Lead
Lead, symbol Pb, dense, bluish-gray metallic element that as one of the first known metals. The atomic number of lead is 82; the element is in group 14 of the periodic table. Lead was mentioned in the Old Testament. It was used by the Romans for making water pipes, soldered with an alloy of lead and tin. Few metals have been used in more different ways than lead. Lead ornaments and coins have been in use since ancient times. In the Middle Ages, strips of lead called camas were first used to assemble the pieces in stained-glass windows. In the United States, about two-thirds of all the lead produced is used in electric storage batteries of the kind found in automobiles. Large amounts of lead are used as protective coverings for electrical cables, and there are lead compounds in paints and pigments. The use of lead in paints has been decreasing because lead is poisonous, and many children have been poisoned by eating flakes of dried paint containing lead. Lead bullets and shot made gunpowder effective in firearms. Lead is the main ingredient of solder, used for joining pieces of metal. Metallic lead is a soft, malleable, ductile metal. Lead is the heaviest and the softest of the common metals.
