Sink or Swim

Before the meeting:

1. Gather supplies.
2. Print a Sink or Swim Chart for each Cub Scout or use the chart in the Bear handbook.
3. Set up meeting space to conduct experiment including covering the tabletop.

During the meeting:

1. Explain to Cub Scouts that they will be conducting an experiment to see if changing the water will make an egg sink or float.
2. Conduct the experiment with Cub Scouts help:
   • Fill all three cups half full of water.
   • Stir the salt into the first cup and the sugar into the second cup.
   • Leave the third cup alone.
   • On the Sink or Swim chart, have Cub Scouts, write down what they think will happen when adding an egg to each cup. Will it sink or will it swim?
   • Add an egg to each cup.
   • Observe what happens to each egg and ask Cub Scouts to write down the results.
3. Lead a discussion with Cub Scouts:
   • Did your prediction match the actual outcome?
4. Explain to Cub Scouts that this investigation shows how scientists use variables. A variable is something that changes. By changing just one variable at a time, you proved how sugar and salt affect how eggs float. The plain water is called the control because it doesn’t change. Since the control is the same in each cup, we can use it to compare the results with the salt and the sugar