Oxygen content in atmospheric air. What gases consists of air

The main components of atmospheric air are oxygen (about 21%), nitrogen (78%), carbon dioxide (0.03-0.04%), water vapors, inert gases, ozone, hydrogen peroxide (about 1%).

Oxygen is the most composite part of the air. With its direct participation, all oxidative processes in the human body and animals proceed. Alone consumes about 350 ml of oxygen per minute, and with severe physical work, the amount of oxygen consumed increases several times.

Inhaled air contains 20.7-20.9% oxygen, and exhaled - about 15-16%. Thus, the tissues of the body absorb about 1/4 oxygen existing in the composition of the inhaled air.

In the atmosphere, the oxygen content does not significantly change. Plants absorb carbon dioxide and, breaking it, absorb carbon, and the freed oxygen is distinguished into the atmosphere. The source of oxygen formation is also a photochemical decomposition of water vapor in the upper layers of the atmosphere under the influence of the ultraviolet radiation of the Sun. In ensuring a permanent composition of atmospheric air, mixing of air flows in lower layers Atmosphere. The exclusion is a hermetically closed premises, where, due to the long stay of people, the oxygen content can significantly decrease (submarines, asylum, sealed cabins, etc.).

For the body, the partial pressure * of oxygen is essential, and not its absolute content in the inhaled air. This is due to the fact that the transition of oxygen from alveolar air into the blood and from the blood to the tissue fluid occurs under the influence of the difference in partial pressure. The partial oxygen pressure decreases with an increase in the height of the terrain above sea level, (Table 1).

Table 1. Partial oxygen pressure at different heights

Great importance It has the use of oxygen for the treatment of diseases accompanied by oxygen starvation (oxygen tents, inhalers).

Carbon dioxide. The content of carbon dioxide in the atmosphere is constantly constant. This constancy is explained by the circulation in nature. Despite the fact that the processes of rotting, the livelihoods of the body are accompanied by the release of carbon dioxide, a significant increase in its content in the atmosphere does not occur, since carbon dioxide is absorbed by plants. At the same time, carbon goes to the construction of organic substances, and oxygen enters the atmosphere. In the exhaled air contains up to 4.4% carbon dioxide.

Carbon dioxide is the physiological causative agent of the respiratory center, therefore, with an artificial respiration, it is added to air in minor quantities. In large quantities, it can have a narcotic effect and cause death.

Carbon dioxide has and hygienic value. According to its content, judge the purity of the air of residential and public premises (i.e. the premises where people are). With the accumulation of people in poor ventilated rooms, in parallel with the accumulation of carbon dioxide in the air, the content of other human life products increases, the air temperature increases and its humidity increases.

It has been established that if the content of carbon dioxide in the air of the rooms exceeds 0.07-0.1%, the air acquires an unpleasant smell and can disrupt the functional state of the body.

The parallelism of the change in the listed properties of air of residential premises and the increase in the concentration of carbon dioxide, as well as the simplicity of determining its contents allow you to use this indicator for hygienic assessment Air quality and ventilation efficiency of public spaces.

Nitrogen and other gases. Nitrogen is the main component of atmospheric air. In the body, it is in a dissolved state in the blood and tissue fluids, but does not participate in chemical reactions.

Currently, it is experimentally established that under conditions of increased pressure of air nitrogen causes non-muscular coordination disorder in animals, the subsequent excitement and a narcotic state. Similar phenomena researchers observed divers. The use for the respiration of the divers of the helium-oxygen mixture allows you to increase the depth of descent to 200 m without pronounced symptoms of intoxication.

With electrical thundering discharges and under the influence of ultraviolet rays of the Sun in the air, a small number of other gases is formed. The hygienic value is relatively small.

* The partial pressure of the gas in the mixture of gases is called the pressure that this gas would produce if he occupied the entire volume of the mixture.

The chemical composition of the air has an important hygienic value, since it plays a decisive role in the implementation of the body's respiratory function. The atmospheric air is a mixture of oxygen, carbon dioxide, argon and other gases in the ratios shown in Table. one.

Oxygen(O2) - the most important component of the air for humans. In a state of rest, a person usually absorbs on average 0.3 liters of oxygen in 1 min.

In physical activity, oxygen consumption increases sharply and can reach 4.5 / 5 l and more than 1 min. The oscillations of the oxygen content in the atmospheric air are small and not exceed, as a rule, 0.5%.

In residential, social and sports premises, significant changes in the oxygen content is observed, since the outer air penetrates. Under the most adverse hygienic conditions in the room there was a decrease in the oxygen content by 1%. Such oscillations do not have a noticeable influence on the body.

Typically, physiological shifts are observed by reducing the oxygen content to 16-17%. If its content decreases to 11 -13% (when lifting height), pronounced oxygen deficiency appear, sharp deterioration of well-being and reduced operations. The oxygen content of up to 7-8% may result in death.

In sports practice, in order to improve the efficiency and intensity of reducing processes is used inhalation of oxygen.

Carbon dioxide(CO2), or carbon dioxide, - colorless gas without smell, formed by the breath of people and animals, rotting and decomposition of organic substances, fuel combustion, etc. in atmospheric air outside settlements The carbon dioxide content is on average 0.04%, and in industrial centers its concentration rises to 0.05-0.06%. In residential and public buildings, while in them a large number of people, carbon dioxide can increase to 0.6-0.8%. With the worst hygienic conditions in the room (a large cluster of people, poor ventilation, etc.) its concentration usually does not exceed 1% due to the penetration of the outer air. Such concentrations do not cause negative phenomena in the body.

With prolonged inhalation of air with a content of 1 - 1.5% carbon dioxide, a deterioration of well-being is observed, and pathological shifts are detected at 2-2.5%. Significant violations of the functions of the body and a decrease in performance occur when the content of carbon dioxide is 4-5%. The content of 8-10% is loss of consciousness and death. A significant increase in carbon dioxide in the air may occur during emergency situations in closed spaces (mines, mines, submarines, bomb-shelter IDR) or in those places where there is an intensive decomposition of organic substances.

