhammers, 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.
In car washes, the compressed air mass helps in quick drying of cars;
Manufacturing plants use compressed air to clean tools from any kind of contamination. In this way, whole hangars can be cleaned of chips 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;
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, thereby promoting oxidation processes. Thanks to this, the body receives the most important energy for life.

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

Air is a mixture of what gases? Let's consider them in more detail.

Nitrogen

Air is a mixture of gases, the first of which is nitrogen. The seventh element of the periodic system of Dmitri Mendeleev. The Scottish chemist Daniel Rutherford in 1772 is considered the discoverer.

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

In the composition of the air, its content is more than seventy-eight percent.

Under normal conditions, it is colorless and odorless. Does not enter into compounds with other chemical elements.

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

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

In cosmetology, gas is used to treat acne, scars, warts, and the body's thermoregulation system.

With the use of nitrogen, ammonia is synthesized, nitric acid is produced.

In the chemical industry, oxygen is used to oxidize hydrocarbons to alcohols, acids, aldehydes, and to produce nitric acid.

Fishing industry - oxygenation of reservoirs.

But the most important gas is for living beings. With the help of oxygen, the body can utilize (oxidize) the necessary proteins, fats and carbohydrates, turning 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 and smell. The eighteenth element of the periodic system.

The first mention is attributed to an English chemist in 1785. And Lord Laray 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 the panes in plastic windows;
protective environment during welding;
fire extinguishing agent;
for air purification;
chemical synthesis.

It doesn't do much good for the human body. At high concentrations of gas leads to asphyxiation.

Cylinders with argon gray or black.

The remaining seven elements make up 0.03% in air.

Carbon dioxide

Carbon dioxide in air is colorless and odorless.

It is formed as a result of decay or combustion of organic materials, it is released during breathing and the operation of cars and other vehicles.

In the human body, it is formed in tissues due to vital processes and is transferred through the venous system to the lungs.

It has a positive meaning, because under load, it expands the capillaries, which provides the possibility of greater transport of substances. Positive effect on the myocardium. It helps to increase the frequency and strength of the load. Used in the correction of hypoxia. Participates in the regulation of respiration.

In industry, carbon dioxide is obtained from combustion products, as a by-product of chemical processes or in the separation of air.

The 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 cartridges for gas weapons;
coolant.

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.

It has high electrical conductivity. It has a complete electron shell. Inert.

Gas is obtained by separation of air.

Application:

Inert environment in industry;
Refrigerant in cryogenic installations;
Filler for gas discharge lamps. Has found wide application thanks to advertising. Most of the colored signs are made with neon. When an electric discharge is passed, the lamps give a bright colored glow.
Signal lights at beacons and airfields. Worked well in heavy fog.
Air mixture element for people working with high pressure.

Helium

Helium is a monatomic gas, colorless and odorless.

Application:

Like neon, when an electric discharge is passed through, it gives a bright light.
In industry - to remove impurities from steel during smelting;
Coolant.
Filling airships and balloons;
Partially in breathing mixes for deep dives.
Coolant in nuclear reactors.
The main children's joy is flying balloons.

For living organisms, it is of no particular benefit. In high concentrations, it can cause poisoning.

Methane

Air is a mixture of gases, the seventh of which is methane. The gas is colorless and odorless. Explosive in high concentrations. Therefore, for indication, odorants are added to it.

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

Home stoves, boilers, gas water heaters work mainly on methane.

The product of the vital activity of microorganisms.

Krypton

Krypton is an inert monatomic gas, colorless and odorless.

Application:

in the production of lasers;
propellant oxidizer;
filling incandescent lamps.

The effect on the human body has been studied little. Applications for deep-sea diving are being studied.

Hydrogen

Hydrogen is a colorless combustible gas.

Application:

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

Xenon

Xenon is a monatomic colorless gas.

Application:

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

Harmless to the human body. Doesn't offer much benefit.

The composition of the air on earth is one of the reasons for our life. Without air, a person will live only three minutes, and after 10 clinical death will occur.

While we breathe, we live. No other planet in the solar system has such a close relationship between chemistry and biology. Our world is unique.

Depending on the territory, the volume of the main component of the vital gas is from 16 to 20 percent - this is oxygen, the formula of which is O 2. Its variation is felt in space as "freshness" after a thunderstorm - this is ozone O 3.

From this article you will learn all the secrets of the air shell of the earth. What will happen to the world without one component? What harm can it do? How will a slight deterioration in the atmosphere affect life?

What is air

The ancient Greeks used two words as a definition for air: calamus, which meant the lower layers of the atmosphere (Dim), and ether meant the bright upper layers of the atmosphere (transcendental space).

In alchemy, the symbol for air is a triangle divided in two by a horizontal line.

