What gas is contained in the air? What gases does air consist of? II. Learning new material

06.03.2020

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The composition of air includes many elements that largely determine life activity. human body, making it better or worse. Carbon monoxide produced by car engines and tobacco smoking negatively affects human health. Increased amounts of this gas in the air can cause nausea, headache, drowsiness. The composition of the air also includes an element visible to us - dust, which is particles of mineral and organic origin. The most important component of air is oxygen. A sufficient amount of it ensures normal breathing and the functioning of the lungs and circulatory system. Most of the air contains nitrogen. This gas serves as a diluent for other gases. As a result of respiration, carbon dioxide, which is part of the air along with industrial emissions. It is used for artificial respiration, and, in addition, the level of carbon dioxide indicates the level of air pollution. In addition to the listed gases, the atmosphere also includes sulfur dioxide and carbon monoxide (formed when incomplete combustion organic matter). The listed gases form the basis of the air mixture, but their percentage may change, for example, in cities with a high carbon dioxide content. On average, the ratio of atmospheric gases is as follows: 78% nitrogen, 21% oxygen, about 0.035% carbon dioxide, about 1% ozone, inert gases. Finally, in addition to gases, air always contains a small amount of water vapor.

Impurities

Many mechanical impurities enter the air as a result of the combustion of organic and inorganic substances, industrial waste in the form of smoke, soot, soot, small soil particles. If sandy soil predominates in a certain area, the dust content of the soil increases significantly. Asphalt roads, on the contrary, reduce dust levels, but the construction process itself leads to significant air pollution with soot.

The air envelope can also contain various microorganisms, including microbes, bacteria, fungi, viruses, and yeast cells. This is why it is possible to contract a cold in a poorly ventilated area with large cluster people where the concentration of microorganisms significantly exceeds the norm. In such conditions, not only a person who sneezes, but also a person simply speaking, sprays tiny droplets that spread with the air over a distance of up to 10 meters.

main gas in air

Alternative descriptions

Gas that makes metal brittle

A gas that makes up 78% air

Main "air filler"

The main component of the air you breathe, which is pure form you can't breathe

Air Component

Fertilizer in the air

Chemical element - the basis of a number of fertilizers

Chemical element, one of the main nutrients plants

Chemical element, component air

Nitrogenium

Liquid refrigerant

Chemical element, gas

Magic sword of Paracelsus

In Latin, this gas is called “nitrogenium”, that is, “giving birth to saltpeter”

The name of this gas comes from the Latin word for lifeless.

This gas, a component of air, was practically absent from the Earth's primary atmosphere 4.5 billion years ago.

A gas whose liquid is used to cool ultra-precision instruments

What gas is in liquid state stored in a Dewar flask?

The gas that froze Terminator II

Gas cooler

What gas extinguishes fire?

Most abundant element in the atmosphere

Base of all nitrates

Chemical element, N

Freezing Gas

Three quarters air

Contains ammonia

Gas from air

Gas number 7

Element from saltpeter

The most popular gas

Element from nitrates

Liquid gas from a vessel

No. 1 gas in the atmosphere

Fertilizer in the air

78% air

Gas for cryostat

Almost 80% air

Meaning for humans

The air environment is not only a source of oxygen. It allows a person to see, perceive spatial signals, and use the senses. Hearing, vision, smell - they all depend on the condition air environment.

Second important point- defence from solar radiation. The atmosphere envelops the planet with a shell that blocks part of the spectrum sun rays. As a result, about 30% of solar radiation reaches the earth.

The air environment is a shell in which precipitation forms and evaporation rises. It is she who is responsible for half of the moisture exchange cycle. Precipitation formed in the atmosphere affects the functioning of the World Ocean, contributes to the accumulation of moisture on continents, and determines the destruction of open rocks. She takes part in climate formation. Circulation of air masses is the most important factor in the formation of specific climatic zones and natural areas. Winds arising above the Earth determine temperature, humidity, precipitation levels, pressure, and weather stability in the region.

