Heat as Energy

I know that a good insulator is something that helps trap heat. I always wondered what characteristics an object must possess in order to be a good insulator. I was glad that I could complete this experiment, because I was hoping that I would be able to figure out an answer to that question. I tested the temperature of the water before I started and it started out at 110.4ºF. I used similar sized mugs and filled them up with the same amount of water, so I could eliminate any possible variables. The four items that I chose to use as insulators were, aluminum foil, plastic wrap, a piece of paper, and a cotton cloth napkin. When I placed the materials over the mugs I made sure to put the rubber bands tightly around them, so that the heat would have a harder time escaping out of the sides. Going into the experiment I definitely expected that the aluminum foil would be the best insulator. I am not sure why I thought that, but that was my first instinct. First I took the temperature of the water in the mug that was covered with the paper. The temperature was 95.3ºF. The second mug that I tested was the one covered with aluminum foil. The temperature was 100.3ºF. Next was the mug covered with the cloth napkin. The temperature was 98.5ºF. Lastly I tested the mug with the plastic wrap. The temperature was 98.2ºF. I was not surprised by some of the results that I found after completing this experiment. I expected that the aluminum foil would be the best insulator and it was. However, I did not expect the paper to be the poorest insulator. I thought that it would be the plastic wrap, because it is so thin, but there was not much difference between that and the cloth napkin.
If I were to do this experiment again I would try to use different materials. I wold be interested to use styrofoam, newspaper, and jean material. I think that the styrofoam would be the best insukator, because it has smaller spaces of air molecules. The heat would have a harder time getting through, so the liquid would stay hotter.