The Penny Experiment

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It's President's Day so I thought it was the perfect time to do some penny experimenting (Abraham Lincoln is on the penny, after all!).  The Lil Divas LOVE our experiments, so they were instantly intrigued by the idea of performing some experiments with our pennies. This is another fun & easy experiment/observation to do with the kids at home or school.

Before you begin:

Compare a newer penny to an older one. Ask child why they think the older penny is darker and not as shiny and coppery as the newer penny.  The Lil Divas told me the older pennies were dirty (they are actually covered in copper oxide)

I then asked them to tell me how we could clean the dirty pennies. The Littlest Diva suggested we wash them in water. Building on that the Oldest Diva suggested we use soap & water. I suggested we do both, plus use a special mix that I had in mind and see what happens. They were up for the challenge.

What You Need:

old pennies - the older the better! (we used 40)

3 clear cups

water

dish soap

salt

vinegar (you could also use lemon juice)

What To Do:

1. Fill the 3 clear cups as follows:

fill the 1st w/plain water & add 10 pennies

fill the 2nd w/water + dish soap & add 10 pennies

fill the 3rd w/1/2 cup vinegar + 2 teaspoons salt & add 20 pennies

I took this opportunity to introduce my "special" cleaning mix.

After adding the salt & vinegar into the 3rd cup,

I took one dirty penny and dipped it into the cup half way

so that half the penny was in the mixture & half was not.

after about 10-15 seconds I took it out

& let the Lil Divas observe what had occurred.

We left all the pennies in their cups for 5 minutes. At that time, we came back for a peek and 

took out 10 of the pennies from the salt & vinegar cup and placed them on a napkin (without rinsing or drying them).

After an additional 5 minutes (10 minutes total for the experiment), we came back to see our results.

Results:

The water only cup had no noticeable results.

The Lil Divas thought the pennies in the soap & water cup looked a little cleaner.

The pennies from the salt & vinegar mixture were noticeable cleaner.

(see above comparison to a clean/new penny at bottom of napkin)

Now for an additional experiment:

I rinsed the pennies that came out of the salt & vinegar cup in plain water.

I put them next to the ones we had taken out mid experiment &

invited the Lil Divas to take a look. Here's what they saw:

Pretty cool! It's like what happens to the Statue of Liberty. Why do they turn this bluish-green color? The cooper in the penny reacts with the air (oxygen) and salt and turns the penny green.

Happy Experimenting!

Bern