Determination of carbon dioxide content in residential, public and sports facilities can serve indirect indicator Air pollution by products of people's vital activity. As already noted, carbon dioxide itself in these cases does not harm the body, but together with an increase in its content there is a deterioration in physical and chemical properties air (the temperature and humidity increases, the ion composition is broken, the smelling gases appear). The air indoors is considered poorly, if the carbon dioxide content in it exceeds 0.1%. This value is accepted as calculated when designing and ventilated ventilation.

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Chemical composition of air It is important in the implementation of the respiratory function. The atmospheric air is a mixture of gases: oxygen, carbon dioxide, argon, nitrogen, neon, crypton, xenon, hydrogen, ozone and others. Oxygen is most important. Along the man absorbs 0.3 l / min. In physical activity, oxygen consumption increases and can reach 4.5 -8 l / min oscillation of the oxygen content in the atmosphere is small and not exceed 0.5%. If the oxygen content decreases to 11-13%, the phenomena of oxygen deficiency appear.

The oxygen content of 7-8% can lead to death. Carbon dioxide - without color and smell, formed when breathing and rotting, combustion of fuel. The atmosphere is 0.04%, and in the industries - 0.05-0.06%. With a large cluster of people, up to 0.6 - 0.8% may increase. With prolonged inhalation of air with a content of 1-1.5% of carbon dioxide, a deterioration of well-being is observed, and at 2-2.5% - pathological shifts. At 8-10% of the loss of consciousness and death, the air has a pressure called atmospheric or barometric. It is measured in millimeters of mercury pillar (mm.rt.st.), hectopascals (GPA), millibares (MB). Normal is considered to be the pressure of the atmosphere at sea level on the breadth of 45˚ at air temperature 0 ° C. It is 760 mm.rt. (The air indoor is considered poorly quality if it contains 1% carbon dioxide. This value is accepted as calculated when designing and device ventilation in rooms.

Air pollution. Carbon oxide - gas without color and smell, formed in case of incomplete combustion of fuel and enters the atmosphere with industrial furnaces and exhaust gases of internal combustion engines. In the megalopolis, its concentration can reach up to 50-200mg / m3. When smoking tobacco, carbon monoxide enters the body. Carbon monoxide - blood and general oxygen poison. It blocks hemoglobin, it loses the ability to carry oxygen to the tissues. Acute poisoning occurs at the concentration of carbon monoxide in the air in 200-500 mg / m3. At the same time, there is a headache, general weakness, nausea, vomiting. Maximum permissible concentration of average daily 0 1 mg / m3, one-time - 6 mg / m3. Air can contaminate sulfur gas, soot, resinous substances, nitrogen oxides, carbon black.

Microorganisms. In small quantities are always in the air, where they are entered with soil dust. Fingering microbes of infectious diseases quickly die. A special danger in epidency is air of residential premises and sports grounds. For example, in the wrestling halls there is a microbial content of up to 26,000 in 1m3 air. Aerogenic infections in such air are very quickly distributed.

Dust It is a light dense particles of mineral or organic origin, falling into light dust, there is delayed and causes various diseases. Production dust (lead, chrome) can cause poisoning. In cities, dust should not exceed 0.15 mg / m3. Sports are needed to regularly water, have a green zone, carry out wet cleaning. For all enterprises polluting the atmosphere, sanitary protection zones are installed. In accordance with the class of harm, they have different sizes: for class 1 enterprises - 1000 m, 2 - 500 m, 3 - 300 m, 4 -100 m, 5 - 50 m. When placing sports near enterprises, it is necessary to take into account the wind rose, sanitation Protective zones, degree of air basement, etc.

One of the important measures to protect aerial There are preventive and current sanitary supervision and systematic control of the state of atmospheric air. It is made using an automated monitoring system.

Clean atmospheric air at the surface of the Earth has the following chemical composition: oxygen - 20.93%, carbon dioxide - 0.03-0.04%, nitrogen - 78.1%, argon, helium, crypton 1%.

In the exhaled oxygen air by 25% less, and carbon dioxide is 100 times more.
Oxygen. The most important component of the air. It provides the course of redox processes in the body. An adult man in peace consumes 12 liters of oxygen, with physical work 10 times more. In blood oxygen is due to hemoglobin.

Ozone. Chemically unstable gas is capable of absorbing solar short-wave ultraviolet radiation, which is destructively acting on all alive. Ozone absorbs long-wave infrared radiation emanating from the Earth, and thus prevents its excessive cooling (ozone layer of the Earth). Under the influence of UVO, ozone decomposes on a molecule and an oxygen atom. Ozone is a bactericidal tool when disinfecting water. In nature, it is formed during electrical discharges, in the process of evaporation of water, with UFO, during a thunderstorm, in the mountains and in coniferous forests.

Carbon dioxide. It is formed as a result of redox processes occurring in the body of people and animals, combustion of fuel, rotting organic substances. In the air of cities, the concentration of carbon dioxide is increased due to industrial emissions - up to 0.045%, in residential premises - to 0.6-0.85. An adult man in peace highlights 22 liters of carbon dioxide per hour, and in physical work - 2-3 times more. Signs of deterioration of well-being in humans appear only with long inhalation of air containing 1-1.5% carbon dioxide, pronounced functional changes - at a concentration of 2-2.5% and sharply pronounced symptoms (headache, general weakness, shortness of breath, heartbeat, decrease performance) - at 3-4%. The hygienic value of carbon dioxide is that it serves as an indirect indicator of overall air pollution. The rate of carbon dioxide in the gym - 0.1%.

Nitrogen. Indincher gas serves as a diluent of other gases. Increased nitrogen inhalation can have a narcotic effect.

Carbon monoxide. It is formed with incomplete combustion of organic substances. Does not possess a color or smell. The concentration in the atmosphere depends on the intensity of the automotive movement. Penetrating through the pulmonary alveoli into the blood, it forms carboxygemoglobin, as a result of hemoglobin loses the ability to carry oxygen. The maximum permissible average daily concentration of carbon monoxide is 1 mg / m3. Toxic doses of carbon monoxide in the air are 0.25-0.5 mg / l. With prolonged exposure, headache, fainting, heartbeat.

