Physical properties
- Temperature. Regulates heat exchange.
- Humidity. Determines the saturation of gases with oxygen and the content of water vapor.
- Atmosphere pressure. The mass of the atmospheric column that presses on the surface of the planet and on everything located inside the ocean of air.
- Mobility. Forms winds and renewal of gas composition.
- Solar radiation. Determines the percentage of radioactive substances and gases contained in the atmosphere. The main indicator of the formation of the planet's climate.
- Electrical activity. The amount of electrical charges contained in the air space.
What is air?
Air is a mixture of various gases: oxygen, nitrogen, carbon dioxide, argon and water vapor. However, the most important component of air, without which life on the planet would be impossible, is oxygen.
The composition of air is influenced by two main factors:
- Height above sea level. As you climb the mountain, the amount of oxygen in the air will decrease more and more.
- Features of the area. In large cities, the amount of carbon dioxide is much higher than in a clean forest.
Rice. 1. The air in the forest is the cleanest.
Clean air is colorless and odorless.
One of the most serious environmental problems in the modern world is air pollution. A large number of cars, factories and factories greatly pollute the atmosphere with toxic substances. People living in cities are forced to breathe this poisonous gas. To solve this problem, it is necessary to introduce powerful treatment facilities into production.
Rice. 2. Air pollution.
Chemical composition of air
The air envelope of the Earth is formed from a mixture of gases:
- Nitrogen. The main component of the atmosphere. Does not participate in respiration, does not support combustion. Provides vital activity for algae and some plants.
- Oxygen. A vital element. It is necessary in the formation of biological processes in animal and plant organisms. Serves as an oxidizer and the main component of combustion of substances.
- Carbon dioxide. Absorbed by trees and converted into oxygen.
The atmosphere contains ozone, hydrogen, neon, and other gases in small quantities. The purity of the air is determined by the amount of harmful impurities. Read more in the article on air composition.
How do people use the properties of water?
Man has long learned to use the power of air as a source of energy. He invented the sail , which allowed him to travel.
Already 2-3 thousand years ago, the Egyptians sailed the Mediterranean Sea on quite advanced sailing ships.
In the Middle Ages, wind wheels for household work.
However, even in modern times, the wind engine plays an increasingly important role, since, unlike other sources, it does not pollute the atmosphere.
One way to travel through the air is a balloon filled with lighter-than-air gas or simply heated air. The beginning of the era of aeronautics should be considered the year 183, when the Montgolfier brothers took to the air in a hot air balloon.
You can’t rely on water reliably—it’s liquid. However, a water skier can do this if he develops sufficient speed. Air is even less dense than water. But if you develop high speed, then it turns out you can rely on it. This discovery made it possible to create more advanced aircraft.
The ability of aircraft to move through the air is due to the fact that air has a buoyant force. For example, if you fill a balloon with a lighter gas - hydrogen, then they will fly upward.
A parachute can glide through the air due to the density of the air.
You know that when water is heated it turns into steam, a gaseous state, and if the steam is cooled, it turns into a liquid state again.
It turns out that any gas can also be turned into a liquid if it is cooled. Only this will require a very low temperature.
Carbon dioxide, cooled to a solid state, is used to freeze food and is called dry ice. And it melts at -78 degrees C.
Liquid nitrogen is formed at a temperature of -196 degrees C. It is used in medicine.
Pure oxygen is used for breathing of patients. They fill scuba tanks for underwater breathing. There are oxygen masks on planes for emergencies.
And liquid oxygen is needed to oxidize spacecraft fuel. After all, without oxygen, not only breathing is impossible, but also combustion.
We all understand that our planet simply needs air. It should be protected!
Verification work
Thermal conductivity of air
The surrounding air practically does not conduct heat. The ability to retain a thermal charge is widely used by humans and animals. By limiting the mobility of the flow, the air layer delays the heat exchange of organisms and creates a comfortable microclimate.
When heated, air expands and rises, becoming rarefied. Its chemical composition and humidity change. Water vapor breaks down into separate gases and becomes more volatile.
