1. What is the water cycle?

2. Key Terms Water cycle Evaporation Condensation Precipitation
Transpiration
Infiltration
Runoff

3. The Water Cycle Water is always changing state.
As water evaporates from the surface, it changes from a liquid to a gas.
In the atmosphere, the water vapor condenses to a liquid and forms clouds.
Finally, the water falls back to Earth as precipitation.
This repeated movement of water between the earth and the atmosphere is called the water cycle.

4. The Water Cycle Illustrated

5. Evaporation Evaporation is the process when liquids change to gases.
Most of Earth’s surface is covered with water.
When liquid water absorbs enough heat energy from the Sun, it changes into water vapor.

6. Condensation The changing of a gas to a liquid is called condensation.
When air containing water vapor is cooled, the water vapor loses heat and changes to a liquid.
Water vapor condenses into tiny droplets of water.
These droplets join together to form clouds.
If the temperature is freezing, ice forms.
A cloud is a collection of water droplets or ice crystals.

7. Condensation

8. Precipitation
Water that falls to Earth from the atmosphere is called precipitation.
Rain and snow are the two main forms of precipitation.
As the water droplets in the clouds grow bigger, they become too heavy to stay in the air and gravity pulls them toward the Earth.

9. Precipitation

10. Transpiration
Transpiration is the process of water loss from plants

11. Soaking it Up = Infiltration
Infiltration happens when water soaks into the soil from the ground level. It moves underground and moves between the soil and rocks.

12. Runoff
Runoff is the movement of land water to the oceans, chiefly in the form of rivers, lakes, and streams. Runoff consists of precipitation that neither evaporates nor penetrates the surface to become groundwater.

13. Checking Concepts
The process by which a gas changes to a liquid is called __________.
The main forms of precipitation are __________, and _________.
The ______________ is the repeated movement of water between Earth and the atmosphere.

14. Answers
Condensation
Rain and snow
Water cycle

15. The End