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

• How can balloons have many different shapes?
• Why should you check the air pressure of tires before you go for a long drive?
• What controls the movement of air into and out of your lungs as you breathe?
• Why does pasta take longer to cook in Denver than in New Orleans?
• How is the altitude of a hot-air balloon controlled?

How Easy Is It to Compress Air and Water?

Procedure

1. Insert a plunger into a syringe that is sealed at the narrow end. Push the plunger into the syringe as far as you can. Use the marks on the side of the syringe to read the volume of the air inside the syringe. Record this volume.
2. Remove the plunger. Fill the syringe with water by holding it under water in a large plastic container of water. CAUTION: Wipe up any spilled water right away to avoid slips and falls.
3. While holding the syringe over the container, repeat Step 1. Record the volume of the water.

Think About It

1. Comparing and Contrasting   Which was harder to compress, the air or the water? (To compress means to squeeze into a smaller volume.)
2. Inferring   Based on your answer to Question 1, in which material are the particles closer together, in air or in water? Explain your answer.