RYNJ students were asked to clean some pennies and figure out which liquid does the best job for a STEAM home assignment. First they were asked to find some dirty pennies. Then they needed to pour a few different liquids like ketchup, Coca-Cola, vinegar, salsa, orange juice or lemon juice into shallow containers or plastic bowls. Students then added a teaspoon of salt to each container, and stirred the salt and liquid together. Then they placed a handful of pennies in each container and let them soak for at least five minutes. Finally they rinsed the pennies in soapy water. Which ones are shiniest? Which are dull? Did any turn green?

Acids are corrosive and sour tasting. Liquids such as vinegar, lemon juice and tomato juice are acids. Pennies are made from copper which tarnishes when exposed to oxygen over time. Placing the copper pennies in an acid will clean the copper oxide off them and make them shiny again.