The U.S. penny is not made of pure copper. The U.S. Mint has changed the penny's composition over the years due to the rising cost of copper. The current U.S. penny is 97.5% zinc and 2.5% copper (copper-plated zinc). Interestingly, the specific heat of copper is 0.385 J/g°C and the specific heat of zinc is 0.387 J/g°C. Copper and zinc have almost identical specific heats, so our experiment today couldn't help show that the U.S. penny isn't pure copper. Can you think of a simple experiment that could be done to show that the U.S. penny isn't made of pure copper? Include relevant data (use internet) about copper and zinc.