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Encyclopedia > Lead
82 thalliumleadbismuth
Sn

Pb

Uuq
General
Name, Symbol, Number lead, Pb, 82
Chemical series Post-transition metals or poor metals
Group, Period, Block 14, 6, p
Appearance bluish gray
Standard atomic weight 207.2(1) g·mol−1
Electron configuration [Xe] 4f14 5d10 6s² 6p²
Electrons per shell 2, 8, 18, 32, 18, 4
Physical properties
Phase solid
Density (near r.t.) 11.34 g·cm−3
Liquid density at m.p. 10.66 g·cm−3
Melting point 600.61 K
(327.46 °C, 621.43 °F)
Boiling point 2022 K
(1749 °C, 3180 °F)
Heat of fusion 4.77 kJ·mol−1
Heat of vaporization 179.5 kJ·mol−1
Heat capacity (25 °C) 26.650 J·mol−1·K−1
Vapor pressure
P(Pa) 1 10 100 1 k 10 k 100 k
at T(K) 978 1088 1229 1412 1660 2027
Atomic properties
Crystal structure cubic face centered
Oxidation states 4, 2
(Amphoteric oxide)
Electronegativity 2.33 (Pauling scale)
Ionization energies
(more)
1st: 715.6 kJ·mol−1
2nd: 1450.5 kJ·mol−1
3rd: 3081.5 kJ·mol−1
Atomic radius 180 pm
Atomic radius (calc.) 154 pm
Covalent radius 147 pm
Van der Waals radius 202 pm
Miscellaneous
Magnetic ordering diamagnetic
Electrical resistivity (20 °C) 208 n Ω·m
Thermal conductivity (300 K) 35.3 W·m−1·K−1
Thermal expansion (25 °C) 28.9 µm·m−1·K−1
Speed of sound (thin rod) (r.t.) (annealed)
1190 m·s−1
Young's modulus 16 GPa
Shear modulus 5.6 GPa
Bulk modulus 46 GPa
Poisson ratio 0.44
Mohs hardness 1.5
Brinell hardness 38.3 MPa
CAS registry number 7439-92-1
Selected isotopes
Main article: Isotopes of lead
iso NA half-life DM DE (MeV) DP
204Pb 1.4% >1.4×1017 y Alpha 2.186 200Hg
205Pb syn 1.53×107 y Epsilon 0.051 205Tl
206Pb 24.1% 206Pb is stable with 124 neutrons
207Pb 22.1% 207Pb is stable with 125 neutrons
208Pb 52.4% 208Pb is stable with 126 neutrons
210Pb trace 22.3 y Alpha 3.792 206Hg
Beta 0.064 210Bi
References
Lead pipe in Roman baths
Lead pipe in Roman baths