Sulphur dioxide. It enters the atmosphere as a result of burning fuel rich in gray (stone coal). It is formed when firing and melting sulfur ores, with tissue dye. It annoys the mucous eye and an END. Threshold of sensation 0.002-0.003mg / l. Gas is harmful to vegetation, especially the coniferous species of trees.
Mechanical air impurities Compared in the form of smoke, soot, soot, chopped soil particles and other solids. The dustiness of air depends on the nature of the soil (sand, clay, asphalt), its sanitary condition (watering, cleaning), from the contamination of the atmosphere by industrial emissions, the sanitary condition of the premises.

Dust mechanically irritates the mucous membranes of the DPI and the eye. Systematic inhalation of dust causes diseases of the respiratory organs. When breathing through the nose is delayed up to 40-50% of dust. Microscopic dust, long in suspended state, is most unfavorable in hygienic terms. Electricity dust enhances its ability to penetrate into the lungs and linger in them. Dust. Containing lead, arsenic, chrome, etc. Poisonous substances cause typical phenomena of poisoning, and with penetration not only when inhaled, but also through the skin and the HCR. In the dusty air, the intensity of solar radiation and air ionization is significantly reduced. To prevent the adverse effects of dust on the body, residential buildings are located to air pollutants from the windward side. Sanitary zones are arranged between them with a width of 50-1000 m and more. In residential premises, systematic wet cleaning, ventilation of the premises, shifting shoes and outerwear, the use of non-dusting soils and watering.

Air microorganisms. Bacterial air pollution, like other objects external environment (Water, soil), represents the danger in the epidemiological terms. There are various microorganisms in the air: bacteria, viruses, mold fungi, yeast cells. The most common is an air-drip method of transmitting infections: a large number of microbes come into the air, with breathing people entering the respiratory paths of healthy people. For example, with a loud conversation, and those more when coughing and sneezed, the smallest droplets are sprayed at a distance of 1-1.5 m and with air apply to 8-9 m. These droplets can be in suspended state of 4-5 hours, but in most cases settle in 40-60 minutes. In dust, the influenza virus and diphtheria sticks retain the viability of 120-150 days. There is a known relationship: the more dust in the air of the premises, the more abundant in it the content of microflora.

Chemical composition of air

Air is a mixture of gases forming a protective layer around the Earth - the atmosphere. Air is needed to all living organisms: animals for breathing, and plants - for nutrition. In addition, the air protects the Earth from the destructive ultraviolet radiation of the Sun. The main components of the air - nitrogen and oxygen. There are also small impurities of noble gases, carbon dioxide and a certain amount of solid particles - soot, dust. The air is needed by all animals for breathing. About 21% of air is oxygen. Oxygen molecule (O2) consists of two connected oxygen atoms.

The composition of the air

The percentage of various heating in the air is slightly changed depending on the place, time of year and day. Nitrogen and oxygen - the main air components. One percent of air is noble gases, carbon dioxide, water vapor and contamination, such as nitrogen dioxide. Gaza air can be divided by fractional distillation. The air is cooled until the gases proceed to the liquid state (see article " Solid body, liquids and gases "). Poshy this liquid mixture is heated. The boiling point of each liquid is its own, and the gase-generated gases can be assembled from-sensible. Oxygen, nitrogen and carbon dioxide are constantly falling out of the air into living organisms and return to the air, i.e. There is a circulation. Animals inhale air oxygen and exhale carbon dioxide.

Oxygen

Oxygen is necessary for life. Animals breathe them, with his help they absorb food and get energy. Day in plants process photosynthesis, and plants isolated oxygen. Oxygen is also necessary for combustion; Without oxygen, nothing can burn. Almost 50% of compounds in the earth's crust and the world ocean contain oxygen. Conventional sand is a compound of silicon with oxygen. Oxygen is used in the respiratory devices of divers and in hospitals. Oxygen is also used in the production of steel (see Article "Iron, Steel and Other Materials") and rocket technology (see the article "Rockets and Spacecraft").

In the upper layers of the atmosphere, oxygen atoms are connected by three, forming ozone molecule (O3). Ozone - It is an allotropic oxygen modification. Ozone is a poisonous gas, but in the ozone layer atmosphere protects our planet, absorbing most of the harmful ultraviolet radiation of the Sun (more in the article "The Impact of the Sun on Earth").

Nitrogen

More than 78% of air is nitrogen. Bel-ki, from which living organs are built, also contain nitrogen. The main industrial application of nitrogen - ammonia productionnecessary for fertilizer. Nitrogen is connected to hydrogen for this. Nitrogen is pumped in packing for meat or fish, because When contacting with ordinary air, products are oxidized and deteriorated by transplanting human organs are stored in liquid nitrogen, because it is cold and chemically inert. Nitrogen molecule (N2) consists of two connected nitrogen atoms.

Plants receive nitrogen from the soil in the form of nitrates and use its day synthesis proteins. Animals eat plants, and nitrogen compounds are returned to the soil with the secretions of animals, as well as the decomposition of their dead tel. In the soil, nitrogen compounds are decomposed with bacteria with the release of ammonia, and then free nitrogen. Other bacteria absorb nitrogen from the air and convert to nitrates digested by plants.

Carbon dioxide

Carbon dioxide is a compound of carbon and oxygen. The air contains about 0.003% of carbon dioxide. The carbon dioxide molecule (CO2) consists of two oxygen atoms and one carbon atom. Carbon dioxide is one of the elements of the carbon cycle. Plants absorb it at photosynthesis, and animals exhale it. Carbon dioxide is also formed during the combustion of substances containing carbon, such as wood or gasoline. Because our cars and plants burn a lot of fuel, the share of carbon dioxide in the atmosphere grows. Most substances cannot be lit in the corner-acid gas, so it is used in fire extinguishers. Carbon dioxide is denser. He "shakes" the flame, overlapping the access of oxygen. Carbon dioxide slightly dissolves in water, forming a weak solution of coalic acid. Solid carbon dioxide is called dry ice. When melting, dry ice turns into gas; It is used to create artificial clouds in the theater.

