Question

4. Warm air is________ lighter than cold air​

Answer 1

Warm air is very lighter than cold air

Answer 2

Hot air is lighter than cold air. The reason fr this is when air gets heated up it expands and becomes less dense than the air surrounding it also the distance between the molecules increases. So the less dense air floats in the much denser air just like ice floats on water as ice is less dense than water.