Question

why always smoke rises up?​

Answer 1

Answer:

It's density is less than air

Explanation:

when something heats up its volume increases and the density decreases

so they rise up

Answer 2

Answer:

Smoke is hot air. Thus, it's density is lower. High temp. = low density. And objects with low density always rise up.

Explanation:

Smoke is hot air. So it rises up too.