How can electricity be produced by a lemon?
A lemon battery is a simple battery made for the purpose of education. Typically, a piece of zinc metal (such as a galvanized nail) and a piece of copper (such as a penny) are inserted into a lemon. The lemon contains citric acid, which will cause the same reaction as other weak acids. Tomatoes and citrus fruits usually contain enough acid to affect the galvanometer..
There are many chemicals that can be used to create a flow of electrons. Try this activity with other citrus fruits. Try it with the juice in a cup instead of using the fruit itself.
- Large, fresh lemon
- Zinc and copper strips
1. Just for fun, let's try to make a battery from a lemon.
2. Make two small slits in the lemon, close together, with the knife.
3. Attach the copper strip to one wire of the galvanometer and insert it into one of the slits in the lemon.
4. Push the zinc strip into the other slit. The zinc strip must not touch the copper strip.
5. Wait a few seconds, and then observe the needle on the galvanometer as you firmly touch the wire to the zinc strip. What happened? Wait a few seconds more and try again.
6. Using information you learned in activities 8.17 and 8.18, explain what is happening.
7. Could you use another fruit such as a grapefruit or a tomato? Try it.