lesson on convection of heat, year 8

3. The purple colour from the dissolving potassium permanganate rises showing the flow of hot water in the convection current.

5. Ice and boiling water in the same boiling tube! Copper wire holds the ice at the bottom of the boiling tube, the top is heated. The heat from the boiling water at the top of the tube does not reach the ice at the bottom because a convection flow of heat cannot occur.

7. Showing convection in a gas. Smoke enters the metal box, it falls in the cool air and then rises once the air is heated by the candle flame.

8. Hot air balloons A hot air balloon works because the hot air inside the balloon has a lower density than the air surrounding it. We can make a simple one using a plastic bag. A real one can lift a lot of people in a basket.

14. Convection versus conduction In CONDUCTION the heat was passed on by VIBRATIONS in a SOLID In CONVECTION the heat is passed on by the FLUID expanding, rising and TAKING THE HEAT with it