Unlike the hot and cold planets of our solar system, on the planet Earth there are conditions that allow life in a certain form. One of the main conditions is the composition of the atmosphere, which gives all living things the opportunity to breathe freely and protects from the deadly radiation that reigns in space.
What is the atmosphere made of?
The Earth's atmosphere is made up of many gases. Basically which occupies 77%. Gas, without which life on Earth is unthinkable, occupies a much smaller volume, the oxygen content in the air is 21% of the total volume of the atmosphere. The last 2% is a mixture of various gases, including argon, helium, neon, krypton and others.
The Earth's atmosphere rises to a height of 8,000 km. Breathable air exists only in the lower layer of the atmosphere, in the troposphere, which reaches 8 km at the poles, upwards, and 16 km above the equator. As altitude increases, the air becomes thinner and the more oxygen is depleted. To consider what oxygen content in the air is on different height, let's take an example. At the peak of Everest (altitude 8848 m), the air holds this gas 3 times less than above sea level. Therefore, the conquerors of high mountain peaks - climbers - can climb to its top only in oxygen masks.
Oxygen is the main condition for survival on the planet
At the beginning of the existence of the Earth, the air that surrounded it did not have this gas in its composition. This was quite suitable for the life of the simplest - single-celled molecules that floated in the ocean. They didn't need oxygen. The process began about 2 million years ago, when the first living organisms, as a result of the photosynthesis reaction, began to emit small doses of this gas obtained as a result of chemical reactions, first into the ocean, then into the atmosphere. Life evolved on the planet and took on a variety of forms, most of which have not survived to our times. Some organisms eventually adapted to life with the new gas.
They learned to use its power safely inside the cell, where it acted as a power plant, in order to extract energy from food. This way of using oxygen is called breathing, and we do it every second. It was breathing that made it possible for the emergence of more complex organisms and people. Over millions of years, the oxygen content in the air has skyrocketed to modern level- about 21%. The accumulation of this gas in the atmosphere contributed to the creation of the ozone layer at a height of 8-30 km from the earth's surface. At the same time, the planet received protection from the harmful effects of ultraviolet rays. The further evolution of life forms on water and on land increased rapidly as a result of increased photosynthesis.
anaerobic life
Although some organisms have adapted to the rising levels of the gas being released, many of the simplest life forms that existed on Earth have disappeared. Other organisms survived by hiding from oxygen. Some of them today live in the roots of legumes, using nitrogen from the air to build amino acids for plants. The deadly organism botulism is another "refugee" from oxygen. He quietly survives in vacuum packaging with canned foods.
What oxygen level is optimal for life
Prematurely born babies, whose lungs are not yet fully opened for breathing, fall into special incubators. In them, the oxygen content in the air is higher by volume, and instead of the usual 21%, its level of 30-40% is set here. Toddlers with severe breathing problems are surrounded by air with 100% oxygen levels to prevent damage to the child's brain. Being in such circumstances improves the oxygen regime of tissues that are in a state of hypoxia, and normalizes their vital functions. But its excessive amount in the air is just as dangerous as the lack of it. Too much oxygen in a child's blood can damage the blood vessels in the eyes and cause vision loss. This shows the duality of the properties of the gas. We must breathe it in order to live, but its excess can sometimes become a poison for the body.
Oxidation process
When oxygen combines with hydrogen or carbon, a reaction called oxidation takes place. This process causes the organic molecules that are the basis of life to decay. In the human body, oxidation proceeds as follows. Red blood cells collect oxygen from the lungs and carry it throughout the body. There is a process of destruction of the molecules of the food that we eat. This process releases energy, water and carbon dioxide. The latter is excreted by the blood cells back into the lungs, and we exhale it into the air. A person can suffocate if they are prevented from breathing for more than 5 minutes.
Breath
Consider the oxygen content in the air we breathe. Atmospheric air that enters the lungs from the outside when inhaled is called inhaled, and the air that comes out through respiratory system when exhaling, - exhaled.
It is a mixture of air that filled the alveoli with that which is in the respiratory tract. Chemical composition air that a healthy person inhales and exhales vivo, practically does not change and is expressed by such numbers.
Oxygen is the main constituent of air for life. Changes in the amount of this gas in the atmosphere are small. If by the sea the oxygen content in the air contains up to 20.99%, then even in the very polluted air of industrial cities, its level does not fall below 20.5%. Such changes do not reveal effects on the human body. Physiological disorders appear when the percentage of oxygen in the air drops to 16-17%. At the same time, there is a clear one that leads to a sharp drop in vital activity, and with an oxygen content in the air of 7-8%, a lethal outcome is possible.
