I found the cleaning penny idea at The Science Explorer. We set to work gathering the materials- 20 dull and dirty pennies, 1/4 cup vinegar, 1 teaspoon salt, clear shallow bowl, and 2 paper towels labeled "Rinsed" and "Not Rinsed" (the website suggests doing activities with nails and bolts- we just stuck to the pennies).
Gather your materials. I just love the little Rudolph face in the background! She was our little cheerleader during the activity:)
Stir salt in the vinegar until its dissolved. This was a great time to discuss with Boo what "dissolves" means.
Take a penny and dip it halfway into the vinegar and salt mixture. Count to 10 and...
Half of your penny is clean! So cool!!
After doing this a couple times (since it was super exciting for both of us), dump all your pennies into the vinegar/salt mixture.
After 5 minutes, take half your pennies and put them on the "Not Rinsed" paper towel.
After one hour, the "Not Rinsed" pennies will have a nice blue tint to them! The reason is that the copper atoms are joining with oxygen atoms and chlorine atoms from the salt.