atmosphere remains intact withthe earths surface.why?

Question

according to kinetic theory gas molecules are not influenced by the force of gravity.then how is it that atmospere a gaseous envelop is not lost and remains intact.

Answer 1

Actually...

gas molecules ARE influenced by gravity (they have mass, therefore they're influenced). The reason kinetic theory models them without gravity is that they generally have enough kinetic energy that there motion can be modeled without gravity to a certain amount of accuracy. But kinetic theory can take into account gravitational effects - it just makes the equations a bit harder to deal with.

So, to answer your question, gravity IS why the gas molecules stay around the Earth.

I also want to point out that the atmosphere (or large gas cloud and stars in space) is not usually modeled with the kinetic theory, but with fluid mechanics (which ignores the molecules and treats the fluid (gas/liquid) in bulk. This is done because those equations are easier (Not EASY, but easier on the large scale) to deal with.

EDIT: The rotation of the earth actually exerts a small (compared to gravity) outward 'force' on the molecules (countered by gravity) and the revolution would only exert an inward force in the direction of motion, and the gas would flow around the planet (like air across an airplane wing) if it wasn't for gravity.

The density differences in the atmosphere causes a layering effect (most dense sinks while least dense rises). Without gravity, the density wouldn't make any difference. Further more, the density differences are CAUSED by gravity since you can treat the atmosphere, for the most part, as a uniform gas mixture (i.e., the density would be constant if no gravity was present). This is the same reason as the pressure of water increases the deeper into a pool (or more dramatically the ocean) one goes.

So gravity plays a role in all of these things.

Answer 2

Your assumption about gravity is wrong. The force of gravity exists between any objects that have mass and gas molecules are no exception. The atmosphere remains effectively orbiting the earth purely though the force of gravity.

Answer 3

1. Gravity
2. Temperature: if it is too high the molecules thermal motion can exceed the planet's escape velocity.
3. molecular weight: lesser molecules are lost more rapidly into space.
4. UV photodissociation of water for example: H2 is lost. The ozone layer would reduce the amount of H2 lost.
5. Magnetic Field protects the atmosphere from the solar wind.
6. Giant impact erosion.
7. Weathering: CaSiO3 + CO2------ CaCO3 + SiO2
8. Outgassing of H2/He from volcanic eruptions

All this processes affect our atmospheric composition.

Answer 4

Hi. ALL molecules are influenced by gravity. Gravity holds the atmosphere to Earth.

Answer 5

Gravity & Density... as well as the rotation & revolution of earth are the key factors of atmosphere being intact with the earth....

Also earth has wonderful cycles (for most gases) like oxygen, nitrogen etc.. so that the consumed or lost part of air can be replenished.....

Answer 6

Wrong basis. Gas molecules are influenced by the force of gravity.

Answer 7

the actual question is why can we fall, in view that issues do not bypass except they have something to push or pull them. What pulls us, the earth, and each thing else are magnetic fields that are more suitable the bigger an merchandise is and the shorter the gap like an familiar magnet. we are pulled to the earth because the earth is gigantic, and the earth is pulled with the help of the solar by using the undeniable fact that's a lot higher besides the undeniable fact that it is also pulled, yet a lot less, to the moon too, and each thing else relative to the gap and length, to orbit around the solar.

Answer 8

If it has mass it is influenced by gravity.

Answer 9

By the grace of God.