science experiment - convection in gases

Convection is the transfer of heat by the movement of a fluid (liquid or gas) between areas of different temperature.

Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy. Heat energy is transferred from hot places to cooler places by convection. Liquids and gases expand when they are heated. ... The denser cold liquid or gas falls into the warm areas.