Return to Book List Grade 2   Watering Earth's Plants   Water on the Move     When water evaporates, it changes from a liquid to a gas in the air that you cannot see.   When water condenses, it changes from a gas back to a liquid that you can see.   The moving of water between Earth and the sky, over and over again, is called the water cycle.   In the water cycle, liquid water from land, oceans, and rivers evaporates into the air.   The water in the air condenses and makes clouds in the sky.   The water drops in the clouds get bigger and fall to Earth as rain, snow, or hail.