1. Topic-
Models of the Water Cycle
2. Content-
Water cycle
3. Goals: Aims/Outcomes-
1.to develop understanding of the water cycle.
2.to understand that water will soon be categorized as a nonrenewable resource.
Materials and Aids-
1.Models of the Water Cycle student E-Sheet
2.Half gallon jars
4.Masking tape
5.Food coloring
6.Large Ziploc® plastic bags
7.Thermometers with a large range

A. Introduction-

1.What images represent "cycle"?
2.What shapes best represent cycles?
3. Have you ever heard of the water cycle? What do you know about it?

B. Development-

After a review of the water cycle, have students use their student E-Sheet to go to and critique the illustration at Thirstin's Water Cycle Adventure.
Ask students these questions:
Does the illustration do a good job of showing the water cycle?
Can you think of ways that it can be improved?

Tell students that they will build two models of the water cycle and decide which model is best. Instructions can be found on the student E-Sheet.
Model 1:
Working in groups, have students build the water cycle model described in the side bar on the Water Cycle page of the Oceans Alive website. Each group will need two half gallon jars, a rock, masking tape, and food coloring. Have the groups watch and record what happens to their model as it warms on a sunny windowsill in their science journals. In their own words, they should describe how the model explains what happens in the water cycle.
Model 2:
Have the student groups build the model on Going Further: Building a Model of the Water Cycle. Each group will need a large Ziploc® plastic baggie, food coloring, masking tape, and a thermometer with a large range. In addition to building the model, they should reflect upon and explain what their models show. They should answer all the questions in the activity in their science journals. In their own words, they should describe how the model explains what happens in the water cycle.


Have students reflect on the differences in the models. They should list the advantages and disadvantages of each.
Ask students:
How accurately do the models represent the process of the water cycle?
How are the models alike? How are they different?
Was one more simple than the other?
Which one does a better job of explaining the water cycle? Why?
Which did you find most useful in helping you understand the water cycle?
Is there an aspect of the water cycle that is not well represented by either model? If so, how could you change the model to make it better?
To assess student understanding of the water cycle, have students revisit the illustration on Thirstin's Water Cycle Adventure. Have students revise their critique of the illustration based on what they learned about the water cycle from studying and comparing the two models that they built.
To assess understanding of the usefulness of models, ask students to rank the following according to how well they represent the idea that the earth's water is constantly recycled: the water cycle illustration; model #1; and model #2. Students should support their rankings by listing reasons for their choices.

This Lesson Plan is available at (www.teacherjet.com)