If hot air rises, why do you snow on a mountain top ?
Hot air rises, this is true...it's how birds are helped and gliders get about, due to thermal currents rising.
However, hot air rises because it has been heated by teh ground under it, not the Sun...(teh Sun heated teh ground)...so as it rises, it cools.
The air in teh upper atmosphere, is much much colder than the air at ground level, because it is so far from teh radiated heat from teh ground.
This is why, snow is able to survive on mountain tops, because the air around it, is very cold.
Why do dogs lick their balls?
Because they can!