How can students exemplify their understanding of density through a water experiment?

The choice highlighting how cool water remains at the bottom of a lake effectively demonstrates students' understanding of density. This phenomenon can be observed during different seasons, where the layers of water in a lake do not mix due to variations in temperature and density. In winter, for instance, the surface water may freeze while the cooler, denser water remains at the bottom. This layering effect is critical to aquatic ecosystems, as it influences oxygen levels and temperatures that support marine life.

Utilizing this observation allows students to see firsthand the practical implications of density in nature, showcasing the concept's relevance beyond theoretical definitions. The stratification of water based on temperature and density is a direct example of how substances behave in response to their density, reinforcing their understanding of this key scientific principle.