Sink or Float

I wanted to get the kids more involved in science activities so I decided on an activity to see if things would sink or float. I used a small round container so we could use one object at a time. It was easier for the kids to really observe what would happen that way. Of course, everyone wanted to be the one putting the materials in the container so it was a struggle to convince 12 kids to each take one turn.

I used things like a plastic Easter egg, paper towel, rock, piece of straw, a coin, a paper clip, cotton ball, a piece of tin foil etc. Each child predicted whether the object would sink or float and then we’d put the object in the container. It turned out that most of the kids guessed right. These kids are mostly two and three-years-old, but with older kids you could actually make a graph of their predictions so they could look back and see if what they thought in the beginning was right.

One kid told me that rocks sink because they are heavy. Another kid told me that Easter eggs float because they are light. They learned about absorption. When the cotton ball was light and hadn’t absorbed any water yet, it would float. Once it was filled with water, it was heavy and sank to the bottom. The same thing went for the paper towel. They thought it was cool because it had changed and didn’t go as predicted. Unfortunately, we only had about ten minutes to finish this activity, but they wanted to keep putting the different objects back into the water. This is a simple activity that kids really enjoy.