Lead is a chemical element with atomic number 82. Its symbol is Pb.
It is a soft metal, dense, ductile and malleable. It has a white bluish color when just cut, when it is exposed to air it becomes dark gray. Lead is used in construction, in the production of auto vehicle batteries and for firearms bullets, and at the liquid state, it is used a refrigerant in nuclear reactors, sometimes in eutectic alloy with bismuth. Lead is a component of pewter and of metal alloys used in welding.
Both lead and its compounds are harmful, often it even has a relatively low electrical conductivity. It can be hardened with the addition of a small amount of antimony. This alloy has been used for a long time in printing press characters.
It is very resistant to corrosion; it is not affected by sulphuric acid, it melts however in nitric acid. It is believed that all existing lead derived from uranium expiration (U) 238 that transforms into lead (Pb) with a half-
Next to fusion temperature, lead assumes a state defined as "lead blossoming" where it starts to loose its typical opaque color and acquires a shiny color.
The very first pencil models used to have lead instead of graphite leads.
Lead at its native state exists but is rather rare. Generally it is found associated to zinc, silver and mainly copper, therefore it is extracted along these metals. The most important lead mineral is galena (lead sulphide, PbS), which contains 86.6%. Other common minerals are cerussite (lead carbonate, PbCO3) and anglesite (lead sulfate, PbSO4). A great part of lead used today comes from recycled sources, though.