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

• Why do you sometimes feel a shock if you walk across carpet on a winter day and then touch a metal door handle?
• What causes lightning?
• How does a battery enable a flashlight to light?
• Why do some appliances use three-prong plugs?
• How is information stored on a DVD?
• How do computers process data?

How Can You Reverse the Battery Direction in a Flashlight?

Procedure

1. Remove a battery from a two-battery flashlight. Notice that one end of the battery is labeled + (positive).
2. Return the battery to the flashlight in the same position it was in before. Turn the flashlight on and then off. Observe what happens.
3. Remove the battery and replace it so that it faces the opposite direction. Predict what will happen if you turn the flashlight on. Test your prediction.

Think About It

1. Comparing and Contrasting   Describe your results when the batteries faced the same direction and when they faced opposite directions. How are these results the same or different?
2. Inferring   What do your results indicate about how batteries might work?
3. Predicting   Do you think that the flashlight will work if you reverse the direction of both batteries? Explain your answer.