Sink or Float

Last week, we did a sink or float activity for science. I had everyone gather around the table and I had ten items. Before putting each item in the water, we went around the table asking each child if the particular item would sink or float. We created a chart showing how many children thought each item would sink or float and the real results. The items were:

A cotton ball,

A pompom,

A smaller black rock,

A larger gray rock,

A clam shell,

A leggo,

A cork,

A golf ball,

A plastic turtle shell

And an apple.

I asked the children what sink meant and one child said that it meant where you wash your hands. That was right, but I explained that in this case, it meant that the object would go to the bottom of the bucket. When I asked what float meant, one girl said that it would stay on top of the water. So as the experiment went on, we talked about concepts such as the weight of the different items and heavy vs. light. The children were surprised that the cotton ball appeared to float at first, but then sank to the bottom as it absorbed water. We were all surprised to see the apple stayed afloat. The children really enjoyed this activity so at the end, I let them drop each item in a second time and then help me dry everything off. I'm sure we'll experiment again with different items in the near future. Here is the chart that we made.