Currently extracted from thin air chemical substances: oxygen, helium, argon, nitrogen. The technology is still at the testing stage, but in the future this can be considered a promising direction for the chemical industry.

The above are obvious things. But the air environment is also important for industry and economic activity person:

It is the most important chemical agent for combustion and oxidation reactions.
Transfers heat.

Thus, atmospheric air is a unique air environment that allows living things to exist and humans to develop industry. There is a close interaction between the human body and the air environment. If you violate it, serious consequences will not keep you waiting.

Air pollution is a serious environmental problem this century. Toxic chemical compounds, organic substances, pathogenic microorganisms - any large emissions into the atmosphere change its composition. She is like any other part geographic envelope The earth is capable of self-purification and self-regulation. The question is when the self-purification resources will be completely depleted.

Gas composition

What gases make up the atmosphere? The chemical composition of atmospheric air is relatively constant, this the most important indicator, which reflects the state of the environment.

The composition of atmospheric air includes the following gases:

Nitrogen – 78%.
21% oxygen.
Water vapor is about 1.5%, the figure strongly depends on the climate zone and air temperature.
Just under 1% argon.
0.04% carbon dioxide
Ozone.

As well as other gases that are an integral and permanent component of atmospheric air. The gas composition of atmospheric air is maintained due to natural cycle substances. Oxygen, which is produced by plants, is extremely important for human life. Thus, scientists were able to calculate that the loss of just 3% of oxygen can lead to a complete stop of all biological processes on Earth. Ozone is required to dilute oxygen and is also concentrated in upper layers the stratosphere, creating the ozone layer that protects the Earth from solar radiation.

Atmospheric air also contains carbon dioxide (carbon dioxide), which is formed in different ways - during the decomposition of organic substances, if fuel is heated or burned, during the respiration of animals and plants. It is mainly absorbed by plants - therefore maintaining sufficient vegetation cover is extremely important for stable operation atmosphere.

Composition consistency

The air environment is capable of self-regulation, that is, maintaining a constant composition. If its chemical composition changed, only bacteria would remain on Earth. But, fortunately for humans, it is able to eliminate local pollution.

Self-regulation occurs due to:

Precipitation, which falls as rainwater, introduces pollutants into the soil.
Chemical reactions that occur directly in the air with the participation of oxygen and ozone. These reactions are oxidative in nature.
Plants that saturate the air with oxygen and absorb carbon dioxide.

However, no amount of self-regulation can eliminate the harm that industry causes. Therefore, sanitary protection of atmospheric air has recently become especially important.

Hygienic characteristics of air

Pollution is the process of introducing impurities into the atmospheric air that should not normally exist. Pollution can be natural or artificial. Impurities that come from natural sources, are neutralized in the planetary cycle of matter. With artificial pollution the situation is more complicated.

Natural pollution includes:

Cosmic dust.
Impurities formed during volcanic eruptions, weathering, and fires.

Artificial pollution is anthropogenic in nature. There are global and local pollution. Global is all emissions that can affect the composition or structure of the atmosphere. Local is a change in indicators in a specific area or in a room used for living, work or public events.

Ambient air hygiene is an important section of hygiene that deals with the assessment and control of indoor air parameters. This section appeared in connection with the need for sanitary protection. The hygienic importance of atmospheric air is difficult to overestimate - along with breathing, all the impurities and particles contained in the air enter the human body.

Hygienic assessment includes the following indicators:

Physical properties of atmospheric air. This includes temperature (the most common violation of SanPin in workplaces is that the air heats up too much), pressure, wind speed (at open areas), radioactivity, humidity and other indicators.
Presence of impurities and deviation from standard chemical composition. Atmospheric air is characterized by its suitability for breathing.
The presence of solid impurities - dust, other microparticles.
The presence of bacterial contamination – pathogenic and conditionally pathogenic microorganisms.

To compile a hygienic characteristic, the readings obtained on four points are compared with established standards.