Lead (pronounced /ˈlɛd/) is a chemical element with the symbol Pb (Latin: plumbum) and atomic number 82. A soft, heavy, toxic and malleable poor 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, weights, and is part of solder, pewter, and fusible alloys. Lead has the highest atomic number of all stable elements, although the next element, bismuth, has a half-life so long (longer than the estimated age of the universe) it can be considered stable. Like mercury, another heavy metal, lead is a potent neurotoxin that accumulates in soft tissues and bone over time. General Name, Symbol, Number thallium, Tl, 81 Chemical series poor metals Group, Period, Block 13, 6, p Appearance silvery white Standard atomic weight 204. ... General Name, Symbol, Number bismuth, Bi, 83 Chemical series poor metals Group, Period, Block 15, 6, p Appearance lustrous pink Standard atomic weight 208. ... This article is about the metallic chemical element. ... General Name, Symbol, Number ununquadium, Uuq, 114 Chemical series presumably poor metals Group, Period, Block 14, 7, p Appearance unknown, probably silvery white or metallic gray Atomic mass (298) g/mol Electron configuration perhaps [Rn] 5f14 6d10 7s2 7p2 (guess based on lead) Electrons per shell 2, 8, 18, 32... File links The following pages link to this file: Lead Template:Lead infobox User:Femto/elements e7 Categories: GFDL images ... This is a standard display of the periodic table of the elements. ... An extended periodic table was suggested by Glenn T. Seaborg in 1969. ... This is a list of chemical elements, sorted by name and color coded according to type of element. ... A table of chemical elements ordered by atomic number and color coded according to type of element. ... A group, also known as a family, is a vertical column in the periodic table of the chemical elements. ... The trivial name poor metals (or post-transition metals) is sometimes applied to the metallic elements in the p-block of the periodic table. ... This article does not cite its references or sources. ... A group, also known as a family, is a vertical column in the periodic table of the chemical elements. ... In the periodic table of the elements, a period is a horizontal row of the table. ... A block of the periodic table of elements is a set of adjacent groups. ... The carbon group is group 14 (IUPAC style) in the periodic table. ... A period 6 element is one of the chemical elements in the sixth row (or period) of the periodic table of the elements, including the Lanthanides. ... The p-block of the periodic table of elements consists of the last six groups. ... Color is an important part of the visual arts. ... The atomic mass (ma) is the mass of an atom at rest, most often expressed in unified atomic mass units. ... Hydrogen = 1 List of Elements in Atomic Number Order. ... Electron atomic and molecular orbitals In atomic physics and quantum chemistry, the electron configuration is the arrangement of electrons in an atom, molecule, or other physical structure (, a crystal). ... General Name, Symbol, Number xenon, Xe, 54 Chemical series noble gases Group, Period, Block 18, 5, p Appearance colorless Standard atomic weight 131. ... For other uses, see Electron (disambiguation). ... Example of a sodium electron shell model An electron shell, also known as a main energy level, is a group of atomic orbitals with the same value of the principal quantum number n. ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... This box:      For other uses, see Solid (disambiguation). ... For other uses, see Density (disambiguation). ... For other uses, see Room temperature (disambiguation). ... For other uses, see Density (disambiguation). ... The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ... The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ... For other uses, see Kelvin (disambiguation). ... For other uses, see Celsius (disambiguation). ... For other uses, see Fahrenheit (disambiguation). ... Italic text This article is about the boiling point of liquids. ... For other uses, see Kelvin (disambiguation). ... For other uses, see Celsius (disambiguation). ... For other uses, see Fahrenheit (disambiguation). ... Standard enthalpy change of fusion of period three. ... The joule per mole (symbol: J·mol-1) is an SI derived unit of energy per amount of material. ... The standard enthalpy change of vaporization, ΔvHo, also (less correctly) known as the heat of vaporization is the energy required to transform a given quantity of a substance into a gas. ... The joule per mole (symbol: J·mol-1) is an SI derived unit of energy per amount of material. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Vapor pressure is the pressure of a vapor in equilibrium with its non-vapor phases. ... Enargite crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. ... Amphoteric redirects here. ... Electronegativity is a measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ... The ionization energy (IE) of an atom or of a molecule is the energy required to strip it of an electron. ... These tables list the ionization energy in kJ/mol necessary to remove an electron from a neutral atom (first energy), respectively from a singly, doubly, etc. ... Kilojoule per mole are an SI derived unit of energy per amount of material, where energy is measured in units of 1000 joules, and the amount of material is measured in mole units. ... Atomic radius: Ionic radius Covalent radius Metallic radius van der Waals radius edit Atomic radius, and more generally the size of an atom, is not a precisely defined physical quantity, nor is it constant in all circumstances. ... One picometre is defined as 1x10-12 metres, in standard units. ... Atomic radius: Ionic radius Covalent radius Metallic radius van der Waals radius edit The covalent radius, rcov, is a measure of the size of atom which forms part of a covalent bond. ... The van der Waals radius of an atom is the radius of an imaginary hard sphere which can be used to model the atom for many purposes. ... For other senses of this word, see magnetism (disambiguation). ... Levitating pyrolytic carbon Diamagnetism is a form of magnetism that is only exhibited by a substance in the presence of an externally applied magnetic field. ... // Headline text POOP!! Danny Hornsby (also known as Gnome) is a measure indicating how strongly a Gnome can opposes the flow of electric current. ... K value redirects here. ... During heat transfer, the energy that is stored in the intermolecular bonds between atoms changes. ... This page is about the physical speed of sound waves in a medium. ... For other uses, see Room temperature (disambiguation). ... Metre per second (U.S. spelling: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector), defined by distance in metres divided by time in seconds. ... In solid mechanics, Youngs modulus (E) is a measure of the stiffness of a given material. ... In materials science, shear modulus, G, or sometimes S or μ, sometimes referred to as the modulus of rigidity, is defined as the ratio of shear stress to the shear strain:[1] where = shear stress; force acts on area ; = shear strain; length changes by amount . ... The bulk modulus (K) of a substance essentially measures the substances resistance to uniform compression. ... Figure 1: Rectangular specimen subject to compression, with Poissons ratio circa 0. ... The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. ... The Brinell scale characterises the indentation hardness of materials through the scale of penetration of an indenter, loaded on a material test-piece. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... Lead (Pb) Standard atomic mass: 207. ... For other uses, see Isotope (disambiguation). ... Natural abundance refers to the prevalence of different isotopes of an element as found in nature. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... In physics, the decay mode describes a particular way a particle decays. ... The decay energy is the energy released by a nuclear decay. ... The electronvolt (symbol eV) is a unit of energy. ... In nuclear physics, a decay product, also known as a daughter product, is a nuclide resulting from the radioactive decay of a parent or precursor nuclide. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Alpha decay is a form of radioactive decay in which an atomic nucleus ejects an alpha particle and transforms into a nucleus with mass number 4 less and atomic number 2 less. ... This article is about the element. ... A Synthetic radioisotope is a radionuclide that is not found in nature: no natural process or mechanism exists which produces it, or it is so unstable that it decays away in a very short period of time. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Electron capture is a decay mode for isotopes that will occur when there are too many protons in the nucleus of an atom, and there isnt enough energy to emit a positron; however, it continues to be a viable decay mode for radioactive isotopes that can decay by positron... General Name, Symbol, Number thallium, Tl, 81 Chemical series poor metals Group, Period, Block 13, 6, p Appearance silvery white Standard atomic weight 204. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... Stable isotopes are chemical isotopes that are not radioactive. ... This article or section does not adequately cite its references or sources. ... A trace radioisotope is a radioisotope that is naturally occurring. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Alpha decay is a form of radioactive decay in which an atomic nucleus ejects an alpha particle and transforms into a nucleus with mass number 4 less and atomic number 2 less. ... This article is about the element. ... In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. ... General Name, Symbol, Number bismuth, Bi, 83 Chemical series poor metals Group, Period, Block 15, 6, p Appearance lustrous pink Standard atomic weight 208. ... Recommended values for many properties of the elements, together with various references, are collected on these data pages. ... Image File history File links Metadata Size of this preview: 450 × 600 pixelsFull resolution (960 × 1280 pixel, file size: 577 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Metadata Size of this preview: 450 × 600 pixelsFull resolution (960 × 1280 pixel, file size: 577 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Look up lead in Wiktionary, the free dictionary. ... The periodic table of the chemical elements A chemical element, or element, is a type of atom that is defined by its atomic number; that is, by the number of protons in its nucleus. ... For other uses, see Latin (disambiguation). ... See also: List of elements by atomic number In chemistry and physics, the atomic number (also known as the proton number) is the number of protons found in the nucleus of an atom. ... For other meanings, see heavy metal The term heavy metal may have various more general or more specific meanings. ... // Toxic and Intoxicated redirect here – toxic has other uses, which can be found at Toxicity (disambiguation); for the state of being intoxicated by alcohol see Drunkenness. ... Malleability is a physical property of matter, signifying its capability of deformation, especially by hammering or rolling. ... This article does not cite its references or sources. ... A valve-regulated, sometimes called sealed, lead acid battery Lead-acid batteries, invented in 1859 by French physicist Gaston Planté, are the oldest type of rechargeable battery. ... This article is about firearms projectiles. ... Lead shot is small balls of lead, traditional made using a shot tower. ... A solder is a fusible metal alloy, with a melting point or melting range of 180-190°C (360-370 °F), which is melted to join metallic surfaces, especially in the fields of electronics and plumbing, in a process called soldering. ... Pewter plate Pewter is a metal alloy, traditionally between 85 and 99 percent tin, with the remainder consisting of 1-15 percent copper, acting as a hardener, with the addition of lead for the lower grades of pewter, which have a bluish tint. ... An alloy is a homogeneous hybrid of two or more elements, at least one of which is a metal, and where the resulting material has metallic properties. ... See also: List of elements by atomic number In chemistry and physics, the atomic number (also known as the proton number) is the number of protons found in the nucleus of an atom. ... In nuclear chemistry, the term stable element has been variously defined by different people at different times. ... General Name, Symbol, Number bismuth, Bi, 83 Chemical series poor metals Group, Period, Block 15, 6, p Appearance lustrous pink Standard atomic weight 208. ... This article is about the element. ... A neurotoxin is a toxin that acts specifically on nerve cells – neurons – usually by interacting with membrane proteins such as ion channels. ...

