Cold Water Versus Warm Water (Demonstration)

Density

Purpose:
Illustrate the idea of density of warm and cold water

Safety:
No precautions

Materials:
Colored ice cubes
Warm water
Very cold water
2 eggs
Large clear container

Procedure:
(1.)  Fill a large container with warm water.  Drop in a couple of colored ice cubes, and point out that the cubes float, but as they melt notice the colored water from them sinking to the bottom of the container.
(2.)  Make 2 solutions, one with warm water and the other with very cold water.  Place an egg in each beaker of water; one should float higher than the other.

Explanation:
(1.)  Ice is less dense than water so it floats, but the cool water from the melting ice is more dense than the warm water so it sinks to the bottom of the container.  Good
time to point out how lakes freeze.
(2.)  Since the cold water is more dense than the warm water the egg should float higher in the container with cold water.

Clean-up:
All solutions can go down the drain.  You can still eat the eggs too!

Ginger Chateauneuf, 2000.
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