Wednesday, November 19, 2008
General Science: Vanishing ice cubes
This week we started talking about states of matter and observed and documented temperature changes in ice cubes as we heated them in a pot on the stove. At first the kids started off working in pairs, but ran into several problems. I gave each group 2-3 ice cubes and they went from solid to gas in under 3 minutes (the ice, not the kids), plus keeping track of the time and taking measurements was very difficult to do consistently with just 2 people. So while we were able to see that the temperature went up, we didn't learn much about what happened along the way. As a group we brainstormed how to redesign the experiment so that we could see whether the temperature goes up consistently or not. We decided to a)start with more ice, so that is would take longer to melt and b) work as one big group with each kid being responsible for 1 measurement. This worked great and after conducting the experiment, the kids graphed their data and noted some interesting, even surprising results. The temperature did go up, but not in a straight line. Along the way, there were periods of time where the temperature didn't change much at all. Even more surprising was one example of the temperature going down. Were these results because of mistakes we made, or do they reveal something cool about phases changes.....stay tuned!