This lesson will require approximately twenty five minutes.
Some objects sink when placed in water and others float on the surface.
Sometimes when something else is added to the water, like seltzer tablets, it affects what happens to the objects placed in the water. Bubbles are created from the mixture of water and seltzer tablets and these bubbles cling to the surface of the objects. The objects become buoyant and begin to rise to the surface. In this activity, the results of adding something to the water are amusing, as well as instructive. The purpose of this lesson is to help children learn to observe carefully the affect of adding a foreign substance on objects placed in a container of water.