Step 1: Each pair of students will have 1 soda bottle and cap, 1 thermometer, and a strip of masking tape. Have students use a small piece of tape to secure the thermometer so that it is attached to the inside of the cap. Carefully lower the thermometer into the bottle and screw the cap on tightly. Handle the bottle by the cap only. You do not want to allow any heat transfer from the students' hands through the plastic bottle. Now they have created a closed system of air.
Have students look at the temperature of the air inside the bottle and record their data. Ask the class to make a list of the measurable characteristics of this system. Discuss their lists and make sure that the characteristics of volume (2 liters), temperature (check the thermometer), and pressure (to be discussed) are included in their lists.
Step 2: Now, ask how they might change any one of the three principle characteristics without opening the bottle or putting anything else into or out of the bottle. Discussion should lead to compressing the bottle. Have one student take a bottle which has been filled with water and left uncapped between his hands. Be sure to do this over a sink or large pail. Ask the students how much water is in the bottle when it is full and unsqueezed. Now have the student slowly and carefully squeeze the bottle until the sides are almost touching. What happened? Is the bottle still filled to the top? Is the volume of water still the same? How do you know is? Discuss the students' responses.
Step 3: Finally, ask students what will happen when they squeeze their closed bottles. Will the amount of air in the bottle change? What will change? Ask them to write their prediction on a sheet of paper. Let each group squeeze the bottles, noting the volume change and temperature change. Ask them what they think has happened to the pressure inside the bottle as they squeeze it. (Pressure increases with decrease in volume in a closed system. Temperature will increase under the same conditions.) Allow the bottles to pop back to shape and "cool" down again. Repeat the activity to validate their findings. They should now be ready to discuss the relationship of volume, pressure, and temperature.
Provide your students with a FOCUS FOR MEDIA INTERACTION, by asking them to name the location and conditions at the point in the atmosphere where most of the water is located. Start the video at the picture at the visual of the earth as seen from space. The words, "The Atmosphere" are superimposed over the visual. The narrator has just stated," I think there's more to the atmosphere than you may have guessed." Pause the video at the visual of the forest and the narration cue," Life on the planet couldn't exist without the troposphere, since it holds the atmosphere's water and oxygen." Discuss why the students think all the water is in this layer.
Provide your students with a FOCUS FOR MEDIA INTERACTION, asking your students to write down a theory as to how they think the water makes its way into the atmosphere in this layer. Students should check their theories against the information presented in the next video clip. Start the video and run through the visual of the picture of the waterfall and the narration, " .... critical to life on earth." Pause to ask students if they were correct in their predictions.
Provide your students with a FOCUS FOR MEDIA INTERACTION, by asking your students to list the processes illustrated in the water cycle video clip they are about to watch. Start the video and run it through the picture of the ocean and the appearance of the globe spinning on it. The audio will be," .... over and over again." Stop the video and discuss the processes involved in the water cycle.
INSERT Science for You, #8 into your VCR. Provide your students with a FOCUS FOR MEDIA INTERACTION, by asking students to determine if there is water in the air in the classroom. How did it get there? Start the video just after the picture of the satellite weather map, and the narrator says, "This lets the meteorologist see where the good weather is, where the storms are, and how fast they're moving around the world." Pause the video as the clouds appear and the narrator states that, "The water vapor stays hidden in the air until the air cools." Ask students if cooling alone will cause the water to come out of the air as a cloud? Why or why not?
Provide your students with a FOCUS FOR MEDIA INTERACTION, by asking students to write down what they think are all of the conditions they believe are necessary for the formation of clouds, and to check their answers against the next video segment. Start the video and run the program through until the narrator says, " A cloud is just millions and millions of these water droplets." Pause the video to check for the students' results on their predictions.
Provide your students with a FOCUS FOR MEDIA INTERACTION, by asking students to watch for how they might be able to make a cloud in a bottle. Start the video and run through the visual of the cloud in the detergent bottle and the narrator saying, "So this is how clouds float in the sky." Stop the video.
You are now ready to do the Three Clouds Lab Activity.
Upon completion of the Three Clouds Lab activity, you will need access to the Internet to complete the activities for this unit.
Culminating Activity 1:
Distribute 2 copies of any black-line map of the United States for use in this activity. You will need to explain to the class that they are now going to check some of the concepts they have been using in this unit. We are going to go to an Internet site to look at some weather maps based on several different factors in the atmosphere. Bring up the site http://www.wunderground.com/. This is the home page for a series of interactive weather maps at the University of Michigan. Provide students with a FOCUS FOR MEDIA INTERACTION, asking students to check the current status of temperatures in the United States. They are to use their pencils or markers to color in the areas of their map in the same pattern shown on the computer map, showing where it is hottest and coldest. You may wish to discuss concepts of what is happening at different locations in the United States based solely on the temperature map they are generating.
Now ask students to predict where they think the humidity is highest on the map. Provide students with a FOCUS FOR MEDIA INTERACTION, telling them to click on the site's humidity map and color in the humidity levels on their second blank map. You may wish to discuss what factors influence the humidity of an area - such as location (by water or inland), altitude, and latitude. Once students have completed these two maps, ask them what other factors they would like to see before predicting where the clouds are forming. Ask them to predict where they think the clouds are located over the United States. They should need to see a pressure map. These maps can be found at http://weather.unisys.com/. Provide your students with a FOCUS FOR MEDIA INTERACTION, by asking students to check their predictions with the visible satellite maps at the sites listed.
Have students write the scripts for evening news "Extended Weather Forecasts" based on web-based weather data research.
Research the formation of the National Weather Service in the United States.
Sketch the different types of cloud formations to create a cloud chart for use in your weather unit.
Create a cloud bingo game using the Internet as a source of cloud pictures to be "called out" and identified.
Use a helium balloon, string, and a Stopwatch to calculate cloud base height. Tie a long string to the balloon. Use the Stopwatch to time 10 seconds of balloon ascent. Step on the string at 10 seconds. Pull the balloon back down and measure the length of the string. Calculate its rate of ascent. Repeat this several times to obtain an average rate of ascent. Now time the release of the balloon and watch until it disappears in the clouds. Calculate the altitude at which the balloon disappeared.
Invite a local radio or television meteorologist into your class as a guest speaker.
Visit your local National weather station as a field trip.
Investigate other weather information services on the Internet.