Create a visual hailstorm during your electrostatics unit with this demonstration. When small bits of aluminum foil, pith or vermiculite are placed in the cylinder and the upper plate is connected to a Van de Graaff generator, the particles will bounce rapidly throughout the chamber. The particles are first attracted to the upper plate, but after touching it are violently repelled downward where they are once again repelled upward. The net result looks like a violent hailstorm.
The apparatus is 29 cm high and has a 7.5-cm cylinder. It is on its own stand and includes vermiculite and complete instructions.