Heat transfer
Heat convection
In heat convection the energy transport happens because of the movement of the particles that carry heat energy.
The hot air above a candle ascents because of its lesser density compared to the air of the environment and moves the small paddle. (Click on the triangle to start the video.)
The natural convection can be visualized with a bottle of hot coloured water. When the bottle is put into a container with cold water the coloured water rises because of its smaller density, just like warm air. (Click on the triangle to start the video.)