Atmosphere in different eras
The composition of the atmosphere has always influenced evolution. At different geological times, due to natural disasters, rises or falls in the level of oxygen were observed, and this entailed a change in the biosystem. Approximately 300 million years ago, its content in the atmosphere rose to 35%, while the planet was inhabited by insects. giant size. The largest extinction of living beings in the history of the Earth happened about 250 million years ago. During it, more than 90% of the inhabitants of the ocean and 75% of the inhabitants of the land died. One version of the mass extinction says that the low oxygen content in the air was to blame. The amount of this gas has dropped to 12% and it is in the lower atmosphere up to a height of 5300 meters. In our era, the oxygen content in atmospheric air reaches 20.9%, which is 0.7% lower than 800 thousand years ago. These figures have been confirmed by scientists from Princeton University who examined samples of Greenland and Atlantic ice formed at that time. The frozen water saved the air bubbles, and this fact helps to calculate the level of oxygen in the atmosphere.
What is its level in the air
Active absorption of it from the atmosphere can be caused by the movement of glaciers. As they move away, they reveal vast areas of organic layers that consume oxygen. Another reason may be the cooling of the waters of the World Ocean: its bacteria during low temperature take up more oxygen. The researchers argue that the industrial leap and with it the burning of a huge amount of fuel does not have a special impact. The world's oceans have been cooling for 15 million years, and the amount of vital matter in the atmosphere has decreased regardless of human impact. There are probably some natural processes, leading to the fact that oxygen consumption becomes higher than its production.
Human impact on the composition of the atmosphere
Let's talk about the influence of man on the composition of the air. The level that we have today is ideal for living beings, the oxygen content in the air is 21%. The balance of it and other gases is determined life cycle in nature: animals exhale carbon dioxide, plants use it and release oxygen.
But there is no guarantee that this level will always be constant. The amount of carbon dioxide released into the atmosphere is increasing. This is due to the use of fuel by mankind. And it, as you know, was formed from fossils organic origin and carbon dioxide is released into the air. Meanwhile, the most big plants of our planet, trees are being destroyed at an increasing rate. Kilometers of forest disappear in a minute. This means that part of the oxygen in the air is gradually falling and scientists are already sounding the alarm. The earth's atmosphere is not a limitless pantry and oxygen does not enter it from the outside. It has been developed all the time along with the development of the Earth. It must be constantly remembered that this gas is produced by vegetation in the process of photosynthesis due to the consumption of carbon dioxide. And any significant reduction in vegetation in the form of deforestation inevitably reduces the ingress of oxygen into the atmosphere, thereby disturbing its balance.
Air is natural mixture various gases. Most of all, it contains elements such as nitrogen (about 77%) and oxygen, less than 2% are argon, carbon dioxide and other inert gases.
Oxygen, or O2, is the second element of the periodic table and the most important component, without which life would hardly exist on the planet. He participates in various processes on which all living things depend.
In contact with
Composition of air
O2 performs the function oxidative processes in the human body, which allow you to release energy for normal life. At rest, the human body requires about 350 milliliters of oxygen, with severe physical activity this value increases three to four times.
What percentage of oxygen is in the air we breathe? The norm is 20,95% . Exhaled air contains less O2 - 15.5-16%. The composition of exhaled air also includes carbon dioxide, nitrogen and other substances. A subsequent decrease in the percentage of oxygen leads to a malfunction, and a critical value of 7-8% causes fatal outcome.
From the table it can be understood, for example, that exhaled air contains a lot of nitrogen and additional elements, but O2 only 16.3%. The oxygen content of the inhaled air is approximately 20.95%.
It is important to understand what an element such as oxygen is. O2 - the most common on earth chemical element which is colorless, odorless and tasteless. It performs the most important function of oxidation in.
Without the eighth element of the periodic table can't get fire. Dry oxygen improves electrical and protective properties films, to reduce their space charge.
This element is contained in the following compounds:
- Silicates - they contain approximately 48% O2.
- (marine and fresh) - 89%.
- Air - 21%.
- Other compounds in the earth's crust.
