Students determine whether a liquid will sink or float in water by comparing its density to the density of water.

Students investigate with common objects to see if they can make something that neither floats nor sinks, but rather "flinks" in the middle.

This is an educator's guide for a unit on things that sink or float. It includes lesson plans, experiments, and activities. Students apply the scientific method as they investigate whether objects sink or float.

Become an engineer, and design a submarine that moves in the water like a real submarine. Try making it sink, float, and hover in the water.

Try this at-home science experiment to learn if salt affects the way things float.

Explore the use of ballast to manipulate buoyancy in submarines by building a model of a submersible using two-liter bottles and balloons. Describe the balance of forces that is responsible for the surfacing and diving of submersibles.