The air surrounds us every day, but we do not notice it, although we cannot live without it. How much do you know about air? Put yourself to the test and read NASA's compilation of fun facts about air.
1. Air is mostly gas
The air is around us, but we do not see it. So what is air? It is a mixture of different gases. The air in the Earth's atmosphere is composed of approximately 78% nitrogen and 21% oxygen. There are also small amounts of other gases in the air, such as carbon dioxide, neon and hydrogen.
2. Air is not only gas
Although air is mostly gas, it also contains many tiny particles. These airborne particles are called aerosols. Some aerosols - such as dust and pollen - enter the air naturally when the wind blows. But air also carries particles that cause pollution - soot, smoke, and pollutants from the exhaust gases of cars and power plants. When there are too many of these particles in the air, it is difficult for plants and animals to breathe.
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3. Air is important for all living things
People, animals and plants need to breathe. During breathing, living creatures take oxygen from the air and exhale carbon dioxide. This process gives animals and plants the energy to eat, grow and live.
4. Carbon dioxide in the air can be both good and bad
When people and animals breathe, an odorless gas - carbon dioxide (CO2) - is released into the air. Plants use this gas, along with sunlight, to produce food. This process is called photosynthesis. During this process, plants also release oxygen. However, large amounts of CO2 are produced when cars and power plants burn coal, oil and gasoline. CO2 is the biggest culprit in anthropogenic global warming.
5. Air contains water
Humidity is usually measured as a percentage, so the highest RH level just before rain is 100%. Humidity is measured with a psychrometer.
6. The air changes as you go higher
The air seems light, but it presses strongly against the surface of the Earth. This is called atmospheric pressure. At sea level, atmospheric pressure is high, as the atmosphere weighs down with all its weight. At the top of the mountain, the air presses less and the pressure is low. Due to the change in pressure, your ears clog when you take off in an airplane or drive up a hill.
7. Air - protective cushion
The air in our atmosphere acts as thermal insulation, saving the Earth from hypothermia and overheating. Ozone protects us from sunlight. Air in the atmosphere - protection from meteoroids. When meteoroids come in contact with the atmosphere, they rub against the air and burn, breaking apart into small pieces.
8. There is life in the air
Many living things live in soil and water. But living organisms can also live in the air. These tiny microbial organisms are called bioaerosols. Although these microbes cannot fly, they travel long distances in the air - by wind, rain, or simply sneezing!
9. Air can move quickly and far
Even on a very calm day, the air moves around us. But when a strong wind begins to blow, we ourselves see that the air starts to move. The strongest gust of wind reached a speed of 400 km / h. When the wind picks up seeds, dust and other particles, it can carry them miles from their home.
10. Air pollution can cancel a picnic
Air pollution is measured by the Air Quality Index. The lower the indicator, the cleaner the air. However, if you are outdoors when the index is above 100, you get the same level of pollution as if you were breathing the exhaust fumes of a car all day. The reasons for this poor air quality are forest fires and cars. If the index is above 100, you shouldn't spend too much time outside the home.