Air contains not only gaseous substances, but also vapors and aerosols and various contaminants. It can be dust, dirt, other various small debris. It contains microbes that can cause various diseases. Influenza, measles, whooping cough, allergens and other diseases - this is just a small list negative consequences, which appear when the air quality deteriorates and the level of pathogenic bacteria increases.
The percentage of air is the amount of all the elements that make up it. It is more convenient to show clearly what the air consists of, as well as the percentage of oxygen in the air, on the diagram.
The diagram shows which gas contains more in the air. The values given on it will be slightly different for inhaled and exhaled air.
Diagram - air ratio.
There are several sources from which oxygen is formed:
- Plants. Even from the school biology course, it is known that plants release oxygen when they absorb carbon dioxide.
- Photochemical decomposition of water vapor. The process is observed under the action solar radiation in top layer atmosphere.
- Mixing of air streams in the lower atmospheric layers.
The functions of oxygen in the atmosphere and for the body
For a person, the so-called partial pressure, which the gas could produce if it occupied the entire occupied volume of the mixture. The normal partial pressure at 0 meters above sea level is 160 millimeters mercury column . An increase in altitude causes a decrease in partial pressure. This indicator is important, since the supply of oxygen to all important organs and in depends on it.
Oxygen is often used for treatment various diseases . Oxygen cylinders, inhalers help human organs to function normally in the presence of oxygen starvation.
Important! The composition of the air is influenced by many factors, respectively, the percentage of oxygen can change. The negative environmental situation leads to a deterioration in air quality. In megacities and large urban settlements, the proportion of carbon dioxide (CO2) will be greater than in small settlements or in forest and protected areas. Altitude also has a great influence - the percentage of oxygen will be less in the mountains. We can consider the following example - on Mount Everest, which reaches a height of 8.8 km, the concentration of oxygen in the air will be 3 times lower than in the lowland. For a safe stay on high mountain peaks, you need to use oxygen masks.
The composition of the air has changed over the years. Evolutionary processes, natural disasters have led to changes in, therefore decreased percentage of oxygen required for normal operation bioorganisms. Several historical stages can be considered:
- prehistoric era. At that time, the concentration of oxygen in the atmosphere was about 36%.
- 150 years ago O2 occupied 26% from the total air composition.
- At present, the concentration of oxygen in the air is just under 21%.
The subsequent development of the surrounding world can lead to a further change in the composition of the air. It is unlikely for the foreseeable future that the O2 concentration could be below 14%, as this would cause disruption of the body.
What does lack of oxygen lead to?
Low intake is most often observed in stuffy vehicles, poorly ventilated rooms or at height . Decreased oxygen levels in the air can cause Negative influence on the body. The mechanisms are depleted the greatest influence exposed nervous system. There are several reasons why the body suffers from hypoxia:
- Blood deficiency. called in case of poisoning carbon monoxide . This situation lowers the oxygen component of the blood. This is dangerous because the blood stops delivering oxygen to hemoglobin.
- circulatory deficiency. It is possible with diabetes, heart failure. In such a situation, blood transport worsens or becomes impossible.
- Histotoxic factors affecting the body can cause the loss of the ability to absorb oxygen. Arises in case of poisoning or due to heavy exposure.
According to a number of symptoms, it can be understood that the body needs O2. First of all increased breathing rate. It also increases the heart rate. These protective functions are designed to supply oxygen to the lungs and provide them with blood and tissues.
The lack of oxygen causes headaches, increased drowsiness, deterioration in concentration. Isolated cases are not so terrible, they are quite easy to correct. To normalize respiratory failure, the doctor prescribes bronchodilator drugs and other drugs. If hypoxia takes severe forms, such as loss of a person's coordination or even a comatose state the treatment becomes more difficult.
If symptoms of hypoxia are found, it is important consult a doctor immediately and not to self-medicate, since the use of one or another medicinal product depends on the cause of the violation. Helps for mild cases oxygen mask treatment and pillows, blood hypoxia requires a blood transfusion, and the correction of circular causes is possible only with surgery on the heart or blood vessels.
The incredible journey of oxygen through our body
Conclusion
Oxygen is the most important air component, without which it is impossible to carry out many processes on Earth. Air Composition changed over tens of thousands of years due to evolutionary processes, but now the amount of oxygen in the atmosphere has reached the value at 21%. The quality of the air a person breathes affects his health therefore, it is necessary to monitor its cleanliness in the room and try to reduce environmental pollution.
