Bing! Bang! Boom!

Summary

The activities in this lesson will help students better understand heat energy, conduction, convection, and radiation.

Materials

Activity #1
For each group:

• Container
• Paper towels

For each student:

• Ice cube

Activity #2
For each group:

• Set of two clear plastic cups
• Thermometer
• Container of ICE cold water (0ºC)
• Blue food coloring
• Container of ROOM TEMPERATURE water (23-25ºC)
• Container of BOILING water (90-100ºC)
• Red food coloring
• Paper towels

For each student:

• Clear plastic cup (5 oz.)
• Small syringe

Activity #3

• Solar bag
• String

Additional Resources

Books

• Elmer in the Snow, by David McKee (Lothrop, Lee & Shepard Books); ISBN 95077472

Teacher Resource Books

• Convection: A Current Events, (GEMS, http://www.lhsgems.org, 510-643-0309); ISBN 0-912511-15-X
• Hot Water and Warm Homes from Sunlight, (GEMS, http://www.lhsgems.org, 510-643-0309); ISBN 0-912511-24-9
• Primarily Physics: Investigations in Sound, Light, and Heat Energy, (AIMS, http://www.AIMSedu.org, 1-888-733-2467); Item 1104

Videos

• Heat, by Bill Nye (Disney Educational Productions, 1-800-295-5010, http://www.dep-store.com/ProductDetails.asp?ProductCode=77C20VL00/index); Product ID: 68A71VL00
• The Transfer of Energy, (Schlessinger Media, 1-800-843-3620, http://www.libraryvideo.com); N6667



Background for Teachers

Heat Energy
Particles that make up substances are always moving and always have energy. This energy can be transferred from one object to another by three means--conduction, convection, and radiation.

There is a difference between heat and temperature. Heat is the energy that the object has because the particles are moving. Temperature is a way of measuring heat energy. Two scales that are commonly used to measure heat are the metric system and the standard system. The metric system uses Celsius (ºC), and the standard system uses Fahrenheit (ºF) to measure heat. The measurement of temperature gives the average amount of energy contained in the substance.

Heat always travels from hotter to cooler objects. It may seem that when you are holding an ice cube, the ice cube is causing your hand to feel colder. However, the real physics behind this heat transference is: The feeling of coldness in your hand is caused by the heat flowing away from your hand and into the ice cube. REPEAT: Energy from the faster moving (hotter) particles transfer to the slower (colder) particles. The transfer of energy goes on until all the particles in both objects are moving at about the same speed. When the amount of heat energy of each object is the same, both objects will have the same temperature.

Conduction
When two objects come into contact with each other, heat energy moves between them because the particles in one object collide with, or 'bing,' the particles in the other object. Transferred heat resulting from the collision of particles is called conduction. Conduction works best through solids, especially through materials such as metals. An example includes observing a raw egg fry as it hits a heated frying pan.

Convection
Heat energy transferred by the movement of a liquid or gas is called convection. When particles are heated, they move faster, expand, become less dense, and 'bang,' the particles rise. As the liquid or gas cools, the particles move slower, contract, become more dense, and 'bang,' the particles sink. This movement of heating, expanding, rising, cooling, contracting, and sinking is a continuous one. An example is to observe the amount of wind in the early morning compared to the afternoon. Wind is an example of a convection process in motion.

Radiation
Conduction and convection need a medium to transfer heat energy; however, radiation does not. Radiation uses electromagnetic waves such as ultraviolet, visible, infrared, and microwaves, 'boom.' These invisible waves carry energy through empty space, as well as through solids, liquids, and gases. All objects give off electromagnetic radiation, which means warm objects emit more radiation than cool objects. An example is the radiation from a campfire making you feel warm as you roast marshmallows.




Intended Learning Outcomes

1. Use Science Process and Thinking Skills
3. Understand Science Concepts and Principles
4. Communicate Effectively Using Science Language and Reasoning
5. Demonstrate Awareness of Social and Historical Aspects of Science
6. Understand the Nature of Science




Instructional Procedures

Invitation to Learn
Set up a microwave oven in front of the classroom and pop a bag of popcorn. Ask students several questions relating to what's going on inside the microwave oven.