Air pollution

Sauce and poisonous gases are carbon monoxide, nitrogen dioxide, sulfur dioxide - contaminate the atmosphere. Durchable gas is formed under the go-rhenium. Many substances are burning so quickly that they do not have time to attach the sufficient oxygen and instead of carbon dioxide (CO2) forms a ditch gas (CO). Carbon black gas is very poisonous; It interferes with the blood of animals to carry oxygen. In the carbon monoxide molecule, only one oxygen atom. Car exhaust gases contain carbon monoxide, as well as nitrogen dioxide causing acid rains. Sulfur dioxide is released during the combustion of fossil fuels, especially coal. He is poisonous and makes it difficult to breathe. In addition, it dissolves in water and serves as the cause of acid rain. Dust and Co-Poti particles that emitted into the atmosphere of enterprises are also contaminated by the WHO; We inhale them, they are setting on plants. Lead (though, this hour, many cars operate on gasoline without lead are added to gasoline for better combustion. Lead compounds accumulate in the body and adversely affect the nervous system. In children, they can cause brain disorders.

Acid rain

In rainwater, it is always contained a little acids due to dissolved carbon-acid gas, but pollutants (sulfur and nitrogen dioxides) increase the acidity of rain. Acid rains cause corrosion of metals, corrosive stone structures and increase the acidity of fresh water.

Noble gases

Noble gases are 6 elements of the 8th group of the periodic table. They are extremely inert chemically. Only they exist in the form of outlit atoms that do not form molecules. Because of their passivity, some of them fill the lamps. Xenon is practically not used by man, but the argon is pumped into the electric bulb, and the crip-tone fill fluorescent lamps. Neon flashes with red-orange light when the electric discharge is passed. It is used in sodium street lamps and neon lamps. Radon radioactive. It is formed as a result of the decay of the radium metal. No compounds of helium science are unknown, and helium is considered absolutely inert. Its density is 7 times less than the density of air, so they fill the airships. Filled helium balloons Equipped with scientific equipment and launched into the upper layers of the atmosphere.

Greenhouse effect

So called now the increase in carbon dioxide in the atmosphere and caused by this global warming. Raising average annual temperatures around the world. Carbon dioxide does not give heat to leave the Earth, as well as glass retains a high temperature inside the greenhouse. Since carbon dioxide in the air is becoming more and more, more and more heat is delayed in the atmosphere. Even a small warming causes an increase in the world's ocean, the change of winds and the melting of the part of the ice in the poles. Scientists believe that if the content of carbon dioxide will grow as fast, then in 50 years the average tempera may increase by 1.5 ° C to 4 ° C.

air is a mixture of gases, and it means items. . Nitrogen, oxygen, carbon dioxide. In cities and other gases ...

The percentage of gases.

need to graphic image Air molecules?

Air in Chemistry-No2

zit Hein. Allah Akbar. Tabier. foreign words who are forbidden to speak. what it is - xs

If you think the air has its own separate formula - you are mistaken, it is not denoted in chemistry.

Air is a natural mixture of gases, mainly nitrogen and oxygen, which is an earth's atmosphere. Air composition: nitrogen N2 oxygen O2 Argon Ar Carbon dioxide CO2 Neon Neon NE Methane CH4 helium He Kripton Kr Hydrogen H2 xenon XE Water H2O In addition, air always contains water pairs. So, at a temperature of 0 ° C 1 m³ of air, the maximum 5 grams of water can accommodate, and at a temperature of +10 ° C - already 10 grams. In alchemy, the air is denoted in the form of a triangle with a horizontal feature.

nitrogen

the main component inhale. air

Alternative descriptions

Metal fragile gas

Gas from which air consists of 78%

Chief "Air Fill"

The main component of the air inhaled by you, which can not breathe in pure form

Air component

Air fertilizer

Chemical element - the basis of a number of fertilizers

Chemical element, one of the main nutrients of plants

Chemical element, component of air

Nitrogenium

Liquid refrigerant

Chemical element, gas

Magic sword Paracelsa

In Latin, this gas is called "Nitrogenium", that is, "Horitant Selitra"

The name of this gas occurred from the Latin word "lifeless"

This gas - the component of the air was practically absent in the primary atmosphere of the Earth 4.5 billion years ago

Gas whose liquid serves to cool ultra-mechanical appliances

What gas in liquid state is stored in the Dewar vessel?

Gas, frozen terminator II

Gas-cooler

What gas carries fire?

The most common element in the atmosphere

The basis of all nitrates

Chemical element, n

Freezing gas

Three-quarter air

As part of ammonia

Gas from the air

Gas at number 7

Element from Selitra

Main gas in the air

Popular gas

Element from nitrate

Vessel liquid gas

Gas number 1 in the atmosphere

Fertilizer in air

78% air

Gas for cryostat

Almost 80% air

The most popular gas

Common gas

Dewar vessel gas

The main component of the air

. "N" in the air

Nitrogen

Aerial component

Ancient rich philus city, with Dagon temple

Most of the atmosphere

Prevails in the air

Following carbon in the table

Between carbon and oxygen in the table

7th from Mendeleev

Before oxygen

Oxygen predecessor in table

Harvest gas

. "Lifeless" among gases

Following the carbon in the table

Pat from Palindrome Feta

Gas - Component Fertilizers

To oxygen in the table

After carbon in the table

78.09% air

What gas is more in the atmosphere?

What gas hovers in the air?

Most of the atmosphere

Seventh in the ranks of chemical elements

element number 7.

