18. Heavy Metals

They are elements that occupy a select portion of the periodic table and are so essential to America's economic and military might that they are stored in the National Defense Stockpile in case of all-out war. We plan a riveting visit. Some of the vital heavy metals that we survey include copper, uranium, lead, zinc, and nickel. We also take a look at superalloys--consisting of steel combined with chromium, cobalt, and dozens of other heavy metals--that resist corrosion and perform increasingly elaborate functions. From Earth to space, from cosmetics to vitamins, in a million different ways, heavy metals are here to stay!