Day 32 What is condensation? The process of water vapor changing to liquid water. What is humidity? the amount of water vapor in the air What is mass? the amount of matter in an object or sample What is density? the amount of matter in a given amount of space; heaviness-for-size Do water molecules gain or lose energy when they condense? They lose energy. Water vapor molecules must slow down in order to become liquid water molecules. 1

Clouds & Precipitation, cont. Investigation 6, Part 4b Water in the Air

Discuss Clouds Discuss the following questions with your partner: Where do clouds come from? How do you think they form? Daily Warm-Up Exercises 3

Cloud Bottle This bottle contains about 25 ml of water. How can we make a cloud appear in this bottle? How can we get water vapor into the air inside the bottle? shake the bottle Let's try it. Daily Warm-Up Exercises 4

Add Pressure We need to increase the energy inside the bottle. If we increase the pressure, the molecules will collide more and the temperature will increase. Warm air will hold more water vapor. Daily Warm-Up Exercises 5

Release Pressure What will happen when we release the pressure? the temperature will decrease What might happen when the temperature decreases? the water vapor might condense and form a cloud Let's try it. Daily Warm-Up Exercises 6

Secret Ingredient There is another ingredient in the cloud recipe. Water vapor in the air needs a surface to condense on. We'll add some smoke, which is made up of tiny solid particles suspended in the air. This will give the vapor molecules a lot of tiny surfaces to condense on. Let's try it. Daily Warm-Up Exercises 7

Condensation Nucleus The particle on which vapor condenses in the air is called a condensation nucleus. What materials might provide condensation nuclei in the outside air? dust, smog, air pollution, smoke, salt, chemicals Daily Warm-Up Exercises 8

Precipitation What is precipitation? water that falls from the sky Is dew a form of precipitation? no, it doesn't fall from the sky Turn to page 80 in the Resources book. This shows how raindrops and cloud droplets compare in size. Daily Warm-Up Exercises 9

Visualization Exercise 6.2 Labels >>>next slide<<< Visualization Exercise 6.2

Resources, P. 38 Exercise 6.2 Image comprehension focus: Labels and Connection to text Rationale: This image uses a variety of labels to explain cloud layers. Integrating multiple labels will allow students to apply what they have already learned about labeling in diagrams, and give them an opportunity to extend that learning. Type of Activity: Teacher guided discussion Objective: To reinforce student understanding of the diagramming conventions labels and connection to text. Module Images: Resources, P. 38 Procedure: Note: As with the previous exercise, the small size of the type may make the projected image difficult to read from a distance. Instruct students to open their books to page 38 and read the labels on the original image. The projected image will still be useful as a way of showing students what parts of the diagrams to pay attention to as you work through the exercise. Explain: “This diagram has a large number of labels, and in order to sort out the information we need to figure out how those labels are organized. It may not be obvious, but there are really three groups of labels here. Ask: “For example, there is a label which reads ‘Low-Level Clouds.’ There are two other labels that belong to the same group. Which ones are they? [Let the students figure this out. If necessary guide them to see that the other two are ‘Middle-Level Clouds,’ and ‘High-Level Clouds.’] Ask: “How can we tell that these three go together?” [There are several possible answers to this question. Students may notice that the three labels use parallel wording. Students may also notice that these three labels are consistently located immediately below a boundary line – either a dotted line or the top of the picture. Finally, students may notice that these labels are written in all capital letters, making them visually different from the other labels. Before moving on, make sure that all three of these features are discussed – pointing them out if the students do not notice them on their own.] Ask: “What are the other two groups of labels? [It does not matter which order these are discussed, but make sure that both are covered. One group consists of naming labels for specific kinds of clouds – stratus, altocumulus, cumulonimbus and cirrocumulus. The other group are altitude markers, which show how high off the ground one typically finds each kind of cloud – 2000m, 4000m, 6000m, 8000m.] Ask: “What is an example of a middle-level cloud? [altocumulus] Ask: “How high off the ground would we expect to find an altocumulus cloud? [between 2000 and 5000 (roughly) meters.] Continue to ask the same questions about other specific clouds until your students are able to answer reliably. >>>end of exercise<<<

Reading Read Observing Clouds on pages 37-41 of the Resources book. Answer the questions on page 42. Daily Warm-Up Exercises 12