COMPLETE ONE KOOKY COINS EXPERIMENT TO EARN YOUR
SCIENCE FUN FOR EVERYONE: KOOKY COINS BADGE
HOW TO CLEAN A PENNY
Fill the glass about halfway full with vinegar.
Stir in about one teaspoon of salt and mix until it dissolves.
Drop eight to ten of the dirty pennies into the solution.
After several minutes, remove half of the pennies and place them on a paper towel to dry.
Now remove the remaining pennies. Rinse these pennies and place them on a separate paper towel to dry.
Observe the difference between the two groups of pennies.