Halloween Science - Frankenstein!

With Halloween nearly upon us we've been taking inspiration from Tim Burton's latest film Frankenweenie and asking the question: could electricity really bring someone's favourite pet back to life?

While we can't help anyone to make their own real monster (or monster pet), we can show you how to generate your own electricity supply using just a potato.  You will need a few bits and pieces for this experiment.

What you need:

• 2 uncooked, large potatoes
• 2 galvanized nails
• 2 short pieces of copper wire
• 3 crocodile clip/wire units like this:
• Digital clock (if you don't have a digital clock you can use a stopwatch or a calculator)

How to:

1. Remove the battery from the digital clock.
2. Number the potatoes 1 and 2.
3. Insert one galvanized nail in each potato. Make sure you leave a bit sticking up.
4. Insert one piece of copper wire into the opposite end of each potato. Make sure you leave a bit sticking up.
5. Use the first crocodile clip to connect the copper wire in potato one to the positive terminal (marked with a +) in the clock's battery compartment.
6. Use the second crocodile clip to connect the copper wire in potato number two to the negative terminal (marked with a -) in the clock's battery compartment.
7. Use the third alligator clip to connect the nails in each potato.

You've made a circuit! Does your clock light up? Can you set the time?

If you like that battery, try making batteries out of different foods! This video by Monkey See shows you how to make batteries out of potatoes, lemons and vinegar:

What's happening?

The potato works just like an electrochemical battery, which converts chemical energy to electrical energy. The zinc in the galvanized nails undergoes a chemical reaction with the copper wire, even though they aren't touching! This reaction produces electrons. The potato acts as an electrolyte, which means that electrons can flow through the potato. Electrons flow through the potato and through the wires, forming a complete circuit. This current of electrons powers your clock.

Once you have created your own source of electricity, check our our Halloween special about Frankenweenie and Frankenstein to learn how not to use electricity (unless you want to create your own horrible monster).