Air is a transparent, colorless gas. The air is everywhere and fills all the cracks. For example, outwardly an empty glass is not at all empty, because it is filled with air to the edges. In addition to books, the book shelf also contains air, the school portfolio among textbooks and notebooks also “hid” air, even between the pages of the class magazine is located. The air surrounds our planet with a dense shell called the atmosphere.
The thickness of the atmosphere reaches 20,000 km. But any layer of the atmosphere contains a different amount of air. In the troposphere, the lower layer of the atmosphere, the air is dense, thick, although we do not feel it at all. If we rise above, then we will feel that it became more difficult for us to breathe, it seems not enough air. This is because the air is no longer so dense at the height. So the density of the atmosphere gradually changes, and it goes into the cosmic vacuum. Look at the oxygen concentrator Moscow here.
You can feel the air? Of course, you can do it very easy. Take the newspaper, and wave it in the direction of the face. What did you feel? This air affectionately touched your face. You probably often do this in the summer when you are hot, but you don’t think that the air helps you cool down. It is also easy to do. This requires rubber pear. If you bring the hole of the rubber pear to the ear and press the ball of the pen, you will hear the sound. This is the air.
You can see the air? How can it be seen when it is transparent and has no color? But how. Take a glass half filled with water and a straw for drinks. Perch the straw into the water and blow in that of its tip that is on the surface. What did you see? You saw transparent balls rise from the opposite tip of the straw to the surface of the water. These are balls of air.
“Why does the air rise to the surface of the water?» – you ask. But because the air is lighter than water, so its water pushes it. (By the way, for this reason, a small nail drowns in the water, and the giant-coorabread rests on its surface, because, inside, the ship contains a lot of air.)