Given in Table. 1.1 The composition of atmospheric air undergoes various changes in enclosed spaces. Firstly, the percentage of individual mandatory components changes, and, secondly, additional, uncharacteristic components appear. clean air impurities. In this paragraph, we will discuss changes in the gas composition and its permissible deviations from normal.
The most important gases for human life are oxygen and carbon dioxide, which are involved in the gas exchange of a person with the environment. This gas exchange takes place mainly in the human lungs during respiration. Gas exchange occurring through the surface of the skin is about 100 times less than through the lungs, since the surface of the body of an adult is approximately 1.75 m2, and the surface of the alveoli of the lungs is about 200 m2. The process of respiration is accompanied by the formation of heat in the human body in an amount of 4.69 to 5.047 (on average 4.879) kcal per 1 liter of absorbed oxygen (passed into carbon dioxide). It should be noted that only a small part of the oxygen contained in the inhaled air (approximately 20%) is absorbed. So, if in the atmospheric air there is approximately 21% of oxygen, then in the air exhaled by a person it will be about 17%. Typically, the amount of carbon dioxide exhaled is less than the amount of oxygen taken in. The ratio of the amount of carbon dioxide emitted by a person and the oxygen absorbed is called the respiratory coefficient (RC), which usually ranges from 0.71 to 1. However, if a person is in a state of strong excitement or performs very hard work, the ROC can be even greater than one.
The amount of oxygen necessary for a person to maintain normal life activity mainly depends on the intensity of the work performed by him and is determined by the degree of nervous and muscular tension. Assimilation of oxygen by the blood occurs best at a partial pressure of about 160 mm Hg. Art., that at atmospheric pressure 760 mmHg Art. corresponds to the normal percentage of oxygen in the atmospheric air, i.e. 21%.
Due to the ability of the human body to adapt, normal breathing can be observed even with smaller amounts of oxygen.
If the reduction in the oxygen content in the air occurs due to inert gases (for example, nitrogen), then a significant decrease in the amount of oxygen is possible - up to 12%.
However, in enclosed spaces, a decrease in the oxygen content is accompanied not by an increase in the concentration of inert gases, but by the accumulation of carbon dioxide. Under these conditions, the maximum allowable minimum oxygen content in the air should be much higher. Usually, the oxygen content equal to 17% by volume is taken as the norm for this concentration. Generally speaking, indoors, the percentage of oxygen never drops to this level, since the concentration of carbon dioxide reaches the limit value much earlier. Therefore, it is practically more important to set the limit allowable norms content in enclosed spaces is not oxygen, but carbon dioxide.
Carbon dioxide CO2 is a colorless gas with a weak sour taste and smell; it is 1.52 times heavier than air, slightly poisonous. The accumulation of carbon dioxide in indoor air leads to headaches, dizziness, weakness, loss of sensation and even loss of consciousness.
It is believed that in atmospheric air the amount of carbon dioxide is 0.03% by volume. This is true for rural areas. In the air large industrial centers its content is usually larger. For calculations, a concentration of 0.04% is taken. The air exhaled by a person contains about 4% carbon dioxide.
Without any harmful consequences for the human body, concentrations of carbon dioxide much higher than 0.04% can be tolerated in indoor air.
The value of the maximum allowable concentration of carbon dioxide depends on the length of stay of people in a particular enclosed space and on the type of their occupation. For example, for sealed shelters, when healthy people are placed in them for a period of not more than 8 hours, a norm of 2% can be taken as the maximum allowable concentration of CO2. With a short stay of people, this rate can be increased. The possibility of a person staying in an environment with elevated concentrations of carbon dioxide is due to the ability of the human body to adapt to different conditions. At a concentration of CO2 higher than 1%, a person begins to inhale significantly more air. Thus, at a CO2 concentration of 3%, respiration doubles even at rest, which in itself does not cause noticeable negative consequences during a relatively short stay in such air of a person. If a person stays in a room with a CO2 concentration of 3% for a sufficiently long time (3 or more days), he is threatened with loss of consciousness.
With a long stay of people in sealed rooms and when people perform one or another work, the value of the maximum allowable concentration of carbon dioxide should be significantly less than 2%. It can fluctuate from 0.1 to 1%. A carbon dioxide content of 0.1% can also be considered acceptable for ordinary non-pressurized premises of buildings and structures for various purposes. A lower concentration of carbon dioxide (of the order of 0.07-0.08) should be prescribed only for the premises of medical and children's institutions.
