Lead is a metal element denoted by the atomic number 82. Its atomic symbol, Pb, comes from the Latin word plumbum. It is a very soft, highly malleable metal with a bluish-white sheen that tarnishes rapidly to a dull gray. It has an atomic weight of 207.2, a melting point of 621.43°F (327.46°C), and a boiling point of 3180.2°F (1749°C). Lead is primarily found in galena and is often mixed with copper and zinc.

Lead has been in use as a metal since very early times. Lead artifacts from 3800 b.c. still exist. Its softness and relatively low melting point made it an easy metal for ancient technology to work. The Egyptians may have learned to use it as early as 5000 b.c. Among other uses, the Egyptians used a lead oxide, called red lead, as a cosmetic pigment. The Romans used lead for pipes. Alchemists...