Sample Questions:

1. What type of energy is a microwave using?
2. Why does it pop popcorn? Where did the energy come from?
3. Why does the bag feel hot when you first pull it out?
4. Why should you wait a few minutes before eating the popcorn?
5. Where did the steam vapors come from?
6. Feel the air just above the bag as you open it. Why is it warmer than the surrounding air?

During this discussion, list student ideas on chart paper. Revisit this list at the end of the heat unit.

Instructional Procedures

Activity #1--'BING'--Melting Ice Using Conduction
Activity Time: 20 minutes

1. This is a short demonstration with room temperature water and ice. Using a thermometer, take the temperature of a glass of room temperature water. Add several ice cubes to it and let set for a few minutes. Take the temperature of the water after having ice added to it. Have a short discussion about the following question: When you add ice to warm water, does the warm water melt the ice or does the ice make the water colder?
2. Explain to students that they are going to see who can melt an ice cube the fastest using only their hands.
3. Give a container to each group of students filled with enough ice cubes for every student to have his/her own.
   Option: Place each ice cube in a Ziploc bag.
4. Explain to students that they will all begin at the same time.
5. Give the signal to begin.
6. After the initial mayhem and students are complaining about their hands freezing, ask students why their hands are so cold? Ask if the ice made their hands cold or did the heat from their hands cause the ice to melt? Ask how this experience relates back to the initial question about the ice and water.
7. Ask students what would eventually happen to the temperature of the ice water if left alone for 24 hours.

Activity #2--'BANG'--The Effect the Convection Process has on Patriotic Water
Activity Time: 75 minutes

Advance Preparation
Ice Water
The night before, freeze a large block of water (or several trays of ice cubes) dyed with blue food coloring. In the morning, place blue ice in a pitcher and pour a small amount of water over ice. Allow ice to melt into a liquid state but keep as close to 0ºC as possible. When pouring out ice water for each group, it is recommended that you use Styrofoam® cups.

Room Temperature Water
In the morning, fill enough clear plastic cups 2/3 full so that each group has two cups as well as each individual student having one cup. (Example: If you have 30 students, you will need 30 cups, plus enough for each group to have two additional cups.) Water needs to be at room temperature and not right out of the tap.

Note: It is suggested to make several extra for those students who need a "do over."

Hot Water
Just prior to the activity, bring a pitcher of water to a boil and add red food coloring to it. Caution students to be careful!! When pouring out hot water for each group of students, it is recommended that you use Styrofoam® cups.

Procedure

1. Give each group two plastic cups filled with room temperature water, a container of ice water, and a container of hot water. Have students take the temperature readings for the ice water and the hot water and record their data.
2. Give each group a syringe and discuss the appropriate use of this instrument. Use the syringe to measure out 30ml of ice water from the container and slowly put in one of the plastic cups containing room temperature water. Have students make and record observations of what happens to the ice water.
3. Have another person from each group use the syringe to measure out 30ml of hot water from the container and slowly put in one of the plastic cups containing room temperature water. Have students make and record observations of what happens to the hot water.
4. Discuss in detail student observations on how the ice water reacted and the hot water reacted in room temperature water. Ask students why each type of water reacted the way it did. Use this opportunity to connect with the convection process and the movement of particles.
5. Explain to the students that they will be making a patriotic cup with layered red, white, and blue water. Emphasize to the students that each layer is just water and that the amount of heat energy is the only difference in the water's behavior.
6. Discuss effective strategies on how to use the syringe to get the best results. (Creating purple water is not the objective.)
7. Before students begin layering their water, have them take the temperature reading of the room temperature water and record this data.
8. Once students have their water layered in red, white, and blue, have them draw diagrams of their observations in four 15-minute internals.
9. After each 15-minute internal, have a short discussion about what students are observing. Direct their focus on how the ice and hot water's behavior is changing over time. Ask students why the blue ice water is rising. Why is the red hot water sinking? What will your water look like after 45-minutes? What effect is the convection process having on layered patriotic water?
10. After 60-minutes, have students take the temperature of their now 'purple' water. Have students explain this temperature reading relating it to the convection process.

