Pathway: Is Aluminum an Electrical Conductor?
Is aluminum an electrical conductor?
- 2 12-inch (30-cm) aluminum foil strips
- duct tape
- size D battery
- 2 spring-clip type clothespins
- short, wide rubber band
- flashlight bulb
- Build a circuit tester (an instrument used to test for the flow of electricity) for use in other sections of the book. Follow these steps:
- Wrap the end of one foil strip around a penny, and tape the foil-wrapped penny to the negative terminal (part of the battery from which electrons leave; flat end) of the battery.
- Open one clothespin and wrap the free end of the foil strip around its tip. Secure the strip to the pin with tape, as in the diagram. This pin will be called the material holder.
- Tape the second foil strip to the positive terminal (the part of a battery toward which electrons flow; raised end) of the battery.
- Place the rubber band around the ends of the battery to securely hold the foil and coin against the battery.
- Wrap the free end of the foil strip around the base of the flashlight bulb. Be careful not to let the foil strip touch the metal dot on the bottom of the bulb.
- Place the foil-wrapped base of the bulb in the jaws of the second clothespin. This pin will be called the bulb holder.
- Lay the foil strip down the side of the bulb holder, and secure with tape.
- Hold the bulb holder, and press the metal bottom of the bulb against the aluminum strip on top of the material holder (the other clothespin).
The bulb glows.
An electrical conductor, such as aluminum, is a material that allows an electric current to pass through it. Conductors, like all matter, are composed of atoms that have a nucleus with positively-charged protons and negatively-charged electrons spinning around the nucleus. Conductors differ from other matter in that they have more electrons called free electrons that are free to move through them. When the conductor is connected to a battery, the free electrons are pushed in the same direction. The path through which the electrons move is called an electric circuit. This movement of electric charges is called an electric current, and since the current moves in one direction it is called a direct current.
- Aluminum is a metal. Are other metals conductors? Repeat the experiment using other metals such as a coin made of nickel (a nickel) and an iron nail. Test each metal one at a time by placing one side of the metal in the jaws of the material holder. Then press the bulb's metal bottom against the opposite side of the metal being tested.
- Do materials other than metals conduct an electric current? Repeat the above experiment using materials such as paper, a wooden pencil, and plastic.
- Would other batteries produce the same results? Repeat the original experiment three times using one of these battery sizes for each experiment: AA, AAA, or C.
- Electrons move through an electric circuit in wire. The repulsion of the electrons at one end of the wire and their attraction at the opposite end of the wire results in the electrons moving in one direction. Prepare a poster to explain the movement of electrons away from the negative end and toward the positive end of the wire.