Contents

Notable characteristics

Lead has a dull luster and is a dense, ductile, very soft, highly malleable, bluish-white metal that has poor electrical conductivity. This true metal is highly resistant to corrosion, and because 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. It is a common misconception that lead has a zero Thomson effect. All lead, except 204Pb, is the end product of a complex radioactive decay (see isotopes of lead below). Lead is also poisonous. Image File history File links This is a lossless scalable vector image. ... For other uses, see Density (disambiguation). ... Ductility is the physical property of being capable of sustaining large plastic deformations without fracture (in metals, such as being drawn into a wire). ... Not to be confused with electrical conductance, a measure of an objects or circuits ability to conduct an electric current between two points, which is dependent on the electrical conductivity and the geometric dimensions of the conducting object. ... For the hazard, see corrosive. ... R-phrases S-phrases , , , Flash point Non-flammable Related Compounds Related strong acids Selenic acid Hydrochloric acid Nitric acid Related compounds Hydrogen sulfide Sulfurous acid Peroxymonosulfuric acid Sulfur trioxide Oleum Supplementary data page Structure and properties n, εr, etc. ... This article is about the element. ... The Peltier–Seebeck effect, or thermoelectric effect, is the direct conversion of heat differentials to electric voltage and vice versa. ... Lead poisoning is a medical condition, also known as saturnism, plumbism or painters colic, caused by increased blood lead levels. ...


