How to Make a Potato Clock - Science Project

Safety tip!! Handle the knife with care and get an adult to help you with this step.

1. Carefully cut slits, one in each potato. Then, insert a copper wire into each of the slits.

2. Now insert the nails, one into each potato, on the ends opposite the wires.

3. Open up the battery compartment of the clock and remove the battery if needed. Leave this open because we'll need to connect the wires to the metal.

4. Using alligator clips, connect the wire from one potato to the positive terminal in the clock's battery compartment.

5. Again, with alligator clips, connect a wire from the nail in the other potato to the negative terminal in the clock.

6. Lastly, connect the nail on the first potato to the copper wire on the second potato.

Experiment setup

7. Observe what happens to the clock. Does it turn on?

You need to use the exact metals suggested here, copper and a nail covered in zinc. A steel nail will not work. Make sure all the connects of the wires and clips are secure. If your wires are loosely connected, the electricity will escape and you won't have enough power for your clock.

If your clock still isn't turning on, test it out with a real battery and make sure that it's operational.

What happened when you connected the circuit?

Batteries run on chemical energy. The chemicals needed are contained in three parts: an anode, an electrolyte and a cathode. The anode contains a chemical that supplies the electrons for the circuit. The cathode is at the opposite end of the battery and contains chemicals that accept the electrons. In between these two parts is the electrolyte. These chemicals react with the anode, which releases electrons. The electrons can't reach the cathode directly though the electrolyte, so they are forced to travel through the copper wire to get there. As they flow through the wire, they generate electricity. The electricity flows through the clock in our circuit, causing it to turn on.

Movement of electrons creates electricity to power the clock