Get Your Juices Flowing

Your classroom is running out of electricity and the teacher has asked you to help him find a temporary source of energy to get a single light for to help you find your way. That's when you spot the bowl of fruit. Can fruit help the teacher make electricity?

What You'll Need

1 citrus fruit (lemons or limes work best)

1 copper screw about 5 cm long

1 zinc screw about 5 cm long

1 holiday light with 5 cm leads

How it Works

You remember that a battery is nothing more that a device that stores metals and chemicals. And all that citrus contains acids so maybe, just maybe, you can help your poor teacher out.

1. Roll the fruit under the palm of your hand to soften but be careful you don't break the skin. Work it gently on a piece of scrap paper or a paper towel.

2. Insert the screws into the fruit about 5 cm apart. Don't allow the screws to go through the bottom skin of the fruit.

3. Carefully remove about 1 cm of the insulation from the leads on the holiday light. Do not cut into the wire beneath the insulation.

4. Twist one end of the wire around one screw and the other end around the other screw. Presto--you have light!

Investigate the probability of using other fruits and vegetables to make electricity. Measure the pH of each "battery" and see if there is a relationship between the pH of the juice and the amount of light that is produced. If you have a multimeter, you can measure the voltage and current produced.