Environmental protection

Recently, the state of atmospheric air has been causing concern among environmentalists. As industry develops, environmental risks also grow. Factories and industrial zones not only destroy the ozone layer, heating the atmosphere and saturating it with carbon impurities, but also reduce the hygienic quality of air. Therefore, in developed countries it is customary to carry out complex events on air protection.

Main directions of protection:

Legislative regulation.
Development of recommendations for the location of industrial zones, taking into account climatic and geographical factors.
Carrying out measures to reduce emissions.
Sanitary and hygienic control at enterprises.
Regular monitoring of composition.

Protection measures also include planting green spaces, creating artificial reservoirs, creation of barrier zones between industrial and residential areas. Recommendations for carrying out protective measures have been developed by organizations such as WHO and UNESCO. State and regional recommendations are developed on the basis of international ones.

Currently, the problem of air hygiene is receiving more and more attention. Unfortunately, on this moment The measures taken are not enough to completely minimize anthropogenic harm. But we can hope that in the future, along with the development of more environmentally friendly production, it will be possible to reduce the load on the atmosphere.

The purpose of the lesson: develop knowledge about the composition and properties of air.

Lesson objectives:

Reveal the characteristics of the gases that make up the atmosphere and their significance in nature and in human life.
Reveal environmental problems that affect changes in the composition and properties of air.
Contribute to the formation of students complete picture world thanks to the use interdisciplinary connections biology, chemistry, ecology.
Develop the ability to search, find and present information using ICT.
Develop the ability to perform simple experiments.
Develop the ability to work in groups.
Promote the formation of an active life position students in nature conservation.

Equipment:

natural history textbook for grade 5 (authors: Pakulova V.M., Ivanova N.V.);
schemes “Nitrogen cycle”, “Oxygen producers and consumers”;
test tubes with lime water, glass tubes, rubber bulb;
drawings depicting environmental problems, didactic material.

During the classes

The class is divided into 4 groups in advance.

I. Updating of basic knowledge.

Guys, I would like to start today’s lesson with a riddle:

There is an invisible man
Doesn't ask to come into the house
And before people
He's running, in a hurry. (Students' answers.)

Of course we're talking about about the air.

Answer the questions:

What is the name of air envelope Earth?
Why does atmosphere matter?
In what layer of the atmosphere do all living organisms live? Why?

The topic of our lesson is “Air - mixture various gases. Air protection." (Students write down the topic of the lesson in their notebook.)

II. Learning new material.

1) Air composition.

Air surrounds us everywhere. It is necessary for life for all living organisms.

What gases are included in air? (Students' answers.)

To find out what other gases are in the air, turn to Fig. 38 on p. 67.

What gases are found in the air the most?

What proportion is nitrogen?

What proportion is oxygen?

Based on the above, we conclude: air is a mixture of various gases. (Students' answers.)

And we remember that the substances included in the mixtures retain their properties.

Let's get acquainted with the properties of individual gases.

2) Nitrogen.

(Student's message.)

In the air largest volume occupies nitrogen gas. Translated from Latin, “nitrogen” means “lifeless” because. back in the 18th century, D. Rutherford K. Scheele, and later Lavoisier, discovered a gas in the air that did not support combustion and respiration.

Nitrogen is released into the atmosphere from earth's crust as a product of the vital activity of microorganisms. The composition of rocks contains the chemical element nitrogen 50 times more than in the atmosphere.

Nitrogen, as a chemical element, is very important for living organisms because... it is part of proteins. But most living organisms cannot absorb it from the atmosphere. Only some bacteria are able to consume it from the air. During a thunderstorm, powerful electrical discharges jump through the atmosphere under the influence of which they form complex connections nitrogen. They fall into the soil with precipitation. Plants absorb nitrogen from the soil, and animals absorb nitrogen by eating plants or other animals that eat plants. When living organisms die, their bodies decompose and nitrogen is released back into the soil.

