Shining The Lucky Pennies

Over the weekend my son worked on his science project and he finished it up last night. He was using different household cleaners to see what would shine a penny the best. The idea started after we returned home from Disneyland and he wanted to clean up some of the pennies he had pressed into souvenirs. The results were very interesting and coca cola seemed to work best with out scrubbing and then comet worked with a little elbow grease. I thought for sure the lemon juice would have worked best.