Simulating Plasticity Name ____________________________________

Problem:

How can the plasticity of the earth’s mantle be simulated?

Materials:

Cornstarch water 2 small beakers Stirring Rod Dropper

Procedure :

1. Put 15 g of cornstarch in one of the beakers. In the other beaker pour 10 mL of water.

2. Using the medicine dropper, gradually add one dropper full of water to the cornstarch. Stir the mixture.

3. Continue adding water, one dropper full at a time until. Stir the mixture after each addition. When the mixture becomes difficult to stir, stop adding water.

4. Try to pour the mixture into your hand. Try to roll the mixture into a ball and press it.

5. Place your mixture in the large beaker. Clean up your lab area.

Observations:

1. Before the addition of the water was the cornstarch solid, liquid, or gas?

2. What was the phase of the water?

3. When you try to pour the mixture into your hand, does the mixture have the properties of a solid, liquid, or gas?

4. When you try to roll the mixture into a ball and apply pressure, does the mixture act like a solid, liquid, or gas?

Conclusions:

1. How is the mixture of cornstarch and water like the earth’s mantle?

2. How is the mixture different from earth’s mantle?

3. How might the plasticity of the mantle influence the movement of the earth’s lithospheric plates?