As will be clear from the following, the requirements for the content of carbon dioxide in the air of the premises of ground buildings are usually easily met if the sources of its release are people. Otherwise, the question is when carbon dioxide accumulates in industrial premises as a result of some technological processes occurring, for example, in yeast, breweries, hydrolysis shops. In this case, 0.5% is taken as the maximum allowable concentration of carbon dioxide.
atmospheric air, which a person inhales while outdoors (or in well-ventilated rooms), contains 20.94% oxygen, 0.03% carbon dioxide, 79.03% nitrogen. In enclosed spaces filled with people, the percentage of carbon dioxide in the air can be somewhat higher.
Exhaled air contains an average of 16.3% oxygen, 4% carbon dioxide, 79.7% nitrogen (these figures are given in terms of dry air, that is, excluding water vapor, which is always saturated with exhaled air).
Composition of exhaled air very fickle; it depends on the intensity of the body's metabolism and on the volume of pulmonary ventilation. It is worth taking a few deep breathing movements or, on the contrary, holding your breath so that the composition of the exhaled air changes.
Nitrogen does not participate in gas exchange, however, the percentage of nitrogen in visible air is several tenths of a percent higher than in inhaled air. The fact is that the volume of exhaled air is somewhat less than the volume of inhaled air, and therefore the same amount of nitrogen, distributed in a smaller volume, gives a larger percentage. The smaller volume of exhaled air compared to the volume of inhaled air is due to the fact that slightly less carbon dioxide is released than oxygen is absorbed (part of the absorbed oxygen is used in the body to circulate compounds that are excreted from the body with urine and sweat).
Alveolar air differs from exhaled by a large percentage of non-acid and a smaller percentage of oxygen. On average, the composition of alveolar air is as follows: oxygen 14.2-14.0%, carbon dioxide 5.5-5.7%, nitrogen about 80%.
Definition composition of alveolar air important for understanding the mechanism of gas exchange in the lungs. Holden proposed a simple method for determining the composition of alveolar air. After a normal inhalation, the subject exhales as deeply as possible through a tube 1-1.2 m long and 25 mm in diameter. The first portions of exhaled air leaving through the tube contain the air of the harmful space; the last portions remaining in the tube contain alveolar air. For analysis, air is taken into the gas receiver from that part of the tube that is closest to the mouth.
The composition of the alveolar air varies somewhat depending on whether the air sample was taken for analysis at the height of inhalation or exhalation. If you make a quick, short and incomplete expiration at the end of a normal inspiration, then the air sample will reflect the composition of the alveolar air after filling the lungs with respiratory air, i.e. during inspiration. If you take a deep breath after a normal exhalation, then the sample will reflect the composition of the alveolar air during exhalation. It is clear that in the first case, the percentage of carbon dioxide will be somewhat less, and the percentage of oxygen will be somewhat greater than in the second. This can be seen from the results of Holden's experiments, who found that the percentage of carbon dioxide in the alveolar air at the end of inspiration is on average 5.54, and at the end of expiration - 5.72.
Thus, there is a relatively small difference in the content of carbon dioxide in the alveolar air during inhalation and exhalation: only 0.2-0.3%. This is largely due to the fact that during normal breathing, as mentioned above, only 1/7 of the volume of air in the pulmonary alveoli is renewed. The relative constancy of the composition of the alveolar air is of great physiological importance, as will be explained below.
We all know very well that without air not a single one can live on earth. creature. 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 perfectly well that it is around us, although we practically do not notice it. To conduct research of a different nature, including, it is possible in our laboratory.
We can only feel the air when we feel strong wind or we are near the fan. What does air consist of, and 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 as a 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 life 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 that is needed for life is released. Also, oxygen, which is in the air, is also required for burning fuel, which produces heat, as well as when receiving mechanical energy in internal combustion engines.
Inert gases are also extracted from the air during liquefaction. How much oxygen is in the air, if you look at the percentage, then oxygen and nitrogen in the air is 98 percent. Knowing the answer to this question, another one arises, which gaseous substances are still part of the air.
So, in 1754, a scientist named Joseph Black confirmed that the air consists of a mixture of gases, and not a homogeneous substance, as previously thought. The composition of air on earth includes methane, argon, carbon dioxide, helium, krypton, hydrogen, neon, xenon. It is worth noting that the percentage of air can 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 how many percent of oxygen is in the air in the mountains. The answer is simple, oxygen is much heavier than nitrogen, so it will be much less in the air in the mountains, this is because the density of oxygen decreases with height.
