Today you can find electric lights of virtually every design and brightness. Although these lights may all seem different, there are really only two types:

1. Fluorescent lights (the long glass tubes) contain a kind of gas that glows when electricity passes through the tube.
2. Incandescent lights (the kind found in most homes, lamps and flashlights) use electricity to heat up a filament.

For a light bulb to work, electricity has to pass through the filament and return to the power source to complete the circuit. Like a battery, a light bulb has two ends, but they sit next to each other. You’ll see a small silver tip. This is a solder connection between one end of the filament and the outside of the bulb.

A second solder at the screw part of the bulb connects to the other end of the filament. The black ring at the bottom of the bulb keeps the two ends of the bulb from touching. To light the bulb, both ends of the bulb have to connect to the two ends of a battery with a wire. Once the circuit is complete, the bulb will light.

Fold the foil in half lengthwise then connect it to the battery and bulb. Remembering that a circuit is a complete loop that electricity can flow through, see how many ways you can connect the bulb and battery to get the bulb to light.