Activity #3--'BOOM'--Make It Fly With Radiation
Activity Time: 30-minutes

A warm, sunny day is recommended to do this activity.

1. Take students outside on the playground and have them sit in a circle.
2. Unfold the black deflated solar bag in the center of the circle.
3. Ask students to problem solve variables to be considered in order to make the black solar bag fly.
4. Choose one student to take the solar bag and run with it. When it is full of air, tie off the ends.
5. Place the semi-filled solar bag in the middle for further observations.
6. As the sun heats the air inside the solar bag, have students record in their journal what is happening and encourage them to make conjectures explaining what is happening in regard to conduction, convection, and radiation.
   Note: Make sure to tether the solar bag with string so it does not fly away--especially with wind present.
   Caution: Read all safety directions on your solar bag.
7. Have several students share their conjectures and discuss how the three means of heat transference all work together simultaneously to make the solar bag fly.



Strategies for Diverse Learners

1. Ask for parent volunteers to supervise small work groups.
2. Pair students with special needs with peers who can help during group activities.
3. Diagrams or explanations: Use short phrases with key words listed on the board. Verbal clues help with definitions.



Extensions

• For a summary review, complete a hierarchy graphic organizer.
• Take the major big ideas regarding heat and have students create pages (using 18” x 24” construction paper) that will be combined into a class Big Book of Heat.
• In cooperative groups, students complete poster displays explaining how the three types of heat transference are involved with situations such as:
  • a candy bar melting in the car
  • a space heater warming up a room
  • a frying pan cooking a grilled cheese sandwich
  • a popsicle melting on the asphalt
• Have students write a reflection essay explaining why popcorn pops in microwave and how the three types of heat transference are involved in the process.

Family Connections

1. Over a seven-day period, have students keep a running list of examples of heat transference observed at home, with a short justification and explanation for each.
2. Have students become the science teacher at home by having them replicate the popcorn in the microwave activity for their families. Have the students then ask family members to explain why a microwave can pop popcorn.
3. Discuss with students the accessibility of electrical energy and the ability to survive without it. Have students design a home project that will assist people in time of power outages to have access to energy using simple heat transference. Projects could focus on helping people cook their food, heat water, keep warm, etc.



Assessment Plan

Performance Task

• Have each student make a solar oven out of a pizza box. Encourage students to make at least one modification from the instructions to make their solar ovens more effective.
• Place a thermometer in each solar oven. Take a temperature reading prior to going outside and after the solar oven has been sitting in the sun for at least 30 minutes. Record data. Caution students not to pick up metal thermometers after solar ovens have been outside for any length of time.
• Give each student the makings for a S’More and a small plate. (They get messy!) Have students predict which will melt first: the chocolate or the marshmallow. Have students place their S’Mores in their solar ovens and make four observations: once every five minutes over a 20-minute period.
• After eating their S’Mores, have students explain in detail how the heat transference of conduction, convection, and radiation are all involved in cooking the S’More. Include in the explanations which melted first and why. Have students use science language and the basic concepts learned about heat. Encourage students to include diagrams with the explanations.

Resource Site
Make A Pizza Box Solar Oven

Suggested Constructed Response Activities
Choose one or more teacher demonstrations to do in front of the class. Have students explain the science behind the demonstration(s) using science language and the basic concepts learned about heat. Encourage students to include diagrams with the explanations.

Suggested demonstrations:

1. Heating up a metal rod on a stand with attached wax balls.
2. Compare the following methods of melting an ice cube:
   1. Place an ice cube under a heat lamp for several minutes to cause it to melt.
   2. Place an ice cube in a large tub, pour a bucket of cold water over the ice cube.
3. Explain a wind machine.
4. Heating up a metal ring and ball set.
5. Galileo’s Thermometer
6. A radiometer