In the modern world, such a definition would suit him - a gas mixture that surrounds the planet, which protects against the penetration of solar radiation and large doses of ultraviolet radiation.

Over a multimillion-year period of development, the planet has transformed gaseous substances and created a unique protective shield, which is almost impossible to see. Their mass fraction is incommensurably small for space.

Nothing else has an impact on the formation of the world. If we remember that part of the air masses is oxygen, then what will happen on earth without it? Buildings and structures will collapse.

Metal bridges and other structures that fascinate millions of tourists will turn into a single lump due to the small number of oxygen molecules (in this situation, close to zero). The life of all living organisms on the planet will worsen, and some will lead to death.

Seas and oceans, evaporating in the form of hydrogen, will disappear. And when the planet becomes like the moon, a radiation fire will reign, burning out the remains of the flora, because without oxygen the temperature will increase very much, but without the atmosphere there will be no protection from the sun.

What is air made of

Almost the entire earth's atmosphere consists of only five gases: nitrogen, oxygen, water vapor, argon and carbon dioxide.

Other mixtures are also present in it, but for the sake of clarity of presentation, the chemical composition of water vapor will not be considered. It is worth mentioning that in the air mass it occupies no more than five percent.

Composition of air in percent

Ideally, the air collected in a jar consists of:

78 percent from nitrogen;
16 - 20 percent oxygen;
1 percent argon;
three hundredths of a percent of carbon dioxide;
one thousandth of a percent of neon;
0.0002 percent methane.

The smaller components are:

helium - 0.000524%;
krypton - 0.000114%;
hydrogen - H2 0.00005%;
xenon - 0.0000087%;
ozone O 3 - 0.000007%;
nitrogen dioxide - 0.000002%;
iodine - 0.000001%;
carbon monoxide;
ammonia.

Composition of inhaled and exhaled air

Breathing takes precedence over other human needs. From the school course, everyone knows that a person inhales oxygen and exhales carbon dioxide. Although in life, in addition to pure O 2, other substances are present in the air.

Inhale - exhale. A similar cycle is repeated about 22,000 times a day, during which oxygen is consumed, which maintains the vitality of the human body. The problem is that delicate lung tissue is attacked by air pollution, cleaning solutions, fibers, fumes and dust.

The first half of the article talked about reducing oxygen, but what will happen with an increase. Doubling the concentration of the main gas would lead to a reduction in fuel consumption in cars.

By inhaling more oxygen, a person would become much more psychologically positive. However, for some insects, a favorable climate would allow them to increase in size. There are a number of theories that predict this. It seems that no one would like to meet a spider the size of a dog, and one can only fantasize about the growth of large representatives.

By inhaling less heavy metals, humanity could defeat a number of complex diseases, but such a project will require a lot of effort. There is a whole program aimed at creating a practical paradise on earth: in every house, room, city or country. Its goal is to make the atmosphere cleaner, to save people from dangerous work in mines and metallurgy. A place where jobs would be occupied by masters of their craft.

It is important that it is possible to inhale clean, untouched by industry air, but this requires political, or better, world will. In the meantime, people are busy looking for money and cheap (dirty) technologies, only city smog remains to be inhaled. How long this will last is unknown.

A map will allow you to visually assess the atmospheric air of the capital of our country, which is inhaled by more than a dozen people.

Hygienic value of atmospheric air

Officially, air pollution can be defined as the content of harmful substances in the air or particles or microscopic biological molecules that pose a health hazard to living organisms: humans, animals or plants.

The level of air pollution in a particular location depends mainly on the source or sources of pollution. This includes:

vehicle exhaust gases;
coal power plants;
industrial plants and other sources of pollution.

All of the above spews various types of hazardous substances and toxins into the air, exceeding the norm by tens, and sometimes hundreds of times. In combination with natural sources - volcanoes, geysers, etc. - a deadly cocktail of poisonous air masses is created, which is commonly called "smog".

The evidence of each person's guilt is clear. Our personal choices and industry can have a detrimental effect on much-needed gas. For a century of technological breakthrough, nature has managed to suffer, which means revenge is inevitable.

By increasing emissions, humanity is approaching the abyss, from which there is no return and cannot be. Before it's too late, at least something should be corrected. It has been proven that alternative industrial technologies can help clean the air in Moscow, St. Petersburg, Tokyo, Berlin and any other major city.

Here are some solutions:

Replace gasoline with electricity in cars, and the sky above the city will become a little more beautiful.
Remove coal stations from cities, let them go down in the history of the country, start using the energy of the sun, water, and wind. Then, after the rain, soot will not fly from the chimney of the next plant, but there will be only the smell of “freshness”.
Plant a tree in the park. If thousands do this, then asthmatics and depressed people will stop visiting hospitals in search of a unique recipe from the lips of a psychologist.