History

Lead has been commonly used for thousands of years because it is widespread, easy to extract and easy to work with. It is highly malleable and ductile as well as easy to smelt. In the early Bronze Age, lead was used with antimony and arsenic. Lead was mentioned in the Book of Exodus (15:10). In alchemy, lead was thought to be the oldest metal and was associated with the planet Saturn. Lead pipes that bear the insignia of Roman emperors are still in service and many Roman "pigs" (ingots) of lead figure in Derbyshire lead mining history and in the history of the industry in other English centres. The Romans also used lead in molten form to secure iron pins that held together large limestone blocks in certain monumental buildings. Lead's symbol Pb is an abbreviation of its Latin name plumbum for soft metals; originally it was plumbum nigrum, where plumbum candidum was tin. The English word "plumbing" also derives from this Latin root. Image File history File links This is a lossless scalable vector image. ... Electric phosphate smelting furnace in a TVA chemical plant (1942) Chemical reduction, or smelting, is a form of extractive metallurgy. ... The Bronze Age is a period in a civilizations development when the most advanced metalworking has developed the techniques of smelting copper from natural outcroppings and alloys it to cast bronze. ... This article is about the element. ... General Name, Symbol, Number arsenic, As, 33 Chemical series metalloids Group, Period, Block 15, 4, p Appearance metallic gray Standard atomic weight 74. ... This article is about the second book in the Torah. ... For other uses, see Alchemy (disambiguation). ... This article is about the planet. ... The tone or style of this article or section may not be appropriate for Wikipedia. ... For other uses, see Limestone (disambiguation). ... For other uses, see Latin (disambiguation). ... This article is about the metallic chemical element. ...


Lead also refers collectively to the organic and inorganic compounds of lead, which are toxic. Lead poisoning was documented in ancient Rome, Greece, and China. In the 20th century, the use of lead in paint pigments was sharply reduced because of the danger of lead poisoning, especially to children.[1][2][3] By the mid-1980s, a significant shift in lead end-use patterns had taken place. Much of this shift was a result of the U.S. lead consumers' compliance with environmental regulations that significantly reduced or eliminated the use of lead in non-battery products, including gasoline, paints, solders, and water systems. Lead use is being further curtailed by the European Union's RoHS directive. Lead may still be found in harmful quantities in stoneware, vinyl (such as that used for tubing and the insulation of electrical cords), and brass manufactured in China. Around 2006-2007, many children's toys made in China had been recalled due to lead in paint used to color the product. Lead poisoning is a medical condition, also known as saturnism, plumbism or painters colic, caused by increased blood lead levels. ... Natural Ultramarine pigment in powdered form. ... Petrol redirects here. ... The Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment (RoHS) 2002/95/EC [1] (commonly referred to as the Restriction of Hazardous Substances Directive) was adopted in February 2003 by the European Union. ...


Occurrence

Metallic lead does occur in nature, but it is rare. Lead is usually found in ore with zinc, silver and (most abundantly) copper, and is extracted together with these metals. The main lead mineral is galena (PbS), which contains 86.6% lead. Other common varieties are cerussite (PbCO3) and anglesite (PbSO4). General Name, symbol, number zinc, Zn, 30 Chemical series transition metals Group, period, block 12, 4, d Appearance bluish pale gray Standard atomic weight 65. ... This article is about the chemical element. ... For other uses, see Copper (disambiguation). ... For other uses, see Mineral (disambiguation). ... For other uses, see Galena (disambiguation). ... Sample of cerussite-bearing quartzite Cerussite (also known as lead carbonate or white lead ore) is a mineral consisting of lead carbonate (PbCO3), and an important ore of lead. ... Anglesite specimen in its orthorhombic crystalline form Anglesite is a lead sulfate mineral, PbSO4. ...


