How can you tell if a gas is lighter or heavier than air?

Method: By comparing the relative molecular mass of the air with that gas.

The relative molecular mass of the two is 28 and 32, nitrogen accounts for about 78% and oxygen in the air, and the relative molecular weight of the air is calculated to be 29. When the relative molecular mass of the gas is greater than 29, it is heavier than air, and less than 29, it is lighter than air.

The relative molecular mass is the ratio of two masses, and the meaning of "relative" is further clarified in the computational expression form. In the definition, "specific unit" mainly refers to a special mixture whose composition such as air remains basically unchanged.

their relative quality.

Its average mass can be calculated based on the relative molecular mass of its constituent components (n, o, co, ar, etc.) and its volume fraction in air, which is then compared with the atomic mass.

1 to 12 can be obtained. The quantity symbol for the relative molecular mass is mr

The unit is "1".

Lighter than air:

Hydrogen Nitrogen Carbon Monoxide Helium Neon Methane Acetylene Ethylene is heavier than air:

O2, CO2, argon is basically just a few.

It can be compared to density: air – ammonia – hydrogen – large heavy, small light.

Relative molecular weights can also be compared.

Gases with a relative molecular mass greater than 29 are heavier than air, and those less than 29 are lighter than air.

Because the average relative molecular mass of air is 29!!

Hope!!!

Look at the relative molecular mass, for example, hydrogen, is 2, the air is about 29 is smaller than the air, so it floats above the air, and carbon dioxide is 12 + 16 2 44 is heavier than the air, so it is below the air.

The relative mass of air is 29, and the relative molecular mass of a gas is calculated compared to 29, and if it is larger, it is denser than air, and vice versa, it is smaller.

Calculate the molecular mass of the gas, the average molecular mass of the air is calculated as 29.

1. One balloon is inflated, and the same other is not inflated, and placed on both sides of the scale; You know that the air has weight, and the inflated side is heavy.

2. Tie the balloon with a rubber band, let the balloon go vertically, and then measure the length of the rubber band with a ruler; Then inject air into the balloon, also tie it with rubber and go vertically downward, measure the length, the latter method measures the length of the rubber band longer than the previous one, indicating that the air has mass.

3. Fill enough air in two plastic bottles, close the caps, and place them at both ends of the balance to balance the scale. If the lid of one of the bottles is opened, the air in this bottle decreases, and the balance is unbalanced, proving that the air also has mass.

The material composition of the atmosphere. The earth's atmosphere has constant gas components such as nitrogen, oxygen, and argon, gas components such as carbon dioxide and nitrous oxide, which are relatively fixed in content, and highly variable gas components such as water vapor, carbon monoxide, sulfur dioxide, and ozone. Solid and liquid aerosol particles such as dust, smoke particles, salt particles, water droplets, ice crystals, pollen, spores, and bacteria are often suspended.

The specific components are: nitrogen ( oxygen ( argon ( water vapor (carbon dioxide ( neon ( helium ( methane ( krypton ( hydrogen ( xenon ( ozone ( other (

The heaviest gas should be radon in the noble gas with a relative atomic mass of 222

The lightest gas should be hydrogen in a noble gas with a relative atomic mass of 2

Air is mainly composed of a mixture of 78% nitrogen, 21% oxygen, and many noble gases and impurities. The composition of air is not fixed, and as the altitude changes, the air pressure changes, and the proportion of air composition also changes.

The composition (volume ratio) of the Earth's atmosphere

Name Volume %

Nitrogen (N2).

Oxygen (O2).

Water vapor (H2O).

Argon (AR).

Carbon dioxide (CO2).

Helium (HE).

Neon gas (Ne).

Methane (CH4).

Krypton (kr).

Sulfur dioxide (SO2).

Hydrogen (H2).

Nitrous oxide (N2O).

Carbon monoxide (CO).

Ozone (O3).

Xenon (XE).

Radon (RN) in trace amounts.

Nitric oxide (NO) in trace amounts.

Nitrogen dioxide (NO2) in trace amounts.

The heaviest gas in the air is radon in the noble gas.

The material composition of the atmosphere.

The earth's atmosphere has constant gas components such as nitrogen, oxygen, argon, carbon dioxide, and nitrous oxide.

and other gas components with relatively fixed content, as well as water vapor, carbon monoxide, and sulfur dioxide.

and ozone and other gases that vary greatly.

The heaviest gas is radon in the noble gas, which is relative to atomic mass.

For 222, the lightest gas should be hydrogen in a noble gas with a relative atomic mass of 2

Air has weight. We can do an experiment where you weigh an inflated basketball and then inflate it and weigh it. You will find that an inflated basketball will be heavier than a non-inflated basketball. Explain that air has weight.

Air is everywhere around us, but how much does air really weigh? Do you know?

Yes! Everything in the world has weight.

There is weight, and the weight of a barrel of air is equal to the weight of a book or two pages.

The heavy ones are: O2, CO2, NO2, SO2, Cl2, HCL, O3, H2S and so on.

空 (air, kōngqì), which refers to the mixture of gases in the earth's atmosphere, belongs to the mixture. Layered on the earth's surface, transparent and colorless and odorless, it has an important impact on human survival and production.

It is mainly composed of nitrogen, oxygen, noble gases (helium, neon, argon, krypton, xenon, radon, gas O), 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 the latest data), and the volume fraction of other substances (such as water vapor, impurities, etc.) is about. The composition of the air is not fixed, and the composition of the air will change as the altitude and air pressure change.

But for a long time, it was believed that air was a single substance, until later 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 found through a large number of experiments that there were rare gases such as helium, argon, and xenon in the air.

Oxygen in the air is necessary for all aerobic organisms. All 1170s require oxygen to breathe, as does the respiration of green 1190. In addition, Green 1190 uses carbon dioxide from the air for photosynthesis, and air is almost the only carbon dioxide required by all 1190**.