What is the water cycle?
Did you know that the water you drink is millions of years old? It’s the same water that dinosaurs used to drink, that old kings and queens used to drink, and it’s also the same water that we flush down the toilet!
This is because the water on Earth is always the same, going in cycles around and around, changing into ice, snow, or water vapour. This is called the water cycle.
Heat from the Sun makes water from the oceans and lakes turn into gas, this is called evaporation. The heat from the Sun also turns water on leaves into gas, this is called transpiration. All this gas flies up into the sky and cools down, becoming liquid again, this is called condensation.
The liquid in the sky forms clouds and when the clouds are heavy the water falls from the sky. It can fall either as rain, snow, sleet, or hail. This is called precipitation. Now that the water is back on the ground, the Sun heats it up and the cycle starts all over again.
Heating and cooling
Liquids and gases can change from one state to another by heating or cooling. Heating can turn liquids into gas. This change of state is called evaporation.
Cooling can turn gas back into liquids, this is called condensation.
