On a recent trip out of the country a chemistry professor found a golden-colored metal coin at a flee market. The person selling the coin priced it at $200, claiming it was pure gold. Being a well-equipped traveler and a chemist, the professor produced his graduated cylinder and electronic balance. The coin had a mass of 18.82 g and raised the water level in the cylinder from 5.2 mL to 7.3 mL. Show, by calculation, why he declined to purchase the coin. What, do you think, the major constituent of the coin was ?