Lead mining in Wales

Lead ore (galena) is found commonly in northeast Wales. The Northeast Wales Orefield was by far the most important source of lead and zinc in Wales and second in national importance only to the North Pennine Orefield. Lead mining dates back to at least Roman times and continued until well into the 20th century. Galena is present in steeply dipping fissure veins and in pipes and is in Mississippi Valley-type lead-zinc-fluorite and copper-dolomite associations. The mineralisation occurs in the upper parts of the Loggerheads and Cefn Mawr Formations of the Carboniferous Limestone.[4] Carbonate-hosted lead-zinc ore deposits are important and highly valuable concentrations of lead and zinc sulfide ores hosted within carbonate (limestone, marl, dolomite) formations and which share a common genetic origin. ...


Processing of metal from ore

Lead ore
Lead ore

The principal ores of lead are galena (PbS), anglesite (PbSO4) and cerussite (PbCO3). Most ores contain less than 10% lead, and ores containing as little as 3% lead can be economically exploited. Ores are crushed and concentrated by froth flotation typically to 70% or more. Sulfide ores are roasted, producing primarily lead oxide and a mixture of sulfates and silicates of lead and other metals contained in the ore.[5] Lead ore Source: US Government File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Lead ore Source: US Government File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... For other uses, see Galena (disambiguation). ... Anglesite specimen in its orthorhombic crystalline form Anglesite is a lead sulfate mineral, PbSO4. ... Sample of cerussite-bearing quartzite Cerussite (also known as lead carbonate or white lead ore) is a mineral consisting of lead carbonate (PbCO3), and an important ore of lead. ... Froth Flotation is a selective process for separating minerals from gangue by using surfactants and wetting agents. ... Formally, sulfide is the dianion, S2−, which exists in strongly alkaline aqueous solutions formed from H2S or alkali metal salts such as Li2S, Na2S, and K2S. Sulfide is exceptionally basic and, with a pKa > 14, it does not exist in appreciable concentrations even in highly alkaline water. ... Roasting is a metallurgical process in which sulfide ores are converted to oxides, prior to smelting. ... Sulfate is the IUPAC name for the SO42- ion, consisting of a central sulfur atom single bonded to four tetrahedrally oriented oxygen atoms. ... In chemistry, a silicate is a compound consisting of silicon and oxygen (SixOy), one or more metals, and possibly hydrogen. ...


Lead oxide from the roasting process is reduced in a coke-fired blast furnace.[6] This converts most of the lead to its metallic form. Three additional layers separate in the process and float to the top of the metallic lead. These are slag (silicates containing 1.5% lead), matte (sulfides containing 15% lead), and speiss (arsenides of iron and copper). These wastes contain concentrations of copper, zinc, cadmium, and bismuth that can be recovered economically, as can their content of unreduced lead.[5] Slag is also an early play by David Hare. ... This article or section does not cite its references or sources. ... Speiss is a molten phase consisting primarily of iron arsenide that is commonly encountered in lead smelting operations. ...


Metallic lead that results from the roasting and blast furnace processes still contains significant contaminants of arsenic, antimony, bismuth, zinc, copper, silver, and gold. The melt is treated in a reverberatory furnace with air, steam, and sulfur, which oxidizes the contaminants except silver, gold, and bismuth. The oxidized contaminants are removed by drossing, where they float to the top and are skimmed off.[5][7] A reverbatory furnace is a metallurgical or process furnace which characteristically isolates the material being processed from contact with the fuel, but not from contact with the combustion gases. ... Dross is a mass of solid impurities floating on a molten metal bath. ...


Most lead ores contain significant concentrations of silver, resulting in the smelted metal also containing silver as a contaminant. Metallic silver as well as gold is removed and recovered economically by means of the Parkes process.[8][5][7] This article is about the chemical element. ... The Parkes process is a pyrometallurgical industrial process for removing silver from lead, during the production of bullion. ...


Desilvered lead is freed of bismuth according to the Betterton-Kroll process by treating it with metallic calcium and magnesium, which forms a bismuth dross that can be skimmed off.[5][7] The Betterton-Kroll process is an industrial process for removing bismuth from lead. ...


Very pure lead can be obtained by processing smelted lead electolytically by means of the Betts process. The process uses anodes of impure lead and cathodes of pure lead in an electrolyte of silica fluoride.[5][7] The Betts electrolytic process is an industrial process for separating lead and bismuth. ...


Production and Recycling

Worldwide production and consumption of lead is increasing. Total annual production is about 8 million tonnes; about half is produced from recycled scrap. The main countries are Australia, China and the US, which account for more than half of primary production. The most common lead ore is galena or lead sulfide.[9]

  • Annual Metal Production (2006): 7918 Thousand tonnes[10]
  • Annual Mine Production (2006): 3442 Thousand tonnes (lead content)

At current use rates, the supply of lead is estimated to run out in 42 years.[11] Environmental analyst, Lester Brown, however, has suggested lead could run out within 18 years based on a reasonable extrapolation of 2% growth per year.[12] Lester R. Brown is an environmental analyst who has written several books on global environmental issues. ...


