Question

a closed container has air at 20 degree Celsius. some air at 50 degree celsius is inserted into the centre of the container. in which direction will this air move- upward, downwards or not at all?

Answer 1

It will move upwards. Cool air is dense and tends to fall in the presence of warmer air, while warmer air is less dense, and it is displaced up by the cooler air. 

Answer 2

the centre of the container temperature is 30 or 40 degree celsius the air move upward at all