Why Does Gas Float Upward: Investigating Mass Difference

[AstrophysicsX]

Why does gas float upwards instead of falling towards the Earth ? Is it a mass difference ?

 

[Andrew Mason]

Why does gas float upwards instead of falling towards the Earth ? Is it a mass difference ?

What kind of gas are you talking about?

If you have a balloon filled with the a gas that is lighter than air (eg. He - an atom of He is lighter than a molecule of N₂/O₂) the balloon will rise. But if it is filled with a gas that is heavier than air (eg. CO₂), it sinks.

AM

 

[AstrophysicsX]

Why does it being lighter than air have anything to do with it floating upwards. Isn't mass supposed to be attracted to the Earth, therefore falling?

 

[SteamKing]

When you drop a stone into a lake, it sinks. When you put a boat into a lake, it doesn't sink. Don't the stone and the boat both have mass? Why does one sink and the other float?

 

[pallidin]

Another way to look at this might be:
Would a helium balloon rise or fall on the moon? Answer: It would fall.

 

[AstrophysicsX]

But why ? Explain please.

 

[cdotter]

But why ? Explain please.

Things float because of differences in buoyancy. There is no air or any other gas on the moon (I think) so there's nothing for a helium filled balloon to float on or sink in. The force of gravity would slowly pull it down.

 

[russ_watters]

But why ? Explain please.

People are trying to help you by making you think, rather than spoon feeding. Do you not know why boats don't sink? Can't you apply that to a balloon? Even if you aren't sure, answer questions with a guess. Exercising your brain makes it work better.

 

[JaredJames]

Yea. comparatively gas has low wait. that's why its floats.

Yeah, gas doesn't stick around too long...