Today try a sink or float experiment with your preschooler to teach him/her about density, buoyancy, observation and prediction.
You will need:
-a plastic tub, container, or bowl (even the kitchen sink or bathtub could be used).
-Items such as small toys, blocks and small household items. (Suggest items of various materials…wood, metal, plastic, etc.)
-Sink or Float Experiment Sheet
1. Fill the container with water. (Adding food coloring to the water or a little Kool-Aid mix to color the water for added fun.)
2. Talk with your child about the meaning of sink and float. Sink means the object moves to the bottom of the water container. Float means that the object stays on the surface of the water. (If an object is very dense it will sink to the bottom of the container….if an object is byoyant it will float at the surface of the water)
3. Have your child choose an item for the experiement and ask them to predict if the item will sink or float. Record the prediction on the Sink or Float experiment sheet attached below.
4. Then place the item in the container/water and see if his/her prediction is correct. Record your observations on the experiment sheet.
As an extension to this activity try finding a video or article on the computer about Why objects float? or Why objects sink?
Give your child a straw to blow the objects around in the water.
Have your child try to make a “boat” to hold items that sink or use a small boat that your have. How many objects does it take to sink the boat?
Have fun with science!