Element with atomic number 82, element symbol Pb, atomic weight 207.19, mp 327.4°C, specific gravity 11.35. Pure lead recrystallizes at room temperature when deformed. The metal can readily be extruded into pipes or rod but lacks the strength to be drawn into wire. Lead was commonly extracted from galena, lead sulphide, and was often a by-product of the extraction of silver from galena, since many of these lead ores are argentiferous. Lead is a useful addition to bronzes and brasses, especially for making castings and is used as an alloy with tin as a soft solder. The relative abundance of its various isotopes may give an indication as to the source of the metal.