The rate of oxygen in the air
So, with regard to 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 norm of oxygen in the air is from 19 to 23 percent. When operating equipment in enterprises, it is imperative to monitor the tightness of the devices, as well as various machines. If, when testing the air in a room where people work, the oxygen indicator 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 researching.
Let's now define what oxygen is.
Oxygen is chemical element According to Mendeleev's periodic table of elements, oxygen has no smell, no taste, no color. Oxygen in the air is essential for human respiration, as well as for combustion, because it is no secret to anyone that if there is no air, then no materials will burn. Oxygen contains a mixture of three stable nuclides, mass numbers which are 16. 17 and 18.
So, oxygen is the most common element on earth, with regard to the percentage of oxygen, the largest percentage is in silicates, which is about 47.4 percent of the mass of solid earth's crust. Also in marine 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 1500 compounds in the earth's crust.
As for the production of oxygen, it is obtained by separating air at low temperatures. This process occurs as follows, at the beginning they compress the air with the help of a compressor, while compressing the air, it begins to heat up. compressed air allow to cool to room temperature, and after cooling provide its free expansion.
When expansion occurs, the gas temperature begins to drop sharply, after the air has cooled, its temperature can be several tens of degrees lower than room temperature, such air is again subjected to compression and the released heat is taken away. After several stages of air compression and cooling, a number of procedures are performed as a result of which pure oxygen is separated without any impurities.
And here another question arises which 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, while the density of oxygen is 1.43 kg/m3. As for carbon dioxide, as it turns out, 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.
What is carbon dioxide?
Now let's define in more detail what carbon dioxide is, and also denote the composition of carbon dioxide. So, carbon dioxide in other words is carbon dioxide, it is a colorless gas with a slightly sour smell and taste. As for the air, the concentration of carbon dioxide in it is 0.038 percent. physical properties carbon dioxide is that it does not exist in liquid state at normal atmospheric pressure, and immediately passes from a solid to a gaseous state.
Carbon dioxide in the solid state is also called dry ice. To date, carbon dioxide is a participant global warming. They produce carbon dioxide by burning various substances. It is worth noting that at 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 soda water, and is also used in pneumatic weapons. And also in Food Industry as a preservative.
Composition of inhaled and exhaled air
Now let's analyze the composition of the inhaled and exhaled air. First, let's define what breathing is. Breathing is a complex continuous process by which the gas composition of the blood is constantly updated. The composition of the air we breathe is 20.94 percent oxygen, 0.03 percent carbon dioxide, and 79.03 percent nitrogen. But the composition of the exhaled air is already only 16.3 percent oxygen, as much as 4 percent carbon dioxide and 79.7 percent nitrogen.
It can be seen that the inhaled air differs from the exhaled one in the content of oxygen, as well as 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 to the outside.
Dry oxygen improves the electrical and protective properties of the films due to the absence of water, as well as their compaction and reduction of the space charge. Also, dry oxygen under normal conditions cannot react with gold, copper or silver. To spend chemical analysis air or other laboratory research, including, is possible in our laboratory "EkoTestEkspress".
Air is the atmosphere of the planet on which we live. And we always have the question of what is part of the air, the answer is simply a set of gases, as it has already been described above, which gases and in what proportion are in the air. As for the content of gases in the air, everything is easy and simple here, 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 to oxygen and other gases in the air. So, how much oxygen is in the air, the simple answer is only 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. A lot has already been said about oxygen, because it is of great importance for human life on our planet. It is worth noting that the inhalation of air with increased oxygen by a person in a short period does not adversely affect the person himself.
But if a person breathes air with increased level oxygen for a long time, it will lead to pathological changes in the body. Another main component of the air, about which much has already been said, is carbon dioxide, as it turns out, a person cannot live without it as well as without oxygen.
If there was no air on earth, then not one living organism could live on our planet, much less function somehow. Unfortunately, in modern world great amount industrial facilities that pollute our air recent times increasingly calling for what needs to be protected environment and keep the air clean. Therefore, frequent air measurements should be taken to determine how clean it is. If it seems to you that the air in your room is not clean enough and there are external factors to blame, you can always contact the EcoTestExpress laboratory, which will conduct everything necessary tests( , research ) and will give a conclusion about the purity of the air you breathe.
