Penny Baths ~ Science Sunday

This week our experiment together was all about chemical reactions. We have plenty of dirty money around our house {pennies that is}, so we decided to give them a bath in a few different solutions and see what would happen.

If you’d like to try this experiment at home, you’ll only need a few simple things to try it yourself:

• salt
• white vinegar
• dirty pennies
• a glass jar
• a Tablespoon to measure
• a plastic spoon
• paper towels
• bowl of water

Before starting our experiment, the kids made a prediction about what would happen when pennies were washed with a mixture of vinegar and salt. Would they sizzle, turn black, bounce up and down, or become shiny? Predictions varied with our three ~ black, bouncing and shiny {only McKenna guessed correctly}.

We also tried putting just salt on one penny and just vinegar on another to see what would happen. The salt just rubbed off and the vinegar started brightening the penny, but didn’t do a very good job.

The kids measured and mixed 6 Tbsp. of white vinegar with 2 Tbsp. of salt. They took turns stirring and stirring, meanwhile peeking to see what was happening inside the swirling mix.

Each of the kids drew a picture of what happened during the experiment ~ I LOVE seeing their interpretations of what happened! The result? Here are the before and after pictures of Laurianna’s two pennies.

The Nutshell Reason…

Pennies become dull looking because the oxygen atoms in the air combine with the copper atoms on the pennies. When we mixed the salt with the vinegar, a chemical reaction took place. Together the two different items formed a new chemical called hydrochloric acid. When hydrochloric acid meets oxygen atoms on the surface of the pennies, it makes them shiny and looking new.

Resource: How to Do Science Experiments with Children is available from Amazon and you can also check it out {and do some of the experiments} using Google Docs! The experiments use easy-to-find objects and also include record sheets for kids to fill out with their predictions and experiment results. Each experiment also includes teaching tips and explanations…which are rather handy! :)

Don’t forget to check out some other great science ideas at Science Sunday hosted by Ticia at Adventures in Mommydom.