things you will need
- 4 zinc (galvanised) covered nails
- 4 x 2cm copper wires (or clean pennies)
- 5 croc clip leads
- 4 lemons (or two cut into four)
- 1 x LED (light emitting diode)
- You will need to throw the lemons away after using them in this experiment.
Clean the metal
Use the sandpaper to gently clean the nails and copper wire (or pennies).
Prepare your batteries
- To create a battery we need a positive electrode, a negative electrode, and an electrolyte.
- Give each lemon a rub to help release the electrolytes.
- Push a copper wire or penny into one end of each lemon. The copper wire will be the positive electrode.
- Push a nail into the other end of each lemon. The nail will be the negative electrode.
Line 'em up
- Set up the 4 lemon batteries in a row.
- Connect a red croc clip lead to the copper wire (or penny) in the first lemon.
- Connect a black croc clip lead to the nail in the last lemon.
Connect the batteries
- Using the remaining croc clips connect the zinc nail in lemon 1 to the copper wire (or penny) in lemon 2.
- Repeat until all lemons are connected.
Connect the LED
- Let’s see what happens when you connect an LED.
- Connect the red croc clip connected to the first lemon to the long leg of the LED.
- Connect the black croc clip connected to the last lemon to the short leg of the LED.
You should now be able to see light but what’s happening?
Electrons will always find the easiest path to close the loop. In this case, the easiest path for the extra electrons on the nail is through the LED and into the copper wire.
Try repeating the experiment with different fruits and vegetables. Is the LED brighter or dimmer?