Safety Note: Only use a high-quality glass beaker or liquid
measuring cup (such as Pyrex) for this experiment! An ordinary glass jar or drinking glass will likely crack under this
amount of heat. Never put a glass container directly onto the stovetop!
Procedure:
Light the candle wick and let it burn for about 20 seconds. Carefully
tilt the candle over the beaker, dripping wax inside. You'll need 2-3
teaspoons of wax at the bottom of the mug. Blow out the candle.
Allow the melted wax to cool and harden. Then pour enough sand into the beaker
to cover the wax in a thin layer (about
an inch).
Carefully fill the beaker up with water, taking care not to disturb the
sand. Allow the sand to settle until the water appears clear again (about 30
seconds).
Light the alcohol lamp using a wooden match (Or use an alcohol burner for more speedy results!) and wait for the flame to
stabilize (about one minute).
Place the stand over the alcohol lamp and put the beaker on the stand.
Wait for the contents of the beaker to be heated slowly. For the most
dramatic results, heat slowly over low heat.
As the wax melts, you'll hear a faint hissing sound and see a bulge in the sand layer. Eventually
the bulge will erupt, and hot wax will flow through the sand and the water
to the top of the
beaker.
Explanation:
Volcanoes erupt when red-hot magma seeps up through a vent in the earth's
crust. In this experiment, the wax represents magma from the earth's mantle, and
the sand represents the earth's crust. The water is where the crust and the air
meet. Once a volcano has broken through the earth's crust lava can flow all over
the earth, or it can even be forced out into an ocean. When the wax "magma"
reaches the water, it becomes "lava." Just as the wax hardened once it reached
the water in this experiment, real lava cools and hardens once it reaches
earth's surface.
If you want to see the volcanic reaction again, melt a few drops of wax to
stick the used wax to the bottom of a clean beaker. Cover with sand and water,
then heat slowly as before. The kind of reaction you will get depends on the
levels of sand and wax, as well as how slowly or quickly the alcohol lamp melts
the wax. Try to keep the heat as steady as you can for a more dramatic result.
