Rain and the Water Cycle

General Objective- Describe how water exists on earth in three states

Lesson Objective-What makes the rain?

Motivator-Ask the questions:
  What do you know about rain?
  How does it get to Earth?
  What forms cloud?
  *Have students take turns answering each of the questions and try to explain rain.

Materials-
  kettle (ideally electric, otherwise you’ll need a stove)
  small saucepan
  shallow pan
  water
  icecubes
  “What Makes Rain” activity sheet
  small jars with tin lids
  overheads of the water cycle
  flashlight
  50 minutes
 
Demonstration-
 *Activity must be done with adult supervision.

1. Heat some water in a kettle.
2. Place some cold water and ice cubes into a small saucepan.
3. After the water in the kettle starts to boil, hold the small saucepan full of cold ice water just above the steam.  put a shallow pan beneath the saucepan to catch the water.  Watch water droplets form on the bottom of the saucepan.  When the water droplets become large enough to drop off it starts to “rain”.
4. Show overhead of water cycle and discuss how this demonstration is like the water cycle.  What does the kettle of boiling water represent?  Where are the clouds in the model?  What causes it to “rain”?
 

Activity- Start with this question: Do you think that we can make rain just using this jar?

1. Have students get into groups of two and pass out a jar with a metal lid to all groups.
2. Pour about five centimeters of very warm water into the jars.
3. Place the lids of the jars upside down over the mouth of the jars.  Allow it to sit for a few minutes.
4. Place ice cubes in the lid.
5. Darken the room and shine a light through the jar.
6. Pass out the worksheet and have them follow the directions on it.
7. Discuss as a class what is happening and why.

Teaching Strategies-Discussion, Demonstration, Observation, Investigation, Guided Discovery

Vocabulary-

Accumulation-water that collects on the earth’s surface.

Condensation-the process in which invisible water changes into liquid water

Evaporation-liquid water droplets being changed into invisible water.

Precipitation-water that falls as rain or snow.

Water-the liquid that comes from clouds as rain and forms streams, lakes, seas, and oceans.

Water cycle-when water leaves the Earth’s surface through evaporation.

Water Droplets-water that can be seen.

Water vapor-water that cannot be seen.

Assessment-Class discussion and worksheets.  Individual
 

Teaching and Learning Processes-Observing, classifying, predicting, collecting and recording data, applying, communicating.
 

Extensions-

1. Do the activity Drying on the Line (AIMS, Volume 9, Number 7).
2. Activities that show there is water in the air at all times using frost.  You can do this by filling a clean metal can with ice, then add rock salt.  Discuss what happens.

Resources-

     Bosak, S.  Science is…  Scholastic Canada Ltd.  1991
 
     Hoover, E; Mercier, S.  Primarily Earth AIMS Activities.  AIMS Education Foundation.  1996