Question

hot air takes place of cold air due to convection why?

Answer 1

Because Hot air is lesser in density than cold air so it floats upwards and slightly occupies the space/volume of cold air which is more denser in density

↪This happens due to convention netween the molecules of the gas

Answer 2

As the hot air rises, the cool air rushes in to take its place. As that cool air that rushed in heats up it rises, and again outside cooler air rushes in to take its place. This is the basic mechanism of a convection cell. ... This makes the hot air less dense than the surrounding, cooler air.