Chip Off the Old Rock

Here’s a lab oriented lesson from the Cispus Learning Center about erosion and weathering that can be done at in the classroom or at any outdoor school…“A Chip Off the Old Rock”

Focus: To explore the affects of weathering on rock using observation, prediction, measurement and experimentation skills.

Group Size: Entire class, divided into small groups.

Time Required 30 minutes

Materials:

• Glue or a hot glue gun
• Pie pans
• Box of sugar
• Balance
• Water-misting bottles
• White drawing paper

Physical Setting Process: Cispus Classroom

1. Assign students to work in groups of two or three. Tell half the groups that they will be Tumblers and the other groups that they will be Misters. Give each small group ten sugar cubes. Put some cubes aside for comparison at the end of the investigation.

2. Each group should create a rock formation out of the sugar. Have each student glue their rock formations into a solid form using glue or the hot glue gun. Caution students that a little glue goes a long way. Let them dry overnight. If you've used regular glue, the formations may take longer to dry.

3. Have each group draw a picture of their rock formation. Weigh it, and record the weight.

4. Explain that the Misters will place their rock formations in a pie pan in preparation for spraying them with water. Then the Tumblers will place their rock formations in empty yogurt or margarine containers and seal them.

5. Have each group form a hypothesis about what they think will happen to their rock formations (i.e. "If we shake our rock formation for two minutes, it will change shape.").

6. When you give the signal to begin, the Misters will spray their rock formations with water and shake them around in the pie pan for two minutes. The Tumblers will shake their sealed containers vigorously for two minutes.

7. After the experiment, have each group weigh their rock formations again. Have the Misters and the Tumblers display their rock formations alongside the rock (sugar cubes) that you have set aside. What rock comparisons can they make between the rocks? How do the results compare with the hypothesis? How can you compare these results to the effects of weathering on rocks?