(The diagram “Nitrogen cycle in nature” is demonstrated.)

What name can be given to the process described and shown in this diagram? (Students' answers.)

3) Oxygen.

Oxygen makes up one fifth of air. Its properties differ from nitrogen.

What properties of oxygen do we know? (Supports combustion and respiration.)

What do these two phenomena have in common? (Oxygen is used, oxidation occurs, energy is released.)

With a lack of oxygen, the functioning of all organs in organisms that use it for breathing, and these are the majority, is disrupted.

Let's turn to the history of the discovery of oxygen (working with the textbook p. 67-68).

4) Experimental proof of the presence of oxygen in the air.

How to prove the presence of oxygen in the air? (Light a match, a candle.)

Demonstration of the experiment by the teacher: light a candle and cover with a glass cover.

Why does the candle go out?

What gas is produced during combustion?

Does it support combustion and breathing? (Students' answers.)

5) Experimental proof of the presence of carbon dioxide in atmospheric air.

To prove the presence of carbon dioxide we need lime water. This is a clear solution. When it interacts with carbon dioxide, a white substance is formed, which is why lime water becomes cloudy.

Demonstration of experience by teacher: Using a rubber bulb, blow air through the lime water several times (clouding is observed).

6) Experimental proof of the presence of carbon dioxide in exhaled air.

In front of you are test tubes with lime water. I suggest you take a deep breath and slowly exhale air through the tube into the test tube. In this case, it is necessary to comply with safety regulations - you can't inhale through a straw!

(Conduct the experiment by students in groups.)

What conclusion can be drawn about the carbon dioxide content in inhaled and exhaled air?

Conclusion: There is less carbon dioxide in the inhaled air than in the exhaled air.

Why is it necessary to ventilate the office during breaks?

7) The relative constancy of the oxygen and carbon dioxide content in the atmosphere.

There are a huge number of oxygen consumers on earth.

Why is its content in the atmosphere relatively constant?

Working with the “Oxygen Consumers and Producers” diagram.

Interesting information. Land plants produce 53 billion tons of oxygen annually, and algae produce almost 10 times more.

8) Ecological problems, affecting the composition and properties of air.

Yes, plants maintain the relative constancy of oxygen in the atmosphere, but there are problems that are caused by human activity and affect changes in the composition and properties of the air.

Listening to messages and watching student presentations (from the group) on topics:

Destruction of the ozone layer.
Deforestation. Forest fires.
Global warming.
Air pollution from chemical waste.

9) Impurities in the air.

What impurities are in the air? (Students' answers.)

Water vapor determines air humidity.

Where is the air humidity highest?

Interesting information. There are also unusual impurities in the air. In the summer of 1933, in the Primorsky Territory, sea jellyfish fell from the sky, and in 1974, in the suburbs of Ashgabat, it rained live frogs.

What is the reason for these unusual rains?

III. Consolidation.

Today you have received a lot of information about air. And as Confucius said:

“I hear and I forget.
I see and I remember.
I do and I understand."

Therefore, I suggest that you, working in groups, complete several tasks (tasks are distributed among students in groups).

Task 1. Fill out the table.

Gas name	Coloring	Smell	Does it support combustion?	Does it support breathing?	Contents in the air

Task 2. Analyze the information. Answer the questions.

Air dissolves quite well in water, especially cold water. It contains not 1/5 oxygen, as in the atmosphere, but 1/3. If ice water Place in a warm place; air bubbles will appear on the walls of the vessel.

What do fish breathe?
Is it possible to pour boiled water into an aquarium?

Task 3. Your suggestions for preserving the air composition. Your personal contribution.

Listening to student responses in groups.

IV. Lesson summary.

Assessment of student activities.

Homework: paragraph 16; compile a “Collection of proverbs, sayings, riddles about the air”; compose a poem or fairy tale about the air (optional).

Well done! Thank you for the fruitful collaboration.