Composite part of air

In the table it after carbon

Unquenchable part of the atmosphere

. "Horitant Selitra"

Zaku of this gas - "Universe Gas"

The basis of the earth's atmosphere

Most of the air

Part of air

Carbon successor in the table

Lifeless part of the air

Seventh in Mendeleevsk

Gas

Most air

Seventh chemical element

About 80% air

Gas from the table

Gas, significantly affecting the harvest

The main component of nitrates

The base of air

Main element of air

. "Non-livid" air element

Mendeleev appointed him seventh

Lion share of air

Seventh in Mendeleev Shero

Main gas in the air

Seventh in chemical

Main air gas

The main gas of the air

Between carbon and oxygen

Inert under normal dimensional gas

The most common gas on earth

Gas, main air component

Chemical element, gas without color and odor, main component of air, also included in proteins and nucleic acids

Name of chemical element

. "N" in the air

. "Lifeless" among gases

. "Non-livid" air element

. "Horitant Selitra"

7th Count Mendeleev

Most of the inhaled air

Included in the air

Gas - Component Fertilizers

Gas that significantly affects the harvest

The main composition. Part of air

The main part of the air

Main "Air Fill"

Zaku of this gas - "GAZ"

What gas is larger in the atmosphere

What gas in liquid state is stored in the Dewar vessel

Which gas is in the air

What gas exhaust fire

M. Chemich. the basis, the main element of the Selitra; Selitrocker, Selitrod, Selitryak; It is the main, by quantity, part of our air (nitrogen volumes, oxygen azoty, nitrogen, nitrogen, nitrogen containing. Chemists distinguish between these words or the degree of nitrogen content in combinations with other substances

In Latin, this gas is called "Nitrogenium", that is, "feeding Selitra"

The name of this gas occurred from the Latin word "lifeless"

In front of oxygen in the table

Carbon conversation in the table

Seventh Count Mendeleev

Chemical. Code name element 7

Chemical element

What a chemical element number 7

Part of the Selitra

Natural chemical composition of atmospheric air

By chemical composition, pure atmospheric air is a mixture of gases: oxygen, carbon dioxide, nitrogen, as well as a number of inert gases (argon, helium, crypton, etc.). Since the air is a physical mixture, and not chemical compound constituting its gases, then when lifting even tens of kilometers, percentage These gases practically does not change.

However, with a height, as a result of a decrease in the density of the atmosphere, concentrations and partial pressure of all gases in the air are reduced.

The surface of the earth in the atmospheric air contains:

oxygen - 20.93%;

nitrogen - 78.1%;

carbon dioxide - 0.03-0.04%;

inert gases - from 10-3 to 10-6%.

Oxygen (O2)- The most important part of the air. It is necessary for oxidative processes and is in the blood, mainly in associated condition - in the form of oxymemoglobin, which is transferred by erythrocytes to the cells of the body.

The transition of oxygen from alveolar air into blood due to the difference in partial pressure in the alveolar air and venous blood. By virtue of the same reason, oxygen is carried out from arterial blood into the interstitial fluid, and then in cells.

In nature, oxygen is consumed mainly on the oxidation of organic substances contained in air, water, soil and on combustion processes. The decrease of oxygen is replenished due to its large stocks in the atmosphere, as well as as a result of the activity of phytoplankton oceans and land plants. Continuous turbulent flow of air masses level the oxygen content in the surface layer of the atmosphere. Therefore, the oxygen level at the surface of the Earth varies slightly: from 20.7 to 20.95%. In residential premises, public buildings, the oxygen content is also practically not changed due to the light diffusion of it through the pores of the building materials, the slots in the windows, etc.

In the sealed premises (shelters, submarines, etc.) the oxygen content can significantly decrease. However, a pronounced deterioration of well-being, a decrease in performance in humans is observed with a very significant drop in the oxygen content - up to 15-17% (at a rate of almost 21%). It should be emphasized that in this case it is a reduced oxygen content under normal atmospheric pressure.

As an increase in air temperature to 35-40 ° C and high humidity, the partial pressure of oxygen is reduced, which can have a negative effect on patients with hypoxia phenomena.

In healthy people oxygen starvation Due to the decrease in the partial pressure of oxygen, it may be observed during flights (high-rise) and when climbing the mountains (mountain sickness, which starts at an altitude of about 3 km).

Heights of 7-8 km correspond to 8.5-7.5% oxygen in the sea level at sea level and for untangled people are considered incompatible with life without using oxygen devices.

The dosage increase in the partial pressure of oxygen in the air in the barocamera is used in surgery, therapy and emergency care.

Oxygen in pure form has a toxic effect. Thus, in animal experiments, it was shown that with pure oxygen respiration in animals, atelectases in the lungs are found in 1-2 hours, after 3-6 hours - a violation of the permeability of capillaries in the lungs, after 24 hours - phenomena of pulmonary edema.

Even faster, hyperoxia in an oxygen medium with high pressure develops - both the lesion of the lung tissue and the defeat of the central nervous system.

Carbon dioxide or carbon dioxide is in nature in free and related states. Up to 70% of carbon dioxide was dissolved in the water of the seas and oceans, the composition of some mineral compounds (limestone and dolomites) includes about 22% of the total amount of carbon dioxide. The rest of the number falls on the animal and vegetable world. In nature, continuous processes of isolation and absorption of carbon dioxide occur. It is released into the atmosphere as a result of the respiration of man and animals, as well as burning, rotting, fermentation. In addition, carbon dioxide is formed under industrial limestone and dolomites, it is possible to release it with volcanic gases. Along with the processes of education in nature, the processes of carbon dioxide assimilation are processes - active absorption by plants in the process of photosynthesis. From air carbon dioxide is washed with precipitation.

An important role in maintaining the constant concentration of carbon dioxide in atmospheric air plays its release from the surface of the seas and oceans. Carbon dioxide dissolved in the water of the seas and oceans is in dynamic equilibrium with air carbon dioxide and with an increase in partial pressure in the air dissolves in water, and with a decrease in partial pressure, it is released into the atmosphere. The processes of formation and assimilation are interrelated, due to this, the content of carbon dioxide in atmospheric air relatively constantly and is 0.03-0.04%. Per lately The concentration of carbon dioxide in the air of industrial cities increases as a result of intensive air pollution with fuel combustion products. The content of carbon dioxide in urban air may be higher than in a clean atmosphere, and up to 0.05% or more. Known the role of carbon dioxide in the creation of a "greenhouse effect", leading to an increase in the temperature of the surface air layer.

