Fun Facts 8

Rolling along...

• A little while ago, we discussed the Periodic Table. Dmitri Mendeleev, a Russian chemist, is the person who is most responsible for the modern Periodic Table, so an element was named in his honor: mendelevium (Md, #101)
• Welders and glassblowers, who work with very bright flames, wear special protective goggles made with didymium glass, which contains praseodymium (Pr, #59)
• Holmium (Ho, #67) oxide has the odd property of appearing light brown in natural light, but red under fluorescent light!
• Toothpaste often contains fluorine (F, #9) because it makes the surface of teeth stronger and more resistant to tooth decay.
• Regular incandescent light bulbs are filled with argon (Ar, #18) gas which helps the filament last longer.
• You might expect that the U.S. nickel (5-cent) coin is made out of nickel (Ni, #28). Actually, it's only 25% Ni (the rest is copper, Cu).
• Many antiperspirants contain a zirconium (Zr, #40) compound that absorbs moisture.
• You may have seen those glasses that change from clear indoors to dark gray outside. They're known as photochromic or photo-gray glasses. Did you know that the color change is due to the presence of silver (Ag, #47) in the lenses? Light causes silver chloride (AgCl), which is clear, to turn into silver metal (Ag), which looks dark.
• Rock layers near the K-T boundary, which corresponds to the disappearance of dinosaurs, is unusally rich in iridium (Ir, #77). Since Ir is more common in meteorites than on earth, scientists believe that the impact of a large meteorite is at least partially responsible for dinosaur extinction.
• Plutonium (Pu, #94) is a very dangerous radioactive element. However, it is used to supply power to spacecraft.