During this experiment we were learning about water density, and how it is affected by the temperature.
First, we started with a simple sink and float activity. The kids predicted, and then executed the experiment with just a few items. We were surprised to find out the Lego piece was less dense than water.
Next, the kids prepared the materials for the experiment. As a teacher in my own classroom, I always did the preparation, and selection of materials. Having only my two curious kids, I make them do as much as possible. Since none of the water unit experiments can harm them, that means they are doing every step on their own. Above you can see Little Guy building a sinking plastic vial. He wrapped the vial with a popsicle stick, and a rubber band. He also placed blue food coloring to be able to observe how the density of cold water reacts inside room temperature water. Big Sister prepared the hot water using red food coloring.
Both kids practice how to submerge the plastic vials, and position them using a clothespin. At this point, they were only using room temperature. This practice step was crucial to be able to actually observe how density changes with the temperature. They needed to have steady, and quick hands! Otherwise, they could've ended up just spilling all the colored water.
First Big Sister placed her red, hot water in the vial. She predicted that the water was all going to float. Then, she submerge the vial and attached it to the cup using the clothespin. We observed how the hot water is less dense than room temperature water as it went upward right away. It was neat to see how the red hot water went to the top, while the room temperature stay clear at the bottom. She was right on her prediction!
Next, Little Guy predicted that the blue cold water was going to sink. We were surprised to see that the cold water was so dense, it barely moved from the vial! The blue cold water simply stay in its place.
In the above picture, you get to see a comparison of the water density according to temperature. The red hot water was less dense, hence mostly at the top. The blue cold water was more dense and it mostly stay in the vial.