Geyser - Cyclic hot water fountain

  Geyser   Cyclic hot water fountain   Natural geysers form when underground chambers fill with water and are heated geothermally. When the water is heated to its boiling point, the geyser erupts, spewing its contents, and the cycle starts again.    Ring stand Metal ring Hot plate or other heat source Plastic food container Glass tubing (.5 to 1 meter in length) Boiling or Erlenmeyer Flask One-hole rubber stopper Plumber'sputty Timing device (stopwatch or clock) 1) Drill a hole in the center base of your plastic container (a sharp,...

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Gas Model - Caged molecules do their thing.

  Gas Model   Caged molecules do their thing.    The atomic theory of matter tells us that a gas is made up of tiny particles called atoms (or molecules, which are combinations of atoms), which are constantly in motion, smashing into each other and the walls of their container, if there is one. Here is a highly visual model of this idea.    12 or more Styrofoam balls, approximately 1-1/4 inches (3 cm) in diameter (available in craft or fabric stores), or table tennis balls. A paintbrush. Latex...

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Fog Chamber - Make a portable cloud in a bottle. Now you see it; now you don't!

    Fog Chamber   Make a portable cloud in a bottle. Now you see it; now you don't!   Clouds form when invisible water vapor in the air is cooled enough to form tiny droplets of liquid water. In the atmosphere, this usually happens when moist air cools as it rises to higher altitudes. At higher altitudes the pressure is lower, so that the gas expands, loses internal energy, and cools. You can accomplish the same cooling effect by rapidly expanding the air in a jar.    One 1 gallon (3.S liters) clear glass or plastic jar...

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Far Out Corners - Your experience of the world influences what you see.

Far Out Corners   Your experience of the world influences what you see.    When they first glance at this exhibit, many people say, "What's the big deal? It's just a bunch of boxes." But there are no boxes at all. A closer look reveals that the Far Out Corners exhibit is a cluster of corners lit from below. When you walk past the exhibit with one eye closed, the cubes will seem to turn mysteriously so that they follow your movement.    A large cardboard box measuring about 19 x 15 inches (48 x 38 ...

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Falling Feather - Prove to yourself that Galileo was right!

Falling Feather   Prove to yourself that Galileo was right!    In a famous demonstration, Galileo supposedly dropped a heavy weight and a light weight from the top of the Leaning Tower of Pisa to show that both weights fall at the same acceleration. Actually, this rule is true only if there is no air resistance. This demonstration lets you repeat Galileo's experiment in a vacuum.    A clear, plastic, rigid-walled tube with at least a 1 inch (2.5 cm) inner diameter and at least 3 feet (90 cm) long. Available...

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Fading Dot - Now you see it; now you don't. An object without a sharp edge can fade from your view

Fading Dot   Now you see it; now you don't. An object without a sharp edge can fade from your view.    A fuzzy, colored dot that has no distinct edges seems to disappear. As you stare at the dot, its color appears to blend with the colors surrounding it.    Pink paper (1 sheet). Blue paper dot (about 1 inch [2.5 cm] in diameter). Waxed paper. (5 minutes or less) Use the blue paper to make a 1 inch (2.5 cm) dot, and place the dot in the center of the pink paper. Cover the paper with a sheet of waxed paper....

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