This project needs you to provide a clear explanation of the working principles of electromagnetism. It would be to your benefit to keep photographs and documentation of your project as you create it. An electrolyte is any liquid capable of conducting electricity: 1) Acids-vinegar, lemon, and tomato juice-are excellent electrolytes; 2) Salts-neutral salt (table salt), acid salt (cream of tartar), and basic salt (baking soda). Your project will provide a demonstration of how a coil of wire behaves like a magnet as it carries an electrical current in this simple closed circuit.

MATERIALS NEEDED:

1. Thin copper wire
2. Copper nail or thick copper wire
3. 2 pieces insulated wire
4. Small styrofoam ball
5. Small bowl
6. Sharp pencil
7. Salt
8. 6-volt battery
9. stack of books
10. Masking tape
11. Scissors
 

 
FIRST, twist your thin copper wire around the pencil. This will be a coil, but do not overlap the wire as you twist. Slip the coil off the pencil very carefully. Push your thick copper wire through the styrofoam ball to allow the wire to stick out on both ends. Put the sharp end of your pencil into the cork's side, but tape the pencil's other end to the side of a book. Set this book on the top of the pile of books to allow the styrofoam ball, pencil and wire to hang from the stack of books. It needs to measure around 12.5 centimeters, or 5 inches.

THEN, gently stretch the coil of copper wire so that it acts like a spring. Straighten out each spring end before twisting one of the ends around the thick copper wiring that is at the bottom of the styrofoam ball. You may need an adult to help strip the insulation from the ends of the insulated wire so that you can attach each piece of wire to the battery terminal. Attach the opposite end of one of the wires to the thick copper wire that is sticking out from the ball's top.
 

 
NEXT, fill your bowl with warm water and add salt. You will need to continue adding salt UNTIL NO MORE SALT DISSOLVES. Put the other end of the copper spring in the salt water. It needs to sit just below the surface of the water. The disconnected piece of insulation from the battery needs to slightly dip the stripped end into the saltwater.

You have just created a simple circuit. As you touch the end of the battery-connected wire to the saltwater, the circuit is completed so that electricity travels in a continuous loop. As electrical current passes through the spring, it turns it into a magnet, which has a north and south pole.

Source:

1. Vecchione, Glen. 100 First-Prize Make-It-Yourself Science Fair Projects. Sterling Publishing Comany, Inc.: NY 1999