Isotopes

Main article: Isotopes of lead

Lead has four stable isotopes - 204Pb, 206Pb, 207Pb, 208Pb and one common radiogenic isotope 202Pb with a half-life of ~53,000 years. Image File history File links This is a lossless scalable vector image. ... Lead (Pb) Standard atomic mass: 207. ... Isotopes are atoms of a chemical element whose nuclei have the same atomic number, Z, but different atomic weights, A. The word isotope, meaning at the same place, comes from the fact that isotopes are located at the same place on the periodic table. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ...


Health effects

Main article: Lead poisoning

Lead is a poisonous metal that can damage nervous connections (especially in young children) and cause blood and brain disorders. Long term exposure to lead or its salts (especially soluble salts or the strong oxidant PbO2) can cause nephropathy, and colic-like abdominal pains. The concern about lead's role in cognitive deficits in children has brought about widespread reduction in its use (lead exposure has been linked to schizophrenia). Most cases of adult elevated blood lead levels are workplace-related.[13] High blood levels are associated with delayed puberty in girls.[14] Lead poisoning is a medical condition, also known as saturnism, plumbism or painters colic, caused by increased blood lead levels. ... Nephropathy refers to damage to or disease of the kidney. ... Colic may refer to: Baby colic – a condition, usually in infants, characterized by incessant crying. ...


Older houses may still contain substantial amounts of lead paint. White lead paint has been withdrawn from sale in industrialized countries, but the yellow lead chromate is still in use; for example, Holland Colours Holcolan Yellow. Old paint should not be stripped by sanding, as this produces inhalable dust. Lead paint is paint containing lead, a heavy metal, that is used as pigment, with Lead(II) chromate (PbCrO4, chrome yellow) and lead(II) carbonate(PbCO3, white lead) being the most common. ... Chrome Yellow is a natural yellow pigment made of lead chromate (PbCrO4). ...


Lead salts used in pottery glazes have on occasion caused poisoning, when acid drinks, such as fruit juices, have leached lead ions out of the glaze.[citation needed] It has been suggested that what was known as "Devon colic" arose from the use of lead-lined presses to extract apple juice in the manufacture of cider. Lead is considered to be particularly harmful for women's ability to reproduce. For that reason, many universities do not hand out lead-containing samples to women for instructional laboratory analyses.[citation needed] Lead acetate (also known as sugar of lead) was used by the Roman Empire as a sweetener for wine, and some consider this to be the cause of the dementia that affected many of the Roman Emperors.[15] A rebuttal to claims that the colic was caused by lead poisoning from cider, written by a cider manufacturer. ... Cider in a pint glass Cider (or cyder) is an alcoholic beverage made primarily from the juices of specially grown varieties of apples. ... Lead acetate (Trihydrate Pb(CH3COO)2·3H2O) is a white crystalline substance made by dissolving lead in acetic acid. ... For other uses, see Roman Empire (disambiguation). ... For other uses, see Dementia (disambiguation). ...


Lead as a soil contaminant is a widespread issue, since lead is present in natural deposits and may also enter soil through (leaded) gasoline leaks from underground storage tanks or through a wastestream of lead paint or lead grindings from certain industrial operations. Excavation of leaking undergound storage tank causing soil contamination Soil contamination is the presence of man-made chemicals or other alteration to the natural soil environment. ... An Underground Storage Tank (UST), in United States environmental law, is a tank and any underground piping connected to the tank that has at least 10 percent of its combined volume underground. ...


Biochemistry of lead poisoning

In medicine, lead inhibits α-aminolevulinate (ALA) dehydratase and ferrochelatase, preventing both porphobilinogen formation and the incorporation of iron into protoporphyrin IX, the final step in heme synthesis. Inhibition of both these steps results in ineffective heme synthesis and subsequent microcytic (hemoglobin-poor) anemia.[citation needed] It has been suggested that this article or section be merged with Ala. ... Porphobilinogen is a pyrrole involved in porphyrin metabolism. ... For other uses, see Iron (disambiguation). ... Protoporphyrins are tetrapyrroles containing the following side chains: methyl (4) propionic acid (2) vinyl (2) In the metabolism of porphyrin, protoporphyrin IX is created by the enzyme protoporphyrinogen oxidase, and the enzyme ferrochelatase converts it into heme. ... Structure of hemoglobin. ... This article discusses the medical condition. ...


