why doesn 't carbon dioxide evaporate beyond the atmoshere?

Question

what does hold it near the earth's surface? i mean it should evaporate into space has gravity anything to do with it?

Answer 1

CO2 is a heavy molecule. It is dense than a number of other gases. Density = Mass per unit volume

Please refer to a graph that shows the distribution of molecular speeds and its dependence on molecular mass

As the graph shows, heavier molecules have lower mean speeds than lighter molecules. So, heavy molecules like CO2, travel at low speeds. They do not have enough speed to escape from the gravity of the Earth. Consider Hydrogen, it has a high speed and thus escapes from the Earth's gravity and that's a one reason for hydrogen being very rare on our planet.

Since CO2 has a higher density, it keeps closer to the Earth's surface.

Evaporation is the spontaneous vaporization of liquid. Since CO2 is a gas at atmospherical pressure and room temperature, the statement "it should evaporate into space" has obviously no meaning.

Answer 2

Gravity has *everything* to do with it.
That's what keeps the earth's atmosphere in place. Gases aren't as dense as solid matter, but they're still matter and are pulled by gravity just like any other matter. That's why the atmosphere is densest at the planet's surface, where gravity is the strongest.
Oh, and "evaporate" isn't the right term -- something that's already a gas can't "evaporate", as evaporation is the process of a substance changing forms from liquid to gaseous state through the addition of heat energy.

Answer 3

CO2, a gas does not evaporate, it already is a gas. Gravity holds it down as it does all gases in the atmosphere. It s heavier than O2 and N2.,

Answer 4

Gravity does. Holds it down to the surface.

Answer 5

Gravity, George W.

Answer 6

the last thing one would want is heavy carbon molecules up in the last layers of the earths atmosphere, life depends on the carbon cycle to survive, it is the only thing that transports a heavy amount of oxygen in to the sea, without it you wouldn't have fish. or you for that matter. it is streamed in these cycles like everything else because of the energy of the sun... therfore gravity is partly to blame as it is one of the cycles.

Answer 7

co2 o2 and N2 are very heavy gases. Gravity holds it.

Answer 8

gravity pulls it down

Answer 9

there is some leakage.
gravity holds it to earth

see here
http://en.wikipedia.org/wiki/Atmosphere