Responding to Patterns of Change

Allow students time to answer these questions. Once they have had time to complete their responses, you may want to hold a class discussion on some or all of them.

1. Think about the investigation in which you added ice cubes to a can of water.

   1. How would you explain what happened to the outside of the can?

   Students probably will have noticed the film of water on the outside of the can. They might think that the water leaked out of the can. If you hold a class discussion about their responses, see how many different ways they can think of to develop a thin layer of moisture on the outside of the can. This question may provide insight into their prior knowledge.

   Because this is an Engage activity, it is intended to provide students with a hands-on experience to stimulate their thinking. As they move forward in the chapter, they will be introduced to the term for the phenomenon they are observing now—condensation. During the Explain phase of the chapter, the term condensation and the explanation for how condensation occurs is introduced. For now, focus on having students express their current ideas.

   2. How might you test the explanation you provided in Question 1a?

   Students could test the “leak” theory by sealing the entire can with plastic wrap or foil and conducting the experiment again. Or they could observe another can still holding water at room temperature. Does that can develop a layer of moisture? Another option is to observe another can that is cold (stored in a freezer or a cooler) but starts out dry and empty. If a thin layer of moisture forms on the can, then the moisture could not have leaked from inside the empty can.

2. What similarities did you see between what happened with the can of iced water and what happened in the demonstration?

Students will probably notice water droplets on the can and on the walls of the covered glass container. As a follow-up to Question 1 about the moisture on the cans, you might want to ask students where the water droplets in the covered glass container came from. (Although students will be introduced to the terminology and explanation later in the chapter, note that the moisture in each case is a result of the condensation of water [H₂O] vapor onto a solid as liquid water.)

3. Look at the photograph in figure 1-3. What is happening to the water? How does it compare with the investigation you did in this Engage activity?

The air this horse is breathing out contains water vapor. When the vapor makes contact with the cold air, it turns into small droplets of liquid water that we can see as “breath fog.”

4. Can you think of any similarities between the activities you did in this lesson and weather events you may have observed in nature? If so, record your answers in your technology notebook.

   The intent of this question is to gauge students’ prior knowledge about the movements of water in the atmosphere—especially with respect to weather. Students are likely to respond that rain and snow involve the movements of water, but they may not be thinking about changes in state (liquid to vapor or vapor to liquid). Because this is an Engage activity, encourage students to express their current thinking. As they continue in this chapter, they will build on their understanding and learn more about the physical processes that occur with respect to the movements of water in the atmosphere and how those water movements affect the weather.

5. In this activity, you shared responsibility for the investigation with your teammates. How did this affect your work?

This question helps students think about the importance of teamwork. Students will likely realize that the investigation would have been more difficult for one person to do alone. They might also realize that having a team helped them make more thorough observations or think of new ways to explain the results.