How do science concepts apply to your world? Here are some questions you'll be able to answer after you read this chapter.

• Where is most of Earth's fresh water found?
• What are hoodoos, and how are they formed?
• How is a river like a dump truck?
• When was the Chicago region covered by a sheet of ice more than a kilometer thick?
• How would Earth's surface look if the oceans were drained?
• How can scientists determine the age of a fossil or a rock?
• How do scientists explore the ocean floor?

How Do Freezing and Thawing Affect Rocks?

Procedure

1. Your group will receive 5 similar rocks to examine for signs of damage. First, look closely at rock A, which was not treated. It is the control. Record your observations.
2. Examine rocks B through E. (Rock B was soaked, frozen, and thawed once; rock C was soaked, frozen, and thawed twice; rock D was soaked, frozen, and thawed three times; and rock E was soaked, frozen, and thawed four times.) Record your observations.

Think About It

1. Observing   What effect did one freezing and thawing cycle have on rock B? How did repeated freezing and thawing cycles affect rocks C through E?
2. Inferring   What property of water do you think causes the changes you observed?
3. Predicting   How would frequent freezing and thawing be likely to affect rocks exposed on the tops of mountains?