Students watch with amazement as warm water rises and cold water sinks in this clever demonstration of density. The demonstration apparatus is a clear acrylic chamber that is divided down the middle with a removable wall. Hot, red water is placed on one side of the chamber and cold, blue water on the other. The center dividing wall is then carefully removed allowing the two solutions to mix. The two different-temperature solutions very dramatically separate with the hot, red water on top and the cold, blue water on the bottom. A great demo when discussing convection currents, air turbulence, and water turnover in lakes and ponds. Comes complete with instructions and teaching information.