We all know very well that without air, not a single living creature can live on earth. Air is vital for all of us. Everyone, from children to adults, knows that it is impossible to survive without air, but not everyone knows what air is and what it consists of. So, air is a mixture of gases that cannot be seen or touched, but we all know very well that it is around us, although we practically do not notice it. To conduct research of various types, including, you can in our laboratory.

We can only feel air when we feel it strong wind or we are near a fan. What does air consist of? It consists of nitrogen and oxygen, and only a small part of argon, water, hydrogen and carbon dioxide. If we consider the composition of air in percentage, then nitrogen is 78.08 percent, oxygen 20.94%, argon 0.93 percent, carbon dioxide 0.04 percent, neon 1.82 * 10-3 percent, helium 4.6 * 10-4 percent, methane 1.7 * 10-4 percent, krypton 1.14*10-4 percent, hydrogen 5*10-5 percent, xenon 8.7*10-6 percent, nitrous oxide 5*10-5 percent.

The oxygen content in the air is very high, because it is oxygen that is necessary for the functioning of the human body. Oxygen, which is observed in the air during breathing, enters the cells of the human body and participates in the oxidation process, as a result of which the energy needed for life is released. Also, oxygen, which is present in the air, is required for the combustion of fuel, which produces heat, as well as when receiving mechanical energy in internal combustion engines.

Also extracted from air when liquefied inert gases. How much oxygen is in the air, if you look at it as a percentage, then oxygen and nitrogen in the air are 98 percent. Knowing the answer to this question, another question arises, what gaseous substances are included in the air.

So, in 1754, a scientist named Joseph Black confirmed that air consists of a mixture of gases, and not a homogeneous substance as previously thought. The composition of the air on earth includes methane, argon, carbon dioxide, helium, krypton, hydrogen, neon, and xenon. It is worth noting that the percentage of air may vary slightly depending on where people live.

Unfortunately, in major cities the proportion of carbon dioxide as a percentage will be higher than, for example, in villages or forests. The question arises what percentage of oxygen is in the air in the mountains. The answer is simple, oxygen is much heavier than nitrogen, so there will be much less of it in the air in the mountains, this is because the density of oxygen decreases with altitude.

Level of oxygen in the air

So, regarding the ratio of oxygen in the air, there are certain standards, for example, for working area. In order for a person to be able to fully work, the oxygen level in the air is from 19 to 23 percent. When operating equipment in enterprises, it is necessary to ensure the tightness of the devices, as well as various machines. If, when testing the air in the room where people work, the oxygen level is below 19 percent, then it is imperative to leave the room and turn on emergency ventilation. You can control the level of oxygen in the air at the workplace by inviting the EcoTestExpress laboratory and research.

Let's now define what oxygen is

There is oxygen chemical element periodic table Mendeleev's elements, oxygen has no smell, no taste, no color. Oxygen in the air is extremely necessary for human breathing, as well as for combustion, because it’s no secret that if there is no air, then no materials will burn. Oxygen contains a mixture of three stable nuclides, mass numbers of which there are 16, 17 and 18.

So, oxygen is the most abundant element on earth, as far as percentage then the largest percentage of oxygen is found in silicates, which is about 47.4 percent of the mass of the solid earth’s crust. Also in maritime and fresh waters The entire earth contains a huge amount of oxygen, namely 88.8 percent; as for the amount of oxygen in the air, it is only 20.95 percent. It should also be noted that oxygen is part of more than 1,500 compounds in the earth’s crust.

As for the production of oxygen, it is obtained by separating air at low temperatures. This process happens like this: first, air is compressed using a compressor; when compressed, the air begins to heat up. Compressed air let cool until room temperature, and after cooling they ensure its free expansion.

When expansion occurs, the temperature of the gas begins to drop sharply; after the air has cooled, its temperature can be several tens of degrees below room temperature, such air is again subjected to compression and the released heat is removed. After several stages of compressing and cooling the air, a number of other procedures are performed, as a result of which pure oxygen is separated without any impurities.

