How to Make a Lightbulb With a Lemon

With a little chemistry, this lemon could be a battery.

The amount of chemical power contained in a single lemon is enough to produce electricity that you can use for school projects, to just have fun with science or even to make your own sustainable energy source. The citric acid of a lemon provides a metal, in this case zinc, a way to exchange electrons in an oxidation-reduction reaction. This produces a current that can be used to light a small lightbulb.

Things You'll Need

• Zinc nail
• Copper nail
• Copper wire
• Small light bulb

Instructions

1. Roll the lemon on a flat surface with your hand to squeeze the acidic juices from the fruit without puncturing the lemon.

2. Push the zinc nail into one side of the lemon and leave about 2 inches of the nail exposed. This nail will act as the anode, or negative electrode.

3. Push the copper nail into the other side of the lemon and leave about 2 inches of the nail exposed. This will act as the cathode, or positive electrode.

4. Wrap one end of the copper wire around the exposed part of the copper nail.

5. Connect the copper wire to the light bulb midway along the length of the copper wire.

6. Wrap the opposite end of the copper wire around the exposed portion of the zinc nail to complete the circuit and allow the generated current to light the bulb.

Tips & Warnings

• Experiment with different citrus fruits and light bulb voltages to get the desired shine.

• If the copper cathode is not used, flammable hydrogen gas may be produced when the circuit is completed.

References

• "Chemistry: A Molecular Approach"; Nivaldo J. Tro; 2008
• MadSci Network: Food Batteries

Resources

• Science Buddies: Veggie Power! Making Batteries From Fruits and Vegetables