Powered a Clock with a Lemon (193/366)

“What is a scientist after all? It is a curious man looking through a keyhole, the keyhole of nature, trying to know what’s going on.”
~ Jacques Yves Cousteau


When I was a kid, my grandpa used to show us cool science experiments, but I was also an avid Mr. Wizard watcher and we never could get a chance to do all the awesome experiments we saw on TV.  That’s why I’ve always loved science kits.  N and I found a cool science experiment kit a while ago (one of the experiments I’ve already done with it is the mini volcano) and in it was also another cool experiment I’ve seen but never got to do – powering a clock with a lemon!

We just happened to have a lemon lying around (and of course, two forks), and the kit supplied the clock, connecting wires, and two zinc posts.  I sliced open the lemon and got started.

The circuit starts with connecting the red wire to a fork and the black wire to a zinc post.

Then the white wire gets connected to the other fork, and the other zinc post.

The forks both get stuck into two halves of the lemon, and to complete the circuit, the black wire (attached to the zinc rod) and the white wire (attached to the other zinc rod) will go in.

This was kinda neat – once I stuck the rod with the black wire into the lemon, I got some juice going (ha ha ha pun totally intended) – but not enough to power the clock fully.

Once the second zinc rod went in and closed the circuit, we were in business!

I set the time on the clock (which was actually probably the most difficult thing about this project since there weren’t actual buttons – you had to press the spots where rubber buttons touching the circuitry would have really helped through the protective  plastic covering the clock), and we set up our science experiment on a more stable platform.  I call it “Frankenlemon.”

This project was totally cool, as is this kit.  Being able to do science experiments in your own kitchen is awesome!  This kit is also really neat in that it not only has these different experiments, but it explains the science behind what’s happening, and gives you suggestions for other related experiments as well.  A great learning tool, and super fun, too!  Now to find a place for my new creation …

Related Links:
Kidz Labs Kitchen Science Kit

4 Responses to “Powered a Clock with a Lemon (193/366)”
  1. syingchew says:

    A clockwork lemon?

  2. Tina says:

    Why do we need the white wire connected to the two rods?
    Why does it not work when the red and black wires are connected to the two different rods and inserted into the same lemon?
    Please explain.

    • indt says:

      Hi, Martina!
      The white wire in this example acts as a *second* conductor between the two halves of the lemon (the wires leading to the clock are conducting electricity as well, of course!). I’m not 100% sure, but I believe this second conductive link is needed to boost the electricity created, enough so we can power the clock, since the regular forks called for in this experiment don’t contain a metal that reacts as strongly as others with the acid in the lemon juice. Most “home made” lemon clock experiments call for a zinc item (usually a galvanized nail, which is coated with zinc; we had our zinc rods provided) and a copper item (usually a piece of copper wire; we just used ordinary household forks).

      Copper and zinc, when introduced to the acid in the lemon juice, create separate chemical reactions, generating electricity when they are connected via a conductor. Here’s a cool site with a link to a video explaining more: http://www.techagekids.com/2013/07/making-lemon-battery-and-how-does-it.html

      Thanks for reading and commenting; sorry I didn’t see your comment until today! Hope that additional info helps!

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