And here another question arises: what is heavier: oxygen or carbon dioxide. The answer is simply of course carbon dioxide will be heavier than oxygen. The density of carbon dioxide is 1.97 kg/m3, but the density of oxygen, in turn, is 1.43 kg/m3. As for carbon dioxide, it turns out that it plays one of the main roles in the life of all life on earth, and also has an impact on the carbon cycle in nature. It has been proven that carbon dioxide is involved in the regulation of respiration, as well as blood circulation.

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What is carbon dioxide?

Now let’s define in more detail what carbon dioxide is, and also designate the composition of carbon dioxide. So, carbon dioxide in other words is carbon dioxide, it is a colorless gas with a slightly sour odor and taste. As for air, the concentration of carbon dioxide in it is 0.038 percent. The physical properties of carbon dioxide are that it does not exist in a liquid state under normal conditions. atmospheric pressure, but goes straight from solid state into gaseous

Carbon dioxide in solid form is also called dry ice. Today, carbon dioxide is a participant in global warming. Producing carbon dioxide through combustion various substances. It is worth noting that when industrial production carbon dioxide is pumped into cylinders. Carbon dioxide pumped into cylinders is used as fire extinguishers, as well as in the production of carbonated water, and is also used in air guns. And also in the food industry as a preservative.

Composition of inhaled and exhaled air

Now let's look at the composition of inhaled and exhaled air. First, let's define what breathing is. Breathing is a complex, continuous process by which the gas composition blood. The composition of inhaled air is 20.94 percent oxygen, 0.03 percent carbon dioxide and 79.03 percent nitrogen. But the composition of exhaled air is only 16.3 percent oxygen, as much as 4 percent carbon dioxide and 79.7 percent nitrogen.

You can notice that the inhaled air differs from the exhaled air in the oxygen content, as well as in the amount of carbon dioxide. These are the substances that make up the air we breathe and exhale. Thus, our body is saturated with oxygen and releases all unnecessary carbon dioxide outside.

Dry oxygen improves electrical as well as protective properties films due to the absence of water, as well as their compaction and reduction of volumetric charge. Also, dry oxygen under normal conditions cannot react with gold, copper or silver. To spend chemical analysis air or other laboratory test, including, can be done in our EcoTestExpress laboratory.

Air is the atmosphere of the planet on which we live. And we always have the question of what is included in the air, the answer is simply a set of gases, as it was already described above which gases are in the air and in what proportion. As for the content of gases in the air, everything is easy and simple; the percentage ratio for almost all areas of our planet is the same.

Composition and properties of air

Air consists not only of a mixture of gases, but also of various aerosols and vapors. The percentage composition of air is the ratio of nitrogen, oxygen and other gases in the air. So, how much oxygen is in the air, the simple answer is just 20 percent. Component composition gas, as for nitrogen, it contains the lion's share of all air, and it is worth noting that when high blood pressure nitrogen begins to have narcotic properties.

This is of no small importance, because when divers work, they often have to work at depths under enormous pressure. Much has been said about oxygen because it is of great importance for human life on our planet. It is worth noting that a person’s inhalation of air with increased oxygen is not a long period does not have a detrimental effect on the person himself.

But if a person inhales air from increased level oxygen for a long time, this will lead to pathological changes in the body. Another main component of air, about which much has already been said, is carbon dioxide, as it turns out that a person cannot live without it as well as without oxygen.

If there was no air on earth, then not a single living organism would be able to live on our planet, much less function somehow. Unfortunately, in modern world a huge number of industrial facilities that pollute our air have recently increasingly called for what needs to be protected environment and also monitor the cleanliness of the air. Therefore, you should take frequent measurements of the air to determine how clean it is. If it seems to you that the air in your room is not clean enough and this is to blame external factors you can always contact the EcoTestExpress laboratory, which will carry out everything necessary tests(, research) and will give a conclusion about the purity of the air you inhale.