What did I use to find air? How do you know that air is there?

In this case, you can use some gas detectors and you can achieve a very good result without any problems.

Of course, man discovers air with his own breath, because without air, he cannot breathe.

Oh, you can make a plastic bag, you can seal the plastic bag, and then squeeze it, pinch it, and you'll find out, but it's air in it.

Hello friends, you can use a balloon to blow the heat inside, so that you can feel the presence of air.

Finding air, I think there should be a lot of ways to do it, we breathe every day, you can hold your breath and then inhale loudly. You'll be able to see the air running inside your organs.

I think if you take a plastic bag and move it to the air, it will fill with air, so that you can find the air.

Fill a plastic bag with air and compress the plastic bag to find that the air cannot be pressed inside.

We breathe every day, so I feel the air, the air is moving, and if you're in a sealed space, you're going to feel the air, otherwise you're holding your breath.

Air is a matter of common sense that has been discovered by scientists and has been researched.

The term air has been coined for a long time, especially in chemistry.

1. Put the cup upside down in the water, and then tilt the cup to see bubbles coming out of the cup, proving that air is there.

2. If you stare the cup upside down in the water, the water cannot enter the cup, which proves that the air in the cup exists, and in the case of air, the water cannot enter the cup.

3. The rotation of the windmill can also feel the presence of the surrounding air.

4. Put the sponge into the water and squeeze it to produce bubbles to prove the existence of air.

5. Fill the sink with a beverage bottle and see bubbles bubble to prove the existence of air.

6. Today's aircraft are like *** and fixed-wing aircraft, and they can't fly without air.

7. Use a suction cup to suck a smooth object, displace the air in the suction cup, and the suction cup is tightly adsorbed on the object due to the action of atmospheric pressure, and the existence of air is inferred.

8. The air is the medium for spreading sound, put an alarm clock in the bell-shaped cover, pull out the air in the cover, and the sound of the alarm clock gradually decreases to the point that it is inaudible, which proves the existence of air.

9. Fill half a bottle of water with a gas bottle, plug the bottle mouth and put it upside down, the water will not flow to the bottle mouth, which can prove the existence of air.

10. Find an empty beer bottle, put the vertical water side of the bottle mouth downward, and put it in the water until the water submerges the whole bottle, if the process is well controlled, there will be no bubbles coming out of the side, and there will be no water entering (note that it should be vertical, if it is tilted, there will be bubbles), which means that the air exists so the water cannot enter.

After the formation of the primitive atmosphere, green plants appeared, and green plants photosynthesized and produced long-lasting oxygen, and finally formed the current air. Air is the gas that makes up the atmosphere around the earth. It is colorless and odorless, and the main components are nitrogen and oxygen.

Air refers to the mixture of gases in the Earth's atmosphere. It is mainly composed of 78% nitrogen, 21% oxygen, and 1% rare gases and impurities. The composition of the air is not fixed by the solid section, and the composition ratio of the air will also change with the change of altitude and air pressure.

1. The air is directly invisible, intangible, colorless, odorless and transparent gas.

An ordinary plastic bag can be prepared. Tie the bag tightly with your hand. You can see the pockets bulging. It's air.

2. Occupy space.

Place a plain napkin in a beaker. Then place the beaker upside down in the sink and submerge it all. Take it out, why is this piece of paper not wet?

It turned out that the beaker was filled with air, and the air took up the space, providing a dry environment for the paper.

3. It will flow.

One beaker is filled with air and the other is filled with water. When we tilt the beaker filled with air, since the air is lighter than the water, the air will flow upwards into the water-filled beaker above, and the water will be driven out. Air flows upwards in water.

4. Air is easily compressed.

With a regular syringe, draw in air and water respectively, then plug the nozzle with your fingers, and press the piston with the same size and pull the piston upwards.

The space occupied by air can be compressed or enlarged, it has no fixed shape and volume.

5. Air has a certain weight.

Two air-filled balloons are placed on both sides of the lever ruler to balance, and when one pilling is punctured, the balance is disrupted. Explain that air has weight.

Air is formed by changes in the original atmosphere. The main components of the atmosphere of the primitive earth are methane, water vapor, ammonia, hydrogen sulfide, etc., and later due to volcanic eruptions, the emergence of organisms, and the emergence of plants, the current air was gradually formed, and its main components are about 78% nitrogen, 21% oxygen, and other components such as carbon dioxide.

It is layered on the earth's surface, transparent and colorless and odorless, it is mainly composed of nitrogen and oxygen, and has an important impact on human survival and production.

Air is a mixture of gases in the Earth's Great Cracked Gas Layer, which is mainly composed of nitrogen, oxygen, noble gases (helium, neon, argon, krypton, xenon, radon), carbon dioxide and other substances (such as water vapor, impurities, etc.). Among them, the volume fraction of nitrogen is about 78%, the volume fraction of oxygen is about 21%, the volume fraction of noble gases (helium, neon, argon, krypton, xenon, radon) is about, the volume fraction of carbon dioxide is about, and the volume fraction of other substances (such as water vapor, impurities, etc.) is about. The composition ratio of air varies with altitude and air pressure.

Historically, humans thought that air was a single substance, until the French scientist Lavoisier first came to the conclusion that air is composed of oxygen and nitrogen through experiments. At the end of the 19th century, scientists discovered through a large number of experiments that there were rare gases such as helium, argon, and xenon in the air.

Air: In its natural state, air is colorless and odorless. Oxygen in the air is necessary for all aerobic organisms. All animals need to breathe oxygen, as do the respiration of green plants.

In addition, green plants use carbon dioxide from the air for photosynthesis, and air is almost the only carbon dioxide required by all plants**.

Air is a mixture of many gases. Its constant components are oxygen, nitrogen, and noble gases, and its variable components are carbon dioxide and water vapor, and their levels in the air vary slightly depending on geography and temperature. As for the indefinite components of the air, it varies from region to region, for example, sulfur dioxide is contained near metallurgical plants, chlorine is found near chlor-alkali plants, and so on.

In addition, there are trace amounts of hydrogen, ozone, nitrous oxide, methane and, to a lesser extent, dust in the air.

Air is the gas that makes up the atmosphere around the earth. Colorless, odorless, the main components are nitrogen and oxygen, as well as a very small amount of radon, helium, neon, argon, krypton, xenon and other rare gases and water vapor, carbon dioxide and dust. Air at room temperature is a colorless and odorless gas, while liquid air is a light yellow liquid that flows easily.

Generally, when the air is liquefied, the carbon dioxide has been removed, so the composition of the liquid air is oxygen, nitrogen and argon, and the content of other components is very small, which can be omitted.