Did you know that a lemon can power a clock and light up LED lights? Check out these fun lemon experiments, and try a couple tasty lemon recipes as well! My ten-year-old daughter Emma also wrote up an explanation of how the experiments work for you to read.
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Fun Ways Kids Can Learn with Lemons
This month we were lucky enough to try out the new Green Works StemBox subscription service. I wrote a post last year about how Green Works is working to get more girls interested in STEM (Science, Technology, Engineering, and Math) fields; this subscription box is part of that outreach program!
Green Works has a great reason to be interested in attracting and keeping women in STEM fields. The team that created the laundry and household cleaners that make up the Green Works line was headed up by female scientist Maria Ochomogo. A portion of the proceeds from each March Green Works StemBox subscription will be donated to AAUW, The American Association of University Women, to continue their work of empowering women and girls through advocacy, education, philanthropy and research.
Here is what our StemBox came with:
We had to supply the lemons, which makes sense because they don’t travel or keep well and are easy and inexpensive to purchase. The science materials in the box can be used over and over!
Here are our experiments, as well as an explanation by ten-year-old Emma of how the experiments work.
Lemon Light Experiment
You are supposed to use four lemons for this experiment, but we had to use five – probably because our lemons were quite tiny! It is pretty cool to power an LED light using only lemons, and Emma enjoyed setting up the circuit.
Lemon Clock Experiment
This plug-in lemon clock is more of a demonstration than an experiment, but Emma sure loved it! You can plug this clock into any fruit and it will work – including an apple. We just used lemons because they were out for the other experiment.
Why Do Lemons Work as Batteries?
There are three general things people use when they make batteries: an anode, a cathode, and an electrolyte.
In the lemon clock experiment, the zinc nail was the anode, which is full of negative electrons. The negative electrons want to travel into the positive wire, which is the copper wire. The copper wire is the cathode in the experiment.
The transferring of the electrons in the experiment is what makes electricity to power the lightbulb. The electrons in the zinc nail are used up when they are transferred from the anode to the cathode and then there aren’t any more to transfer. That is why we have an electrolyte, which is the lemon.
The citric acid in the lemons can make more electrons by breaking the bond the zinc electrons already have with protons in the nail through oxidation.
Oxidation frees the protons from the zinc nail. The electrons that already traveled to the copper wire will pull the protons towards them, creating a continuous cycle.
Alessandro Volta followed this same principal when he created the first electrical batter in 1800, although he used salt water instead of lemon juice as his electrolyte.
Bonus Experiment: Lemon Writing
This experiment didn’t come with the kit, but it is a lot of fun and very easy. Parental supervision is important for this one! Write the message using lemon juice (Q-tips work well for this part), then hold it over a tea light until it shows up. Be careful not to catch the paper on fire! It can take a while for the writing to show up, but it is neat when it does!
I’m all about avoiding waste! Once you complete your experiments, try using your lemons in some of these delicious recipes:
- Homemade lemonade. Mike makes this with the kids pretty frequently; this post includes our favorite recipe.
- Make Lemon Cookies. I got this recipe from my sister, who came up with it after trying several different lemon cookie recipes. It is delicious!!!
Ten-year-old Emma LOVED this Green Works StemBox – and it was a great way to learn with lemons! The other kids were all busy with another activity, but I’m sure we will be pulling the materials out to repeat the experiment with them sometime soon.
Do you have a favorite lemon-based learning activity for us to try? How about a lemon recipe?
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