What are the three ways that air rises?

ok I guess hot water is lighter than cold water but what about hot air and cold air? we can breathe cold air but not hot air ...

What are the three largest cells in the world and what are the three smallest?

This is really random but can water dissolve substances in all three states? It's a yes or no wuestion only...Thanks =)

I kn that ammonia gas is less dense than air, but is there any rule to kn whether a kind of gas is less dense than air, says,...

If heat rises why is there always snow on the top of mountins and it gets colder the higher you go?

What is air's weight?

RT, a bag of white powder suspected hypoxanthine, several simple identification method!

I have 3 carnations that I really want to keep. I have pressed flowers before. I was looking for other ideas, I have sprayed ...

I need an answer based on Plate Tectonics. This is about the Earth sliding apart &pressing together.

..just simple items that won't cost money??? Sorry, but i'm kind of desperate at this point, and we have no clay that i can u...