In Chemistry, we did a lab involving pennies. First we got a beaker of water, and a chemical that could be mixed together. Then after mixing, you used a burner to heat the water to a boil. Once the chemical started reacting in the water, we had to drop the penny into the mixture. Once the penny touched the chemical, it was supposed to turn into a silver color, like a nickel or dime. Once we realized that our penny had become silver,  we pulled it out of the beaker with tweezers. Then from there you could either keep your silver penny, or you could change it into a different color. We used our tweezers again with the penny on them and ran it across the flame of the burner. This changed the penny into a gold color.  We eventually made several different kinds, and they all turned out amazing.