Lead

General
Name, Symbol, Number	Lead, Pb, 82
Chemical series	True metals
Group, Period, Block	14(IVA), 6 , p
Density, Hardness	11340 kg/m3, 1.5
Appearance	bluish white
Atomic Properties
Atomic weight	207.2 amu
Atomic radius (calc.)	180 (154) pm
Covalent radius	147 pm
van der Waals radius	202 pm
Electron configuration	[Xe]44f14 5d10 6s2 6p2
e- 's per energy level	2, 8, 18, 32, 18, 4
Oxidation states (Oxide)	4, 2 (amphoteric)
Crystal structure	Cubic face centered
Physical Properties
State of matter	Solid
Melting point	600.61 K (621.43 °F)
Boiling point	2022 K (3180 °F)
Molar volume	18.26 ×1010-3 m3/mol
Heat of vaporization	177.7 kJ/mol
Heat of fusion	4.799 kJ/mol
Vapor pressure	4.21 E-07 Pa at 600 K
Speed of sound	1260 m/s at 293.15 K
Miscellaneous
Electronegativity	2.33 (Pauling scale)
Specific heat capacity	129 J/(kg*K)
Electrical conductivity	4.81 106/m ohm
Thermal conductivity	35.3 W/(m*K)
1st ionization potential	715.6 kJ/mol
2nd ionization potential	1450.5 kJ/mol
3rd ionization potential	3081.5 kJ/mol
4th ionization potential	4083 kJ/mol
5th ionization potential	6640 kJ/mol
Most Stable Isotopes
iso NA half-life DM DE MeV DP 202Pb {syn.} 52500 y Alpha Epsilon 2.598 0.050 198Hg 202Tl 204Pb 1.4 >1.4 E17 y Alpha 2.186 200Hg 205Pb {syn.} 1.53 E7 y Epsilon 0.051 205Tl 206Pb 24.1% Pb is stable with 124 neutrons 207Pb 22.1% Pb is stable with 125 neutrons 208Pb 52.4% Pb is stable with 126 neutrons 210Pb {syn.} 22.3 y Alpha Beta 3.792 0.064 206Hg 210Bi
SI units & STP are used except where noted.

Lead is a chemical element in the periodic table that has the symbol Pb and atomic number 82. A soft, heavy, toxic and malleable true metal, lead has a dull gray appearance and is bluish white when freshly cut but tarnishes to dull gray when exposed to air. Lead is used in building construction, lead-acid accumulators, bullets and shot, and is part of solder, pewter, and fusible alloys. Lead is the heaviest stable element.

Table of contents

1 Notable Characteristics 2 Applications 3 History 4 Extraction 5 Isotopes 6 Precautions 7 Language Derivations

Notable Characteristics

Lead has a bright luster and is a ductile, very soft, highly malleable, bluish-white metal that has poor electrical conductivity. This true metal is highly resistant to corrosion. Becuse of this property, it is used to contain corrosive liquids (e.g. sulfuric acid). Lead can be toughened by adding a small amount of antimony or other metals to it.

Applications

Early uses of lead included building materials, pigments for glazing ceramics, and pipes for transporting water. The castles and cathedrals of Europe contain considerable quantities of lead in decorative fixtures, roofs, pipes, and windows. Lead is the fifth most widely used metal (in its elemental state) after iron, aluminium, copper and zinc. Common uses include:

• in lead-acid batteries, in electronic components, cable sheathing, ammunition, in the glass of CRTs, ceramics, leaded glass (see glass making), lead piping (not much used these days, although leaded solder was legal for use on drinking water pipes into the 1980s (US)), in paint (banned since 1978 in the US, and gradually in the UK from the 1950s to the 1970s, although older painted surfaces could be up to 50% lead by weight), casting alloys, pewter, solder, and dentistry filling. Also used as flashing on roofing to protect joins from rain. In gasoline (petrol) as tetra-ethyl lead and tetra-methyl lead to reduce knocking (also called pre-detonation, pre-ignition or pinking) from the 1920s, in 1986 leaded gasoline was banned from sale in the United States, in the EU in 1999.

Lead is a superconductor with critical temperature T_c=7.20 K (-265.95 °C).

History

Lead has been used by humans for at least 7000 years, because it was (and continues to be) widespread and easy to extract, as well as easy to work with, being both highly malleable and ductile as well as easy to smelt. Lead was mentioned in the Book of Exodus. Alchemists thought that lead was the oldest metal and associated it with the planet Saturn. Lead pipes that bear