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The Water Cycle: A Demonstration

 The Water Cycle: A Demonstration


The Earth is a closed ecosystem. All the water we have is on the planet; as it goes through the water cycle, it is changed from one form to another. The three states of water are solid, liquid and vapor. Most of the precipitation in Colorado falls in the form of snow in the mountains. Coloradans rely heavily on the snow fall not only for recreation but also for water supply. We get 80% of our drinking water from snowpack.

The water cycle is a complex system. The major parts of the cycle include:

Evaporation: the sun evaporates water from ponds, lakes and the ocean and converts it to vapor or gas, which eventually cools and turns into clouds.

Precipitation: water that falls in the form of rain or snow from saturated clouds.

Infiltration: water that reaches the earth, either runs off the surface, falls into a waterbody, or infiltrates into the soil to collect underground.

Transpiration: underground water may be soaked up by plant roots and carried into their leaves. Water vapor is a by-product of plant transpiration, which uses solar energy, water and nutrients to create nutrients.

Respiration: when we breathe, small amounts of water vapor are released from our lungs.



This activity will introduce the concept of the water cycle by using a simple demonstration.

Materials Needed:

  • Clear plastic jar with lid (or smaller container that fits on top of jar)
  • Hot water
  • Bag of ice
  • Food coloring

How to:

Pour hot water into plastic jar, filling it about 1/3 of the way. Add several drops of food coloring to simulate dissolved material.Place inverted lid (or smaller plastic container) on jar and fill with ice. Observe and discuss what is going on.

Things to look for:

  • Steam rising from warm water (clouds)
  • Drops forming on bottom side of lid (rain)

Discussion questions

1. What happens to the water when it gets heated up?

2. What effect does the ice have on the water?

3. Discuss the water cycle as it occurs in nature.

4. How is this demonstration similar?/different?

5. What are the three states of water?

6. Where does most of the precipitation fall in Colorado? What form is it in?

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Last Page Update - Tuesday December 27, 2005