Leaching of lead from metal surfaces

The Pourbaix diagram for lead in a non-complexing aqueous medium (eg perchloric acid / sodium hydroxide)
The Pourbaix diagram for lead in a non-complexing aqueous medium (eg perchloric acid / sodium hydroxide)[16]
The Pourbaix diagram for lead in citric acid/citrate
The Pourbaix diagram for lead in citric acid/citrate[16]

It is clear from the Pourbaix diagram below that lead is more likely to corrode in a citrate medium than it is in a non-complexing medium. The central part of the diagram shows that lead metal is more easy to oxidise in the citrate medium than it is in normal water. Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 11 KB, MIME type: image/png) I drew it using Medusa I, the copyright holder of this work, hereby release it into the public domain. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 11 KB, MIME type: image/png) I drew it using Medusa I, the copyright holder of this work, hereby release it into the public domain. ... A Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable (equilibrium) phases of an aqueous electrochemical system. ... Perchloric acid has the formula HClO4 and is a colorless liquid soluble in water. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 13 KB, MIME type: image/png) I, the copyright holder of this work, hereby release it into the public domain. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 13 KB, MIME type: image/png) I, the copyright holder of this work, hereby release it into the public domain. ... A Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable (equilibrium) phases of an aqueous electrochemical system. ... A Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable (equilibrium) phases of an aqueous electrochemical system. ...


In a Pourbaix diagram, the acidity is plotted on the x axis using the pH scale, while how oxidising/reducing nature of the system is plotted on the y axis in terms of volts relative to the standard hydrogen electrode. The diagram shows the form of the element which is most chemically stable at each point, it only comments on thermodynamics and it says nothing about the rate of change (kinetics).
A standard hydrogen electrode (abbreviated SHE) is a redox electrode which is placed in the basis of the thermodynamic scale of oxidation-reduction potentials. ... Thermodynamics (from the Greek θερμη, therme, meaning heat and δυναμις, dynamis, meaning power) is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics. ... Kinetics refers to two different areas of science: Chemical kinetics studies reaction rates. ...


Descriptive chemistry

See also: Category:Lead compounds

Various oxidized forms of lead are easily reduced to the metal. An example is heating PbO with mild organic reducing agents such as glucose. A mixture of the oxide and the sulfide heated together without any reducing agent will also form the metal.[8]

2PbO + PbS   →   3 Pb + SO2

Metallic lead is attacked only superficially by air, forming a thin layer of oxide that protects it from further oxidation. The metal is not attacked by sulfuric or hydrochloric acids. It does, however, dissolve in nitric acid with the evolution of nitric oxide gas to form dissolved Pb(NO3)2. R-phrases S-phrases , , , Flash point Non-flammable Related Compounds Related strong acids Selenic acid Hydrochloric acid Nitric acid Related compounds Hydrogen sulfide Sulfurous acid Peroxymonosulfuric acid Sulfur trioxide Oleum Supplementary data page Structure and properties n, εr, etc. ... R-phrases , S-phrases , , Flash point Non-flammable. ... The chemical compound nitric acid (HNO3), also known as aqua fortis and spirit of nitre, is an aqueous solution of hydrogen nitrate (anhydrous nitric acid). ... R-phrases , , , , S-phrases , , , Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa) Infobox disclaimer and references Nitric oxide or Nitrogen monoxide is a chemical compound with chemical formula NO. This gas is an important signaling molecule in the body of... Lead(II) nitrate is a chemical compound, the inorganic salt of nitric acid and lead. ...

3 Pb + 8 H+ + 8 NO3   →   3 Pb2+ + 6 NO3 + 2 NO + 4H2O

When heated with nitrates of alkali metals, metallic lead oxidizes to form PbO (also known as litharge), leaving the corresponding alkali nitrite. PbO is representative of lead's II oxidation state. It is soluble in nitric and acetic acids, from which solutions it is possible to precipitate halide, sulfate, chromate, carbonate (PbCO3), and basic carbonate (Pb3(OH)2(CO3)2) salts of lead. The sulfide can also be precipitated from acetate solutions. These salts are all poorly soluble in water. Among the halides, the iodide is less soluble than the bromide, which, in turn, is less soluble than the chloride.[17] Trinitrate redirects here. ... Lead(II) oxide or litharge is a yellow oxide of lead of formula PbO, created by heating lead in air. ... Litharge is the natural mineral form of lead(II) oxide, PbO. Litharge is a secondary mineral which forms from the oxidation of galena ores. ... // Definition The nitrite ion is NO2−. A nitrite compound is one that contains this group, either an ionic compound, or an analogous covalent one. ... R-phrases , S-phrases , , , Flash point 43 °C Related Compounds Related carboxylic; acids Formic acid; Propionic acid; Butyric acid Related compounds acetamide; ethyl acetate; acetyl chloride; acetic anhydride; acetonitrile; acetaldehyde; ethanol; thioacetic acid; acetylcholine; acetylcholinesterase Supplementary data page Structure and properties n, εr, etc. ... A halide is a binary compound, of which one part is a halogen atom and the other part is an element or radical that is less electronegative than the halogen, to make a fluoride, chloride, bromide, iodide, or astatide compound. ... Lead (II) sulfate (PbSO4) is a white crystal or powder. ... Chrome Yellow is a natural yellow pigment made of lead chromate (PbCrO4). ... Sample of cerussite-bearing quartzite Cerussite (also known as Horn silver, Lead carbonate, White lead ore) is a mineral consisting of lead carbonate (PbCO3), and an important ore of lead. ... Lead sulfide (British/Commonwealth English sulphide) is a chemical compound PbS, most often purified from the mineral galena. ... Lead acetate (Trihydrate Pb(CH3COO)2·3H2O) is a white crystalline substance made by dissolving lead in acetic acid. ...