Carbon dioxide is a physiological causative agent of the respiratory center. Its partial blood pressure is provided by adjusting acid-alkaline equilibrium. In the body, it is in the associated state in the form of carbon dioxide sodium salts in plasma and blood erythmocytes. When inhalation of large concentrations of carbon dioxide are disturbed by redox processes. The more carbon dioxide in the inhaled air, the less it can be allocated the body. The accumulation of carbon dioxide in the blood and tissues leads to the development of tissue anoxia. With an increase in the content of carbon dioxide in the inhaled air to 3-4%, symptoms of intoxication are noted, at 8% there are severe poisoning and death occurs. The content of carbon dioxide is judged by air purity in residential and public buildings. A significant accumulation of this compound in the air of closed rooms indicates the sanitary disintegration of the premises (the crowding of people, bad ventilation). Carbon dioxide PDC in the air of therapeutic institutions is 0.07%, in the air of residential and public buildings - 0.1%. The latter is adopted as the calculated in determining the effectiveness of ventilation of residential and public buildings.

Nitrogen. Along with oxygen and carbon dioxide, the composition of atmospheric air includes nitrogen, which in quantitative content is the most essential part of atmospheric air.

Nitrogen belongs to inert gases, it does not support breathing and burning. In the atmosphere of nitrogen, life is impossible. In nature, its cycle occurs. Air nitrogen is absorbed by some types of soil bacteria, as well as blue-green algae. Air nitrogen under the influence of electrical discharges turns into oxides, which, wash out from the atmosphere with precipitates, enrich the soil with nitrogen and nitric acids. Under the influence of soil salt bacteria nitrogenous acid They are converted into salts of nitric acid, which, in turn, are absorbed by plants and serve to synthesize protein. It was established that 95% of atmospheric air is assimilated by alive organisms and only 5% is associated as a result of physical processes in nature. Consequently, the bulk of the associated nitrogen has a biogenic origin. Along with the absorption of nitrogen, it is released into the atmosphere. Free nitrogen is formed during the burning of wood, coal, oil, a small amount of free nitrogen is released during the decomposition of organic compounds with denotrophizers. Thus, in nature there is a continuous cycle of nitrogen, as a result of which the atmosphere nitrogen turns into organic compounds. In decomposition of these compounds, nitrogen is restored and enters the atmosphere, and then biological objects are again associated.

Nitrogen is an oxygen diluent, due to this vital function, since pure oxygen respiration leads to irreversible changes in the body. When studying the action on the body of various nitrogen concentrations, it is noted that its increased content in the inhaled air contributes to the onset of hypoxia and asphyxia due to a decrease in the partial pressure of oxygen. With an increase in nitrogen content, death occurs to 93%. The most pronounced adverse properties of nitrogen exhibits in conditions of increased pressure, which is associated with its narcotic action. Also known is the role of nitrogen in the origin of the caisson disease.

Inert gases. Inert gases include argon, neon, helium, krypton, xenon, etc. in chemical terms these gases are inert, in liquids of the body dissolve depending on the partial pressure. The absolute number of these gases in the blood and tissues of the body is negligible. Among the inert gases, Radon, Aktinon and Toron are a special place - the spree products of natural radioactive elements of radium, thorium, actinium.

In chemical terms, these gases are inert, as it has already been noticed above, and their dangerous impact on the body is associated with their radioactivity. IN natural conditions They determine the natural radioactivity of the atmosphere.

Air temperature

The atmospheric air heats up mostly from ground surface Due to the heat obtained by her from the Sun. About 47% solar energyreaching the Earth is absorbed by the earth and turns into heat. Approximately 34% of solar energy reflected back to space From the upper surface of the clouds and the earth's surface, and only the fifth part (19%) of solar energy directly heats the atmosphere. In this connection, the maximum air temperature occurs between 13 and 14 hours, when the ground surface is heated to the greatest extent. Heated surface layers of air climb up, gradually cooling. Therefore, with an increase in height above sea level, the air temperature drops on average 0.6 ° C for every 100 meters of lifting.

The heating of the atmosphere occurs unevenly and depends, above all, from geographic latitude: the greater the distance from the equator to the pole, the greater the angle of inclination of the sun's rays to the plane of the earth's surface, the smaller the amount of energy enters the unit area and heats it less.

The difference in air temperature depending on the latitude of the terrain can be very significant and amount to more than 100 ° C. So, the highest air temperatures (up to + 60 ° C) are registered in Equatorial Africa, minimal (up to -90 ° C) - in Antarctica.

Daily air temperature fluctuations are also very significant in a number of equatorial countries, constantly decreasing towards the poles.

The daily and annual fluctuations in the air temperature affects a number of natural factors: the intensity of solar radiation, nature and terrain, height above sea level, the proximity of the seas, the nature of the seaside flows, vegetation cover, etc.

The effect of unfavorable air temperature on the body is most pronounced in the conditions of stay or work of people outdoors, as well as in some industrial premises, where very high or very low air temperatures are possible. This refers to agricultural workers, builders, oil workers, fishermen, etc., as well as working in hot shops, in ultra-deep mines (1-2 km), specialists serving refrigeration units, etc.

In residential and public premises there are opportunities to ensure the most favorable air temperature (due to heating, ventilation of the premises, the use of air conditioners, etc.).

Atmosphere pressure

On a surface globe Atmospheric pressure fluctuations are related to weather conditions And during the day, as a rule, they do not exceed 4-5 mm Hg.

However, there are special living conditions and human labor activities, in which significant deviations from normal atmospheric pressure are observed, capable of providing a pathological effect.

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 a clinical death will come.

While we breathe, we live. Neither on one planet in solar system There is no close connection between chemistry and biology. Our world is unique.

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

From this article you will learn all the secrets of the Earth's air shell. What happens to the world without one component? What harm can cause? How will a little atmosphere impact on life?

What is air

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

In Alchemy, the air symbol is a triangle, separated by a horizontal line.

In the modern world, it would fit such a definition - the gas mixture surrounding the planet, which protects against the penetration of the radiation of the Sun and the larger doses of ultraviolet.

