The bird is a simple heat engine. The tail is at room temperature and is the heat source while the wel head is cooling due to evaporation on its surface and is the heat sink. As the gas in the tail ...

Evaporation close evaporationThe process in which a liquid changes state and turns into a gas. is used to separate a soluble solid from a liquid. For example, copper sulfate is soluble in water ...

This process is called evaporation. The water vapour rises and collects in the sky as clouds. When the water vapour cools down, it condenses, turning back into liquid, and falls back to earth as ...