Tasting is Believing

• Roll the lemon, pressing down on it as you roll. Don't press so hard that you break the skin, you just want to squeeze the lemon enough to release the juices inside. Insert two different kinds of metal wire into the lemon. Try zinc and copper wires. Bare the ends of the wire before poking them into the lemon about one inch apart. Touch the two wires to your wetted tongue. What do you feel? That is the flow of electricity. Describe the feeling.
  
  

Measuring the Voltage

• Use a multimeter to test the voltage flowing between the electrodes pushed into the lemon. The voltage reflects how fast the electrons are moving from one electrode to the other. Attach the red alligator clip to the copper wire and the black alligator clip to the other wire. Turn on the multimeter, set it to test DC voltage and read the display. Does the voltage stay steady? Read up on the voltage in your house. How does your lemon battery compare?
  
  

Light an LED Bulb

• Connect the wire leads from your lemon battery to the wire legs of a small LED light. Twist the wires together. You can add a wire cap connector or use electrical tape if the wires won't stick together. Did the LED bulb light up when you touched the second pair of wires together? Was it a strong light? Note: the smaller the light, the better, because your lemon battery doesn't have enough "juice" to light a bigger light.
  
  

Adding Lemons

• Consider what might happen if you connect two or more lemon batteries together. Test your theory out by linking a copper electrode from one lemon to the zinc wire on another lemon. Now connect your LED bulb to the two free wires. Does the bulb light up? Is it just as strong, stronger or weaker? Remove the LED bulb and attach the multimeter to your two-lemon battery. What is the reading now? Is it stronger, the same or weaker? What do you think will happen if you use more lemons? Try it. Record your observations and the data you got from the experiments. Older students can graph the multimeter reading against the number of lemon batteries. How many lemon batteries would it take to equal the current in your home?