For a multimillion period of development of the planet transformed gas substances and created a unique protective shield, to see which is almost impossible. The mass fraction of them is incommensurably small for space.

Nothing more affects the world formation. If we remember that part of the air masses is oxygen, what happens on earth without it? Buildings and structures collapse.

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

The sea and oceans, evaporating in the form of hydrogen, will disappear. And when the planet becomes similar to the Moon, the radiation fire, burning 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 the air

Almost the whole earthly atmosphere consists of only five gases: nitrogen, oxygen, water vapor, argon and carbon dioxide.

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

Percent air composition

Ideally assembled air to the jar consists on:

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

Smaller components it is:

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

The composition of inhaled and exhaled air

Breathing prevails over other human needs. From the school course, everyone knows that man inhales oxygen, and carbon dioxide exhales. Although other substances are present in the air in the air in except for pure O 2.

Inhale - exhale. A similar cycle is repeated about 22,000 times a day in the process of which oxygen is consumed, which supports the viability of the human body. The problem is that the tender pulmonary fabric is attacked by air pollution, cleaning solutions, fibers, vapors and dust.

In the first half of the article it was said about the reduction of oxygen, but what will be with increasing. Two main gas concentration would lead to a reduction in fuel consumed in cars.

Inhaling more oxygen, a person would have become much psychologically positive. However, some insect favorable climate would increase in size. There are a number of theories predicting it. It seems that no one would like to meet with a spider size with a dog, and about the growth of large representatives you can only fantasize.

Inhaling less heavy metals, humanity could defeat a number of complex diseases, but such a project will require a lot of strength. There is a whole program aimed at creating a practical paradise on Earth: in every home, in a room, a city or country. Her goal is to make the atmosphere cleaner, save people from dangerous work in mines and metallurgy. The place where jobs would take the masters of their business.

It is important that inhaling a clean, not the touched industry air can be, but for this you need a political, and better world will. In the meantime, people are engaged in search of money and cheap (dirty) technologies, it remains to inhale only the urban could. As long as this will last unknown.

Visually assess the atmospheric air of the capital of our Motherland, which inhales not one dozen people will allow the map.

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, which are dangerous to health of living organisms: people, animals or plants.

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

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

All of the above erupts in the air various types of hazardous substances and toxins, exceeding the norms in tens, and sometimes hundreds of times. In combination with natural sources - Volcanoes, geysers and other - a deadly cocktail of poisonous air masses is created, which is familiar to "able".

Evidence of the guilt of each person is obvious. Our personal choice and industry can have a detrimental effect on such necessary gas. Behind the age of the technological, Nature managed to suffer, and therefore, the ignition is inevitable.

Increasing emissions, humanity is approaching the abyss, the return of which is not and can not be. It is not too late, it should be fixed at least something. It has been proven that alternative industrial technologies can help clean air in Moscow, St. Petersburg, Tokyo, Berlin and any other major city.

Here are some ways to solve:

1. Replace gasoline with electricity in cars, and the sky above the city will be a little more beautiful.
2. Remove coal stations from cities, let them go to the country's history, start using the energy of the sun, water, wind. Then, after the rain, the soot will not fly from the tube of the next plant, and there will be only the smell of "freshness".
3. Put the tree in the park. If this will do thousands, then the hospitals will stop visiting asthmatics and depressive people in search of a unique recipe from the mouth of the psychologist.

Let's notify immediately, nitrogen in the air occupies most, however, the chemical composition of the remaining share is very interesting and diverse. If short, the list of basic elements is as follows.

However, we will give a small explanation on the functions of these chemical elements.

1. Nitrogen

The nitrogen content in the air is 78% by volume and 75% by weight, that is, this element dominates the atmosphere, has the title of one of the most common on Earth, and, in addition, it also contains outside the human habitat - in uranium, neptune and in interstellar spaces. So, how much nitrogen in the air, we have already figured out, the question of its function remains. Nitrogen is necessary for the existence of living beings, it is part of:

• proteins;
• amino acids;
• nucleic acids;
• chlorophyll;
• hemoglobin, etc.

On average, about 2% of the living cells make up the nitrogen atoms, which explains why so much nitrogen in the air in the percentage of volume and mass.
Nitrogen is also one of the inert gases produced from atmospheric air. Ammonia is synthesized from it, used for cooling and for other purposes.

2. Oxygen

The oxygen content in the air is one of the most popular questions. Keeping intrigue, distracted by one funny fact: Oxygen was discovered twice - in 1771 and 1774, however, due to the difference in opening publications, the honors of the discovery of the element got the English chemist Joseph attracted, which actually allocated oxygen by the second. So, the proportion of oxygen in the air fluctuates about 21% by volume and 23% by weight. Together with nitrogen, these two gas form 99% of the entire terrestrial air. However, the percentage of oxygen in the air is less than nitrogen, and while we do not have problems with breathing. The fact is that the amount of oxygen in the air is optimally calculated precisely for normal respiration, in its pure form this gas acts on the body like poison, leads to difficulties in the work of the nervous system, respiratory failures and blood circulation. At the same time, the lack of oxygen also negatively affects health, causing oxygen fasting and all associated unpleasant symptoms. Therefore, how much oxygen in the air is contained, so much and need for a healthy full breathing.

3. Argon

Argon in the air takes the third place, it does not smell, colors and taste. The significant biological role of this gas has not been identified, but it has a narcotic effect and is even considered doping. Argon extracted from the atmosphere is used in industry, medicine, to create an artificial atmosphere, chemical synthesis, fire extinguishing, creating lasers, etc.

4. Carbon dioxide

Carbon dioxide is the atmosphere of Venus and Mars, its percentage in the earthly air is much lower. At the same time, a huge amount of carbon dioxide is contained in the ocean, it is regularly supplied by all breathable organisms, is ejected by industry. In person's life, carbon dioxide is used in fire extinguishing, food industry as gas and as a food additive E290 - a preservative and a baking powder. In the solid form of carbon dioxide - one of the most famous refrigerants "dry ice".