As the air cools, it compresses and it sinks. A small amount of solid particles in gases is oxidized and saturated with water vapor. The air becomes heavier and denser.
What is air needed for?
An ocean of air surrounds the Earth, filling the voids and the tiniest crevices. It is even found in water, only in dissolved form.
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Air performs very important functions:
- All living organisms need air to breathe. Thanks to the respiratory processes, the body of people and animals is saturated with energy and nutrients, and all vital processes are activated. Without air, plants would not be able to breathe and form nutrients.
A person can live without food for several weeks, without water for several days, and without air for only a few minutes. If you try not to breathe for some time, then within a few seconds you will have a strong desire to take a deep breath. Without air there is no life!
- Air movement, which is associated with uneven heating, determines the climate in different regions. Land areas far from the seas and oceans are saturated with moisture brought by the winds.
Rice. 3. Formation of clouds and clouds.
- The vast air space provides reliable protection from dangerous solar radiation and cosmic cold.
- Thanks to air, we can make and hear sounds. Sound is a wave that can be transmitted over a distance only under atmospheric conditions. For example, there is no atmosphere on the Moon, and absolute silence reigns there.
The air “blanket” is held in place by the forces of gravity. If for some reason the globe was left without an atmosphere, it would very quickly turn into a lifeless desert.
Application and use of air properties
The air envelope of the planet is actively used by animals and birds. The ability to retain heat helps animals survive and regulate the body's thermal processes. The wool of the inhabitants of northern latitudes has a hollow structure.
Birds use the special structure of the feather and the movement of air masses for flight and gliding above the ground.
A bubble filled with atmosphere holds fish in the water column and facilitates movement from the depths of reservoirs to the surface.
Motility is used by plants for pollination and dispersal of seeds over large areas.
Man uses the properties of the atmosphere in a wide range of his life activities:
- Thermal conductivity provides heating and thermoregulation of the body.
- The ability of warm air currents to rise is used in flight.
- Elasticity and compression are used in all industrial systems. It is pumped into car tires. Pneumatic tools and weapons work by pumping up air pressure.
- Oxygen is involved in combustion processes. All internal combustion engines consume large volumes of oxygen and its compounds.
More information about the use and importance of air by living organisms here.
check yourself
What gas do we absorb from the air when we breathe?
When we breathe, we take in oxygen and exhale carbon dioxide.
List the properties of air.
The air is colorless, transparent, and odorless. When heated, it expands. And when cooled it contracts.
Why does air expand when heated and contract when cooled?
When heated, air particles move faster, collide harder and fly apart over longer distances, and when cooled, the opposite happens.
Why is the air polluted?
The air is polluted as a result of human activities. From industrial emissions from enterprise pipes, from exhaust gases from car engines.
What should be done to protect air purity?
To protect air, it is necessary to install air purification systems at industrial enterprises and prohibit the use of cars running on gasoline and oil products.
Comparison of the properties of water and air
The ocean of air plays a major role in the breathing of all living creatures on Earth. Its content in water is used by all underwater animals and plants.
Water and air have similar parameters. It is also transparent and tasteless, and reacts to heating and cooling in the same way. The main difference between water is its ability to dissolve substances and its high density. Water has a large mass and thermal conductivity, conducts electrical charges. The ability to extract the necessary components from water, without the use of special equipment, is beyond the power of humans and mammals.
Conditions of water
Everyone is accustomed to the fact that water is a transparent liquid, without color or taste. However, it can be in three states :
- liquid;
- hard (ice);
- gaseous (water vapor).
The state of water directly depends on temperature. If it’s warm outside, then the water is liquid; in extreme cold (less than 0C), the water freezes and turns into ice, and when it boils (more than 100C), it begins to evaporate into the air.
Rice. 1. Ice.
The ability of water to change its state under the influence of temperature explains such an important process as the water cycle in nature.
One of the important properties of liquid water is its ability to dissolve many substances. Various crystals (salt, sugar), alkali (soap) easily dissolve in water. But, say, she can’t cope with oil or stones.
