The objective is to describe the mechanisms of heat transfer by conduction, convection and radiation. The tool will be used to establish the definitions of the three types of heat transfer; to implement an interactive power point which students will complete and to physically demonstrate the three types of heat transfer through popping corn (and eating it afterwards!)
This power point is both interactive and instructional; it includes explanations and descriptions and it incorporates review questions throughout.
Understanding Heat Transfer, Conduction Convection and Radiation, retrieved November 16, 2009 from
education.jlab.org/jsat/powerpoint/0708_conduction_convection_radiation.ppt
The lesson would use a demonstration as a tool for understanding: popcorn is popped in three different ways, demonstrating the three types of heat energy transfer:
Conduction, Convection, and Radiation; Popcorn Lesson (Three Methods of Heating), retrieved November 16, 2009 from http://aspire.cosmic-ray.org/labs/atmosphere/popcorn.html
The learning context of this tool is 4th-6th grade classrooms, though it could be adapted for other grade levels. The topic unit which would include this tool is heat and temperature; it could be used as an informal instruction, including reinforcement and self-assessment. This tool would be a good starting activity or introduction to the subject of heat and temperature. Following the use of the tool, the teacher should involve students in making connections between these concepts and the world around them; students should be able to understand the idea of heat energy transfer and they should be able to correctly identify examples of heat transfer they obsserve in everyday life. Before using this tool, students need only be aware that heat does move or transfer from one object to another and they should understand there are different means to accomplishing that transfer.
1. Introduction of the concept of heat energy transfer.
2. Definitions covered.
3. Computer lab time to complete power point.
4. Classroom time for popcorn popping.
5. Follow-up connections.
Safety issues do apply in the popping of popcorn. This could be addressed simply by the teacher doing the popping with oil, or it could be used as a lab activity in which students use saftey goggles and learn the proper, safe technique of old-fashioned popcorn popping. Precautions need to be taken with the air popper, so that students understand not to take off the lid during popping or overfill the popper. They need to know that unpopped kernels are extremely hot and should not be quickly touched. Cautions involving microwave popcorn include proper use of the microwave oven so that the popcorn doesn't burn and opening the heated package properly so that no steam burns occur.
The only ethical issue is to make sure there is enough popcorn for everyone in the class!
This tool is easy to use and to implement. The teacher must have prepatory information with which to introduce the lesson and she will need to schedule time in the computer lab in order for students to complete the power point activity. Prior arrangements and/or permission must be obtained for popping corn.
The tool thoroughly covers the concept of heat transfer. It does address the following ideas:
The tool is complete because the information is thorough and it covers auditory, visual and tactile learning styles; more students have the opportunity to gain understanding and to apply the concepts. The information in this tool is basic and could be followed-up with more in-depth information as needed.
The tool is effective in helping the learner master the objectives because there are three layers to the tool: oral instruction, interactive auditory and visual stimuli (power point) which tests and reenforces key concepts and tactile application of concepts (popping corn) and real life connections as a follow-up. Targeted learners of different abilities and interests may be bored depending on the particular aspect of the tool in use. However, because the concepts are addressed in different ways, the students are more likely to make various cognitive connections through the use of the tool. Student misconceptions may involve a lack of understanding about atoms; the ways in which atoms function; confusion about the difference between heat and temperature. The tool should spark conceptual change by enlightening student's minds to what is really happening when they observe an everday occurrence; they can then begin to question other physical occurrences they observe and use critical thinking in determining the cause and effect of phenomena they observe.
The cost involved in the use of this tool is fairly minimal: possibly ten dollars for popcorn, a few tablespoons of oil and some disposable bowls. Paper towels from the classroom can be used both for holding popcorn and for napkins to further reduce costs. The cost in time is approximately a two-day lesson, including application. Instruction and lab time have the highest time expense; the popcorn demonstration may be incorporated into snack time. The tool's costs are justified compared with alternative tools requiring more lab time or equipment; lab time can be used as a cross-teaching resource with computers as well as physical science and the concepts taught will meet required state standards in science.