Who knew that those tasty spuds can also do double-duty as an undercover battery? Believe it or not, the common potato has the capacity to create enough electrochemical energy to power a small digital clock. The trace amount of acid and salt in the potato serves as an electrolyte and makes an excellent conductor.
What You Need:
- 2 potatoes (or one potato cut in half)
- 2 short pieces of copper wire
- 2 galvanized nails
- 3 alligator clips
- Piece of sandpaper or steel wool
- Low-voltage LED clock or watch
What You Do:
- Have your child remove the battery from the battery compartment of the clock or watch.
- Ask her to number the potatoes as "1" and "2."
- Insert one nail into each potato, as well as the copper wire.
- Have her use one alligator clip to connect the copper wire in potato number 1 to the positive (+) terminal in the clock's battery compartment.
- Use the other alligator clip to connect the nail in potato number 2 to the negative (-) terminal in the clock's battery compartment.
- Use the third alligator clip to connect the nail in potato 1 to the copper wire in potato 2. What happens?
- Does your child think she can produce more energy by linking potatoes in a series?
- Have her try experimenting with different objects; will a lemon power the clock? How about an orange?