Van de Graaff Generator Demonstrations

See also: Electricity

A Van de Graaff generator is an electrostatic machine that builds up large amounts of static electricity on a metal dome. This category is included because Van de Graaff generators are not always available in classrooms, and it’s valuable to gather all possible demonstrations in one place when access to the equipment is possible.

Demonstration	Materials	Difficulty	Safety	Summary
Van de Graaff Candle	★★☆	★★☆	★★★	A candle placed near the dome of a Van de Graaff generator responds to the electric field by deflecting its flame.
Van de Graaff with Fluorescent Bulb	★★★	★★☆	★★★	A fluorescent light bulb can flicker and glow when brought near a Van de Graaff generator. The strong electric field from the charged dome excites the gas inside the bulb, demonstrating electrostatic discharge and how electric fields can cause visible light emission.
Van de Graaff Flying Ball and Silver Snake	★★☆	★★☆	★★★	A metallized ball or a metallic ribbon (the "silver snake") placed near the dome of a Van de Graaff generator demonstrates electrostatic induction and repulsion. The ball, once charged, floats at a distance from the dome, while the ribbon repeatedly touches and recoils, creating a dynamic “dancing” effect.
Franklin’s Bells With Van de Graaff Generator	★★★	★★☆	★★★	A small conductive ball swings back and forth between two metal plates, alternately charging and discharging as it contacts each plate.
Van de Graaff Pie Tins	★★☆	★★☆	★★★	A stack of aluminum pie plates placed on top of a Van de Graaff generator’s dome will charge and repel each other. As the generator accumulates charge, the plates lift off one by one, demonstrating that like charges repel.
Van de Graaff Sparks	★★☆	★★☆	★★★	A Van de Graaff generator builds up static electric charge on its dome using a moving belt. When a grounded conducting rod is brought close, sparks jump between the rod and the dome. These sparks are similar to miniature lightning bolts and are accompanied by cracking sounds caused by rapidly expanding heated air.
Van de Graaff and Soap Bubbles	★★★	★★☆	★★★	Soap bubbles blown toward a Van de Graaff generator are first attracted by induction, then repelled after they acquire charge.
Van de Graaff Levitating Foil	★★★	★★☆	★★★	Thin strips of aluminum foil can be levitated and made to spin near the charged dome of a Van de Graaff generator. The electrostatic field induces a dipole in the strip, while ionic wind from the generator provides lift and rotation, creating a dramatic and attention-getting demonstration.
Van de Graaff Hair Raising	★★☆	★★☆	★★★	When a person touches the dome of a Van de Graaff generator while standing on an insulator, the charge spreads over their body and onto their hair. Each hair strand, carrying the same type of charge, repels the others, causing the hair to stand on end.
Van de Graaff Confetti	★★☆	★★☆	★★★	When confetti is placed on the dome of a Van de Graaff generator, the pieces quickly become charged and repel each other. This causes the confetti to jump, scatter, and sometimes hover above the dome, vividly demonstrating that like charges repel.
Van de Graaff Human Chain	★★☆	★★☆	★★★	When people form a chain holding hands, with one person touching the dome of a Van de Graaff generator, the charge spreads through every person in the chain. If the last person in the line brings their free hand near a grounded object, all people in the chain receive a shock.

Materials
★☆☆ Easy to get from supermarket or hardware store
★★☆ Available in most school laboratories or specialist stores
★★★ Requires materials not commonly found in school laboratories

Difficulty
★☆☆ Can be easily done by most teenagers
★★☆ Available in most school laboratories or specialist stores
★★★ Requires a more experienced teacher

Safety
★☆☆ Minimal safety procedures required
★★☆ Some safety precautions required to perform safely
★★★ Only to be attempted with adequate safety procedures and trained staff