English: Demonstration of the Leidenfrost effect. At the instant a heated metal ball is placed in warm (≈ 60°C) water, a layer of water vapour forms around the ball. The vapor acts as an isolator and does not allow direct contact between the heated metal ball and the significantly cooler water. At the beginning, the metal rod cools faster (its volume is smaller), making the nearby water to boil first. After a while, as the ball cools down, the layer of water vapour disappears and the water comes into contact with the heated ball. The water starts boiling intensively and drops are splashed out of the beaker. At the end, the water and the ball reach thermal equilibrium.
Planned and performed by Marina Stojanovska, Miha Bukleski and Vladimir Petruševski, Department of Chemistry, FNSM, Ss. Cyril and Methodius University, Skopje, Macedonia.