1. The Water Cycle

2. Facts About Water Water is the most important material on earth. Water continuously changes forms so it can be used and recycled. Matter on earth, including water, is never created or destroyed. Approximately 70% of the planet is covered in water.

3. Forms of Water Water can be found in three forms – Liquid Example: oceans, lakes, rivers, streams, groundwater – Gas Example: water vapor – Solid Example: ice, snow

4. The Water Cycle Precipitation Runoff Evaporation Condensation

5. Precipitation Precipitation occurs when droplets in clouds join together and become large enough. Precipitation can fall in the form of rain, snow, sleet, or hail, depending on the temperature of the air through which the droplets fall.

6. Runoff After precipitation occurs water moves through the environment back towards larger bodies of water. http://www.desktopscenes.com/Scenes%20from%20Glacier%20National%20Park%20(2004)/Runoff%20 Waterfall%20Near%20Logan%20Pass.jpg

7. Evaporation Evaporation happens at all times. The rate of evaporation increases when temperatures are higher and air surrounding a water source is drier. Living things also contribute through perspiration, which is the release of water vapor through the skin. We can also exhale water vapor in our breath.

8. Condensation The air can hold only a limited amount of water vapor. The amount of water vapor the air can hold depends on the temperature of the air. – Warm air can hold more water vapor than cold air. When air reaches a temperature where it can hold no more water vapor it is said to be saturated. This is called the dew point. When the temperature falls below the dew point the water vapor begins to condense, or come together. High above the ground clouds form. Near the ground fog forms. On solid ground dew or frost forms depending on the temperature.

9. Condensation When most air cools, water vapor condenses and clings to tiny particles of dust, smoke and salt, forming clouds. When the droplets in clouds join together and become large enough, they fall to the ground as precipitation.

10. Pictures All pictures are from Microsoft Clipart.