NORTHWEST WEATHER WATCH
Experiment #5: Rainmaker
You can fill out this Lab Sheet
on the computer and send it to your teacher's email address by clicking
on the submit button when you are finished. Or click on this version,
print it out, and fill it in by hand.
Question: What causes precipitation?
Discuss in your group what might cause the condensed water
(cloud) to turn into precipitation (rain). On your Lab Sheet record your
In this activity you will be using the materials below to simulate one
phase of Earth's water cycle - precipitation.
We have already seen how water vapor (evaporated water
in the air) condenses onto tiny particles when the air is
cooled and forms a cloud. Your task will be to conduct a
"precipitation simulation" and to formulate a hypothesis
explaining how the condensed water (cloud) turned into
You will need for each group:
The Experiment (Simulation) Procedure
- a pan of water
- a burner
- a large cookie sheet
- ice cubes
- 2 metal trash cans
Compare your simulation to Earth's water cycle. Which
stage of the simulation represented....
- Place a pan of water onto the burner.
- Place 2 metal trash cans on either side of the
- Place the cookie sheet on the 2 trash cans so
that it forms a "ceiling" over the pan of water.
- Place the ice cubes on top of the cookie sheet.
- Heat the water and watch as the steam
accumulates and hits the cool surface.
- Record your observations on the Lab Sheet.
Discuss in your group what happened to cause the
condensation to turn into precipitation. Have you changed
your hypothesis? Why or why not? Go to Hypothesis
Revisited on your Lab Sheet and record your response.
After your group has shared its findings with the class,
decide upon your concluding hypothesis and record it
on the Lab Sheet.