Lead is achemical element in theperiodic table that has the symbol Pb (L.plumbum) andatomic number 82. A soft,heavy,toxic andmalleablepoor metal, lead is bluish white when freshly cut but tarnishes to dull gray when exposed to air. Lead is used in building construction,lead-acid batteries,bullets and shot, and is part ofsolder,pewter, and fusiblealloys. Lead has the highestatomic number of allstable elements - although the next element,bismuth has a half life so long it can be considered stable.

Notable characteristics

Lead has a dull luster and is adense,ductile, very soft, highly malleable, bluish-white metal that has poorelectrical conductivity. This true metal is highly resistant tocorrosion. Because of this property, it is used to contain corrosive liquids (e.g.sulfuric acid). Lead can be toughened by adding a small amount ofantimony or other metals to it. Lead is the only metal in which there is zeroThomson effect. Lead is alsopoisonous.

Applications

• Lead is a major constituent of the lead-acid battery used extensively in car batteries.
• Lead is used as a coloring element in ceramic glazes, notably in the colors red and yellow.
• Lead is used as projectiles for firearms and fishing sinkers because of its density, low cost compared to alternative products and ease of use due to relatively low melting point.^[1]
• Lead is used in some candles to treat the wick to ensure a longer, more even burn. Because of the dangers, European and North American manufacturers use more expensive alternatives such as zinc.^[2]
• Lead is used as shielding from radiation.
• Molten lead is used as a coolant, eg. for lead cooled fast reactors.
• Lead glass is composed of 12-28% lead. It changes the optical characteristics of the glass and reduces the transmission of radiation.
• Lead is the traditional base metal of organ pipes, mixed with varying amounts of tin to control the tone of the pipe.
• Lead is used as electrodes in the process of electrolysis.
• Lead is used in solder for electronics.
• Lead is used in high voltage power cables as sheathing material to prevent water diffusion into insulation.
• Lead is used for the ballast keel of sailboats. Its high weight-to-volume ratio allows it to counterbalance the heeling effect of wind on the sails while at the same time occupying a small volume and thus offering the least underwater resistance.
• Lead is added to brass to reduce machine tool wear.
• Lead sheets are used as roofing material.
• Lead is frequently used in scuba diving weight belts to counteract the natural buoyancy of neoprene wetsuits.
• It is also used in weights used in angling.

Former applications

• Lead was used as a pigment in lead paint for white as well as yellow and red colors. It was discontinued because of the dangers of lead poisoning. However, lead chromate is still in use.
• Lead was used for plumbing in Ancient Rome and water mains and service pipes up until the early 1970's.
• Tetraethyl lead was used in leaded fuels to reduce engine knocking; however, this is no longer common practice in the Western world due to health concerns.^[3]
• Lead was used to make bullets for slings.
• Lead was formerly used as a component of toys, though due to many toy safety regulations, this has been stopped.
• Lead is also used at the bass of some metal organ pipes.
• Lead was used in car body filler, which was used in many custom cars in the 1940's-60's. Hence the term Leadsled.

Contrary to popular belief,pencil 'leads' have never been made from lead. The term comes from the roman lead stylus, penicillus. The pencil originated as a wrapped graphite writing tool, a particular type ofgraphite used being named plumbago (lit. acts like lead).