After two weeks off (one for behavior issues and one for Science Camp) Molecular Monday returns. Let's be honest for a moment, I was all gung ho when summer started, but now I'm counting the days until school starts again like everyone else. I'm burning out on all this one on one with an angst almost 10yr old. Less than prepared to start this week I picked up a book of Isaac's called The Way Science Works and flipped through it until I found an experiment that didn't require a trip to the store or a big clean up. So "The Effect of Heat on Density" was the winner.
- Large Glass Jar/Vase
- Smaller bottle
- Food coloring
- Tap Water
As usual I found the experiment directions incredibly vague. They simply tell you to fill the larger vessel 3/4 of the way with cold water. So, our first attempt we did just that. It was a flop. It needs to be full enough that the smaller bottle is completely submerged.
Once you've got the larger vessel filled with cold tap water to a level that will submerge your smaller bottle fill the small bottle with hot tap water. Dish washing temperature is perfect. Than secure the string around the bottle and drop in some food coloring. We used yarn and red food coloring. The string is the handle you use to lower the bottle to the bottom of the vase. The food coloring makes the effect visible.
That's all there is to it. Be careful not to tilt your bottle lowering it in. The hot water will escape upward erupting into the bigger container. It slows down and stops as the temperature equalizes.
Why it works:Cold water molecules are closely packed together. They do not have enough energy to move far. As water heats up, the molecules gain energy. If enough heat is applied, they will fly off to become water vapor. The colored hot water rises because it is less dense than the surrounding cold water. The Way Science Works