5. Neon

The very mysterious light of disco lanterns, bright signs and modern headlights use the fifth prevalence of the chemical element, which also inhales a person - neon. Like many inert gases, neon has a narcotic effect on a person under a certain pressure, but it is precisely this gas that is used in the preparation of divers and other people working at increased pressure. Also neon-helium mixtures are used in medicine during respiratory disorders, neon itself is used for cooling, in the production of signal lights and those most neon lamps. However, contrary to the stereotype, neon light is not blue, but red. All other colors give lamps with other gases.

6. Methane

Methane and air are very ancient history: In the primary atmosphere, even before the appearance of a person, methane was in much more. Now this gas extracted and used as fuel and raw materials in production is not so widespread in the atmosphere, but still stands out from the ground. Modern research Set the role of methane in the breathing and vital activity of the human body, but there are no authoritative data on this account.

7. Helium

Looking at how much helium in the air, any will understand that this gas does not apply to the number of primary importance. Indeed, it is difficult to determine the biological significance of this gas. Apart from a funny distortion of voices when inhaling helium from the ball 🙂 However, helium is widely used in industry: in metallurgy, food industry, for filling the aeronautic ships and meteorological probes, in lasers, nuclear reactors etc.

8. Kripton

We are not talking about the homeland of Superman 🙂 Krypton - an inert gas, which is three times heavier than air, chemically inert, is extracted from air, used in incandescent lamps, lasers and is still actively studied. From the interesting properties of Crypton, it is worth noting that at a pressure of 3.5 atmosphere, it has a narcotic effect on a person, and at 6 atmospheres it acquires a sharp smell.

9. Hydrogen

Hydrogen in the air takes 0.00005% by volume and 0.00008% by weight, but it is it that is the most common element in the universe. It is quite possible to write a separate article about its history, production and application, so you can now restrict ourselves to a small list of industries: chemical, fuel, food industry, aviation, meteorology, electric power industry.

10. Xenon

The latter in the composition of the air was originally considered only impurity to Crypton. Its name is translated as "someone else's", and the percentage of content and on Earth, and beyond its limits, which led him high cost. Now without xenon, it is not possible: the production of powerful and impulse light sources, diagnosis and anesthesia in medicine, engines spacecraft, rocket fuel. In addition, when inhalation, xenon significantly reduces the voice (reverse effect of helium), and more recently, inhalation of this gas is attached to the doping list.

The gas composition of atmospheric air is one of the most important indicators of the state of the natural environment. The main gas content near the surface of the Earth in percent is:

· Nitrogen - 78.09%,

· Oxygen - 20.95%,

· Water vapor - 1.6%,

· Argon - 0.93%,

· Carbon dioxide - 0.04% (data is given in terms of normal conditions Tº \u003d 25 ºC, p \u003d 760 mm Hg).

Nitrogen - Gas, which is the main component of the air. In conventional atmospheric pressure and low nitrogen temperatures inert. The dissociation of nitrogen molecules and their disintegration on atomic nitrogen occurs at the heights of more than 200 km.

Oxygen - It is produced by plants in the process of photosynthesis (approximately 100 billion tons annually). During the chemical evolution, one of the earliest major changes was the transition from the rehabilitation atmosphere to the oxidative, in which biological systems began to develop, characterizing today's life on Earth. 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 will stop - breathing, burning, rotting.

Carbon dioxide (carbon dioxide) enters the air as a result of fuel combustion processes, respiration, rotting and decomposition of organic substances. The essential accumulation of carbon dioxide in the atmosphere does not occur, as it is absorbed by plants in the process of photosynthesis.

In addition, in the air always contains: neon, helium, methane, crypton, nitrogen oxides, xenon, hydrogen. But these components are contained in quantities that do not exceed the thousands of percent. This composition of atmospheric air can be considered inherent in modern absolutely clean air. However, so it never happens.

Many impurities falling into atmospheric air from various natural and artificial sources in different parts Earth with time-changing intensity make up its non-permanent impurities that can be called conditionally pollution .

Among the natural pollution factors allocate :

but) extraterrestrial air pollution with cosmic dust and cosmic radiation;

b) Earthly pollution of the atmosphere when eruption of volcanoes, weathered mountain breeds, dusty Buryakh, forest fires arising from lightning strikes, removal of marine salts.

Conditionally divide the natural contamination of the atmosphere on continental and sea, as well as inorganic and organic.

One of the most constant impurities present in the atmospheric air is suspended particles. They can be both mineral and organic, a significant part of which are pollen and spores of plants, spores of mushrooms, microorganisms. Often, dust is formed by the smallest particles of the soil and, in addition to mineral, contains some organic substances.

With the smoke of forest fires in the air, particles of soot fall, that is, carbon, and the products of incomplete combustion of wood, that is, various organic substancesAmong which there are many phenolic compounds with mutagenic and carcinogenic properties.

Volcanic dust and ash contain a certain amount of soluble potassium salts, calcium, magnesium and other substances important for mineral nutrition of plants. Oxides of sulfur, nitrogen, carbon, as well as chlorine, fall into the atmosphere with volcanic gases. Carbon dioxide enters the atmospheric carbon stock, nitrogen and sulfur oxides are quickly washed with rains and fall on the soil in the form of weak solutions of acids.

The atmospheric air is in constant interaction and metabolism with a stone shell of the Earth - a lithosphere and aqueous shell - hydrosphere. The role of the atmosphere in the cycle of substances causing life on our planet is very high. Whole through the atmosphere passes the cycle of water. The volcanic ashes carrying by the wind enriches the soil by elements of plants mineral nutrition. The carbon dioxide discharged by volcanoes, falling into the atmosphere, is included in the carbon cycle and is absorbed by plants.

Natural sources of atmospheric impurities have always existed. The removal paths for different impurities can be different: dust loss, leaning with precipitations, absorbing by plants or water surface and others. Exists natural equilibrium Between the admission of impurities into the atmosphere and its self-cleaning, with the result that for any substance part of the impurities, you can specify the natural limits of its content in the air, which is called background.