What the air consists of. What gases does air consist of?
Our Earth is protected by an amazing shell -atmosphere. It prevents the fall of the cosmic bodies onto the planet and is one of the main conditions of human life. What does air consist of and why is it so important for animals and plants that exist on Earth? The answers to these and other questions can be found in this article.
What structure does the atmosphere have?
The Earth's air shell consists of several layers that have distinctive features.
- Troposphere. This is the lowest and densest layer of the atmosphere. 80% of the air is concentrated in it. Its thickness varies depending on the location: in the equator it is larger than above the poles. It is here that the weather is formed, fog and clouds are formed. The maximum thickness of the troposphere reaches 17 kilometers.
- Stratosphere. In this layer, at an altitude of 50 km, the temperature changes with altitude are reversed, rather than in the troposphere - it rises. Here is the ozone layer and contains a minimum number of water molecules. In the stratosphere at an altitude of 20 kilometers an ozone layer is formed.
- Mesosphere. Here, clouds are formed that consist of ice crystals, and a decrease in air density is observed. The mesosphere is located at a distance of 80-85 kilometers from the surface of the earth and has a temperature of minus 90 degrees Celsius.
- Thermosphere. Here, as a result of the collision of air particles with cosmic rays, a special glow arises, called "polar aurora". This layer also has a maximum temperature in the atmosphere - plus 1500 degrees Celsius.
- Exosphere. It extends to an altitude of 20,000 kilometers and is also called the "crown of the earth" because of the scattered form of its borders.
What substances does air consist of?
It should be noted that the atmosphere on the planetwas formed a long time ago. But in the time of the youth of our Earth, it consisted mainly of the products of the life activity of volcanoes. Only with the spread of the first plants on it the air began to be enriched with oxygen, which made it suitable for breathing people. Many planets of the Solar System have an atmosphere. But the composition that is suitable for human and animal life is only ours. At present, the main proportion of air in the atmosphere consists of two main gases: nitrogen and oxygen. As a percentage, the content of these substances is as follows: 78:21. Finding out what gases the air consists of, it is necessary to indicate the composition of that one percent that remains after subtracting the sum of the main gases from 100%. In the atmosphere, along with nitrogen and oxygen, contains carbon, hydrogen, inert gases, water vapor and other impurities. Oxygen is one of the main conditions of life for humans and animals, but carbon is essential for plants.
Is there water in the air?
Along with the gases, there is also water vapor in the air,which, depending on the height, can also be in the form of crystals. The content of this substance in air under certain conditions leads to the formation of fog and clouds. The total volume of atmospheric water on our planet is 14,000 cubic kilometers. By the way, the weight of air directly depends on the amount of water vapor contained in it. The more of them, the easier the air, since the air is heavier than them.
What impurities can be in the air of big cities?
Harmful gases enter the atmosphere during combustioncoal, gasoline, chemicals and artificial materials. As a result of the spread of road, rail and other modes of transport, as well as the activities of industrial enterprises, air is polluted by extraneous impurities. What does air in a big city consist of? Not only from substances such as carbon, oxygen and nitrogen, but also from carbon monoxide, methane and sulfur dioxide, which cause irreparable harm to the Earth's biosphere.
For example, if the air contains more3% carbon dioxide, this can cause the death of a living organism, since the norm is 0.03%. A large number of smoke, gases and soot that are contained in a polluted atmosphere, called "smog". It envelops many industrial areas and large cities on Earth.
How is acid rain formed?
The formation of such precipitates can be explained by knowingstructure of the composition of the atmosphere. From what molecules does the air consist? It is a gas mixture and water vapor. It contains molecules of water and other substances. When foreign impurities enter the atmosphere, the atoms of these components combine with water, turn into acid and fall to the ground. Such rains cause great damage to plants, animals and humans and are a real environmental disaster.
What is the ozone layer and where is it located?
It is formed in the stratosphere, at a distance of 20kilometers from the Earth. The ozone layer protects the biosphere of our planet from harmful ultraviolet radiation. It also neutralizes the effect of many harmful substances and bacteria. What does air in the ozone layer consist of? It contains active oxygen, which is formed as a result of the impact of electrical discharges or sunlight on the molecular. The release of methane, chlorine, bromine and nitrogen oxide contained in air conditioners and cooling plants into the atmosphere leads to the destruction of this layer, which is one of the global environmental problems of civilization.
What does atmospheric air consist of?
Composition of air, given in the article, is typicalOnly for the lower layer of the atmosphere, which is called the "troposphere." The farther from the surface of the earth, the more changes in it occur. What is the composition of air in the upper atmosphere? The first changes occur in the ozone layer - active oxygen appears. Further, at a distance of 1,000 km and more from the surface of the Earth, the predominance of atomic hydrogen and helium begins. With the altitude, the pressure also changes - it decreases, as the air becomes more discharged.
What pollutes the atmosphere?
The worse the ecological situation in the area, themore foreign matter is contained in the air and the more dangerous it is for the life of man and animals. With the development of civilization, the negative impact on the air envelope of the Earth has greatly increased. Industrial enterprises, automobile and railway transport, innovative goods of civilization (air conditioners, cooling plants, etc.) pollute the surrounding area, which leads to a decrease in the ozone layer, the formation of smog and acid rains.
Today the whole world prefersenvironmentally friendly technologies and transport, but a complete transition to such production will require a certain amount of time and large material costs and will last quite a long time.
30 years ago we were surprised when we heard aboutThe fact that in Western countries they sell simple drinking water in bottles. Today, any resident of a large city, more or less concerned about his health, will not drink what is flowing from the tap in our apartments. Acquisition of water for quenching thirst and cooking has become the norm.
In major cities in China, the sale of cleanair in tin cans. And earlier such facts were described only in fantastic stories. What the air consists of today depends on each earthling. Anyone can do a lot for the environment, following simple rules every day: do not wash the car in natural reservoirs, put out fires in time, quit smoking, start burning garbage and foliage in specially designated places, etc. After all, it is very important for us to know what air our descendants will breathe on Earth! And will they breathe ...