Apparatus: Bars of stainless steel, aluminium and copper, a candle, a burner, pins, etc. :
Procedure: Take stainless steel (or iron), copper and aluminium bars, each about 30 cm long and having the same shape. Apply wax spots with the help of candle at a distance of 2 cm from each other on all the three bars. Stick a pin in each of these spots so that it is upright. Now insert the ends of all three bars into a flame at the same time. for a while. What do you see? From which bar do the pins start falling first? Why?