Battery

Purpose:

You will make a simple battery that can light a flashlight bulb or if you put six batteries in series, then you can run a 9 volt radio.

Materials:

• 50 ml beakers or baby food jars

  magnesium strips and copper strips (shine with steel wool or emery paper)

  sodium sulfate solution (71g/liter) or 1/4 teaspoon per jar of water

  wire, flashlight bulb with holder (Radio Shack)

  paper towel

Procedure:

1. Cut the metal strips so they will project one inch above the jar when touching the bottom.

   The ends of the wire should have the insulation removed and be polished with steel wool or emery cloth.

   Wind one wire end around one metal strip. Do the other metal strip the same way.

   Put one magnesium strip into the beaker or jar. Put one copper strip into a different beaker or jar.

   Connect the wires to the flashlight bulb.

   Put the sodium sulfate solution into the beaker or baby food jar filling it 3/4 of the way to the top. Do not allow the solution to touch the wires.

   Connect the beakers or jars with wet paper towel strips (salt bridge) that are 1/2 inch wide with the sodium sulfate solution and put one end into each beaker or jar.

   The light bulb should be glowing.

For the radio do the following:

• Connect the wire from the first magnesium strip to (-) contact of the radio.
• Connect the wire from the copper strip to the magnesium strip of the next cell.
• Keep connecting the copper strips to the magnesium strips of the rest of the cells.
• In the last cell the copper strip should be connected to the (+) terminal of the radio.

Discussion:

If the radio doesn't work, check your setup with the flashlight bulb. If the bulb works, then switch the wires connected to the radio. If the bulb doesn't work recheck all connections and the salt bridges.

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