The girls had an opportunity to participate in their very first science fair. We had bought a potato clock kit so I just had them do additional experiments with it and then make a presentation board (that board is actually the backing for an old bookcase that fell apart.) Maybe next year we'll spend a little more time on our project and discuss the scientific method.
The instructions that came with our clock basically said that what makes the electricity for the clock is a chemical reaction between the copper, zinc, and
acidic juice of the potato (or lemon.) So imagine our surprise and consternation when the clock worked when we put the copper and zinc in glasses of tap water, tap water with baking soda in it, and distilled water! In fact, of all the things we tested, the only thing that
didn't work were sticks of butter! I was so confused. My brother explained that it's not the acidic environment that you need, but rather
electrolytes.
So why is it called a potato (or lemon) clock!? Why don't any of the tutorials online talk about making a
Water Clock??!! Perhaps I'll do more research on it later...
In addition to displaying their project, they got to present it to the whole group. They got to go first. Secundus volunteered to do all the talking and she was absolutely adorable! Primus stood up there next to her with note cards to keep her talkative sister on track.
Perhaps the most exciting part was the certificates with
two gold seals they received at the end for participating.
