Cleaning Pennies- A Science Activity

Half cleaned penny

Isaiah’s newest obsession is coins, which I find slightly disturbing because they are so dirty and the possible choking hazard. On the other hand, I have to go with it because he is really into them and the potential learning is great.

mixing up 1/4 cup vinegar and 1 teaspoon salt

So the perfect solution (pun intended) was vinegar and salt. Sorry I have to let my inner geek out to play once in a while or it will jump out at the most inopportune moments. Back to your mostly normal blog post….The solution cleans the penny due to a chemical reaction. The kids were fascinated and I was happy to clean the pennies that are living in Isaiah’s hands, his pockets, his bed (I know disgusting), his treasure chest etc.

Kai dips a penny into the solution.

There are many websites describing this scientific experiment. Basically you just add 1/4 cup vinegar and 1 teaspoon of salt in a non-metal bowl. The acidic vinegar and salt remove the copper oxide, which makes the penny dull. Another part of the experiment involves adding something like a bolt to the solution after you clean the pennies and it will turn copper. We might try that next time.

Isaiah cleans his treasured pennies.

The concept of a chemical reaction is probably a little complex for this age group but I think it’s still important to introduce scientific concepts early. They are definitely able to understand something happened. They are also getting used to the scientific process.

I was very impressed when Kai asked if it would work for quarters. It became another experiment with the question, “will the vinegar and salt clean other coins?” They made a hypothesis, they thought it would clean it. They tried to clean a quarter and saw that it did not change the quarter. I love that being right or wrong about your hypothesis isn’t as important as learning something new. Kai documented the results by taking photographs.

Kai documents the experiment with photography.

 

The clean pennies.