PBS
Pbs Teachers: Submarine Race Experiment
Balance the force of gravity with the force of the expanding gasses created by mixing baking soda and vinegar. Create a soda bottle submarine that sinks to the bottom of the bathtub and then rises back to the surface.
HotChalk
Hot Chalk: Lesson Plans Page: Sink or Float?
This lesson plan is designed to have young children explore the concept of sinking vs. floating by using the skills of prediction, observation and classification.