Water can exist in three states of matter--liquid, solid, and gas--and you have probably seen all three states of water around your house! Usually when we think of water, we picture the liquid form that comes out of our faucets, but of course, ice cubes and steam are water, too!
Water in the natural environment changes between these three states in what’s called the water cycle. The water cycle is the circular pattern where water changes from gas to liquid or solid and back to gas in a continuous loop. In this loop, water collected in bodies of water like oceans, lakes, and rivers is turned to water vapor by sunlight in a process called evaporation. From there the water vapor rises to become part of the atmosphere. When water vapor in the atmosphere cools, it is turned back into a liquid, which you can see as clouds. This process is called condensation. From the clouds, water falls back to earth in liquid or solid form, called precipitation, which you see as rain, snow, hail, or sleet. Liquid water then flows back into bodies of water through runoff. Runoff occurs when water flows across the earth’s surface due to gravity, much like when your family washes the car, and the excess water flows down the driveway, into the gutter, and into the drain. Once water falls back to earth, it continues again into the water cycle through the stages of evaporation, condensation, precipitation, and collection.
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