WARNING: DO NOT TRY THIS AT HOME! THIS EXPERIMENT USES 120V ELECTRICAL CURRENT. THIS IS STRONG ENOUGH TO CAUSE SERIOUS INJURY OR DEATH.
Electricity flows through substances known as conductors. Most conductors of electricity are solids, like metal wire. But some conductors can also be liquids. Dill pickles are made by soaking a cucumber in a brine solution high in salt (sodium chloride, NaCl). Salts are ions, atoms or molecules with a positive or negative charge, and they can conduct electricity when in a solution. This is why it is a bad idea to be swimming during a lightning storm!
The pickle has two metal conductors (silver skewers) placed inside of it; parallel to each other, but not touching. The gap between the skewers allows electricity to be conducted through the salty pickle. The skewers are then hooked up to a 120 volt electrical source. The electrical sparks, or an arc, between the skewers excites the sodium chloride ions causing them to emit a light. Sodium produces a yellow light. This is why the sodium vapor lights in parking lots give off a yellow light. If the pickle was made using potassium chloride instead, the light would be pink.
Some pickles seemed to last longer than others. One of our pickles glowed for over seven minutes. The buzzing sound you hear is the electrical arcs going between the two skewers. The electricity heating up the water inside the pickle is what creates the steam that escapes out the sides where the skewers are inserted. The pickle was greatly dried out and blackened on the inside when the experiment was over. Ick!
This demonstration can be seen live during our Electricity and Magnetism school science presentation. Click here for details.
Remember; DO NOT TRY THIS AT HOME!