When a liquid drop is placed on a surface that is held at a temperature much higher than the liquid's boiling point (such as a drop of water in a very hot pan) it hovers on its own vapour cushion, without wetting the surface (figure a below).This phenomenon is called the Leidenfrost effect (or film boiling) and occurs beyond a surface temperature called the Leidenfrost point (about 200 - 300 C for water on flat surfaces, depending on surface quality).

Link: Droplet Movies
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