Hot air is less dense than cold air, that is why it rises above cold air. You could also see it as cold air sinking and displacing the hot air below it.
Ye . that i know. But thats not the heat behaving . This is heated air opposed to cooled air. I want to know what happens at the smallest level of molecules when heat travels from one place to another. what partical is doing that. Does it have mass . Can it be slowed down or accelerated by gravity . Thats my area of darkness that i would like to see luminated so to speak