I make a popular science video and all the emperors learn from it!

[Popular science continues.] 】

[Popular science on the earth, the ten most precious natural resources!]

[Second place: air resources.] 】

Air is the gas surrounding the earth. 】

[It covers the surface of the earth in layers, 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 atmosphere. 】

[It 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 rare gases (helium, neon, argon, krypton, xenon, radon) is about 0.934%, the volume fraction of carbon dioxide is about 0.04%, and the volume fraction of other substances (such as water vapor, impurities, etc.) is about 0.02%. 】

[The composition ratio of air varies with height and pressure. 】

[Air at room temperature is a colorless and odorless gas, while liquid air is a light blue liquid that flows easily.] 】

28【......】

[Physical Layering:]

[The air is wrapped around the outside of the earth, and the thickness reaches thousands of kilometers. 】

[This layer of air is called the atmosphere.] 】

The atmosphere is divided into the troposphere, stratosphere (stratosphere), mesosphere, ionosphere (warm layer), and fugitive layer. 】

Humans live in the troposphere. In the stratosphere, the air is much thinner, and here there is a gas called ozone, which absorbs the harmful ultraviolet rays from the sun's rays. 】

[The mesosphere, also known as the mesosphere, is the atmosphere from the top of the stratosphere to between 85 km.] 】

[Above is the ionosphere, where the air is in a state of partial or complete ionization, the ionosphere is a partially ionized atmospheric region, and the completely ionized atmospheric region is called the magnetosphere. 】

The role of the ionosphere is very important, it can reflect radio waves around the world. Excluding water vapor, carbon dioxide and various hydrocarbons, the average composition of the air from the ground to an altitude of 10 km remains constant. Ozone levels increased at an altitude of 25 km. At higher altitudes, the composition of the air varies with altitude and is clearly related to the time of day and solar activity. 】

【......】

[Research History:]

Historically, humans thought that air was a single substance. 】

[Until the 18th century, the scientist Lavoisier (1743~1794) determined the composition of the air by quantitative tests. 】

[He heated a small amount of mercury in an airtight container for 12 days, and found that some of the mercury turned into a red powder, and at the same time, the volume of air was reduced by about 1/5. 】

[Through the study of the remaining gas, he found that this part of the gas cannot provide breath and does not support combustion. 】

[He mistakenly thinks it's all nitrogen.] 】

[Lavoisier collected the red powder from the heating and reheated it in a smaller container to obtain mercury and oxygen, and the volume of oxygen was exactly equal to the volume of air reduced in the closed container.] He introduced the oxygen into the previous container, and the resulting gas had exactly the same properties as air. 】

[Through experiments, Lavoisier concluded that air is composed of oxygen and nitrogen, of which oxygen makes up 1/5.] 】

[Before the 19th century, it was believed that there was only nitrogen and oxygen in the air. 】

[It wasn't until 1892 that the physicist Reilly discovered that there was always a slight difference between the density of "nitrogen" obtained by separating oxygen from the air and the density of nitrogen obtained by decomposing nitrogen-containing substances. 】

[Reilly did not let go of this slight difference, and he later cooperated with Ramsay, a chemist in the country, and finally discovered that there is still a chemically inactive inert gas in the air - argon. 】

[In the following years, Ramsey and others successively discovered helium, neon, xenon, krypton, and radon, these six rare gases. 】

[It is now possible to accurately measure the composition of the air.] 】

【......】

【The role of air:】

[Because of the strong attraction of the earth, 80% of the air is concentrated in an average area of 15 kilometers above the ground.] 】

[This layer of air has a great impact on human life and production activities. 】

[When people talk about air pollution, they mean air pollution in this area. 】

Air is a necessary condition for the survival of animals and plants on the earth. 】

[Animal respiration and plant photosynthesis are inseparable from the air; the atmosphere can keep the temperature on the earth relatively stable, if there is no atmosphere, the temperature will be high during the day and low at night; the ozone layer can absorb ultraviolet rays from the sun and protect the organisms on the earth from harm; the atmosphere can prevent high-energy particles from space from entering the earth too much, and prevent meteorites from hitting the earth, because meteorites can slow down and burn when they rub against the atmosphere; wind, clouds, rain, Snow is formed by the atmosphere, sound is transmitted by air, and parachutes, parachutes and airplanes are all made use of the force of air. 】

【......】

Tang dynasty.

Li Shimin seemed to have fallen into an evil spirit, waving his two arms in front of him.

He wanted to touch the "air" and try to verify its existence.

This move. (If you read a violent novel, go to Feilu Novel Network!)

But it frightened the surrounding ministers.

"Your Majesty, Your Majesty!

"Your Majesty, he's evil!"

"Your Majesty, you can't be okay..."

Listen to the loud shouts of the ministers around me, mixed with the sound of crying and sobbing.

On Li Shimin's forehead, three black lines appeared on the straight 510!

"Shut up! "

Everyone else is going to be numb.

I just wanted to touch the air, and I was regarded as evil by the ministers.

"Your Majesty, it's all right, that's great. "

"Heaven has mercy!"

"Your Majesty, you don't have anything to pretend to be sick, but you can scare us miserably. "

“..."

The black line on Li Shimin's forehead is even more obvious.

"I told shut up. "[]

Qing Dynasty.

Emperor Yongzheng stared at the light curtain suspiciously.

He couldn't figure it out.

Is there really something around me, these things that can't be seen or touched??

However, he quickly linked several common phenomena in life with the popular science of light curtains.

"If a person is strangled by the neck, he will die, is it blocking the air from entering the human body?"

"The usual wind, but also the air moving?"

“..."

The more Yongzheng thinks about it, the more he feels that his guess is reliable!

He was overjoyed.

If the Qing Dynasty can do some new research on the air, not to mention washing away the shame of the Qing Dynasty, at least it will be able to let future generations take a look at it.

Yongzheng's face was full of excitement, and he shouted: "Quickly get a clay pot and mercury, I want to verify it myself!"