Heat Transfer

For this inquiry activity I chose to use four materials I thought would insulate, but in varying degrees. One of the difficulties was finding items that could be rubber banded to the mugs to keep the variables consistent. I went with four materials that fit together in pairs. Two were food related, foil and plastic wrap. The next two items were clothing materials, one cotton, the other an exercise material made from polyester. Because the clothing pieces had extra fabric hanging over the side, I carried the material of the other items over the side to keep it as consistent as possible. I chose these items in the hope I could make practical conclusions for the future.

The results were as follows (least to greatest temperature): plastic, cotton, polyester, and then foil. I was somewhat surprised because the foil easily won as the best insulator. Aluminum has a fairly low specific heat and the foil also has no gaps for air pockets. The only thing I can think of is that the aluminum had a higher specific heat than the other materials. I would have liked to have had the time to conduct multiple trials with other materials to see if I continued to get the same results. I did do two trials with foil winning, but one was only “finger” tested because I was having trouble with the thermometer. My thermometer from the science kit was broken, therefore, I was using a digital thermometer. I boiled water to disinfect baby bottles and then used the water from that when I was finished. Some of the cups were too hot to register so I poured them all together, mixed them and reset the experiment at a lower beginning temperature. The plastic did not register in the second experiment because it was too low, but I was able to get data from the others. The cotton and polyester were only one tenth of a degree apart, but the foil was just over two degrees warmer than both of them.

The idea of heat transfer at the molecular level can seem advanced for elementary students, but I think this is the "big idea" I would want them to be introduced to.  They are familiar with vibrations and the book did a nice job of comparing heat transfer from conduction in this manner.  I do not think I would have been able to take this away from this experiment without reading and researching further.  This would be something that would have to be taught by the teacher.