The II oxide is also soluble in alkali hydroxide solutions to form the corresponding plumbite salt.[8] The alkali metals are a series of elements comprising Group 1 (IUPAC style) of the periodic table: lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). ... Hydroxide is a polyatomic ion consisting of oxygen and hydrogen: OH− It has a charge of −1. ... The plumbite ion is Pb(OH)3-, or similar. ...

PbO + 2OH + H2O   →   Pb(OH)42–

Chlorination of plumbite solutions causes the formation of lead's IV oxidation state. Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water. ...

Pb(OH)42– + Cl2   →   PbO2 + 2 Cl + 2 H2O

Lead dioxide is representative of the IV state, and is a powerful oxidizing agent. The chloride of this oxidation state is formed only with difficulty and decomposes readily into the II chloride and chlorine gas. The bromide and iodide of IV lead are not known to exist.[17] Lead dioxide dissolves in alkali hydroxide solutions to form the corresponding plumbates.[8] Sample of lead dioxide Lead dioxide, PbO2, also plumbic oxide, lead peroxide, is an oxide of lead, with lead in oxidation state +4. ... European Union Chemical hazard symbol for oxidizing agents Dangerous goods label for oxidizing agents Oxidizing agent placard An oxidizing agent (also called an oxidant or oxidizer) is A chemical compound that readily transfers oxygen atoms or A substance that gains electrons in a redox chemical reaction. ... The plumbate ion is PbO32- or Pb(OH)62-. A plumbate (compound) is a compound containing this ion. ...

PbO2 + 2 OH + 2 H2O   →   Pb(OH)62–

Lead also has an oxide that is a hybrid between the II and IV oxidation states. Red lead (also called minium) is Pb3O4. Red lead, also called minium or lead tetroxide, is a bright red or orange crystalline or amorphous pigment. ...


Lead readily forms an equimolar alloy with sodium metal that reacts with alkyl halides to form organometallic compounds of lead such as tetraethyl lead.[18] For sodium in the diet, see Edible salt. ... In chemistry, an alkyl halide is an organic molecule of the form R_X, where X is a halide and R contains a carbon atom bonded to other functional groups or hydrogens. ... Organometallic have classically been compounds having bonds between one or more metal atoms and one or more carbon atoms of an organyl group. ... Tetra-ethyl lead (also known as TEL, lead tetraethyl and tetraethyllead) is a toxic organometallic chemical compound, with formula (CH2CH3)4Pb, which was once used as a gasoline (petrol) additive. ...


Chloride complexes

Diagram showing the forms of lead in chloride media
Diagram showing the forms of lead in chloride media[16]

Lead(II) forms a series of complexes with chloride, the formation of which alters the corrosion chemistry of the lead. This will tend to limit the solubility of lead in saline media. Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 14 KB, MIME type: image/png) Drawn using medusa I, the copyright holder of this work, hereby release it into the public domain. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 14 KB, MIME type: image/png) Drawn using medusa I, the copyright holder of this work, hereby release it into the public domain. ... The chloride ion is formed when the element chlorine picks up one electron to form an anion (negatively-charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. ... Saline may refer to: Salinity Saline (medicine) Saline, Michigan Saline, Scotland - a village in the burgh of Fife, Scotland. ...

Equilibrium constants for aqueous lead chloride complexes at 25 °C[19]
Pb2+ + Cl → PbCl+      K1 = 12.59
PbCl+ + Cl → PbCl20 K2 = 14.45
PbCl20 + Cl → PbCl3 K3 = 3.98 ×10−1
PbCl3 + Cl → PbCl42− K4 = 8.92 × 10−2



Phase diagrams of solubilities

Plot showing aqueous concentration of dissolved Pb2+ as a function of SO42−
Plot showing aqueous concentration of dissolved Pb2+ as a function of SO42−[16]
Diagram for lead in sulfate media
Diagram for lead in sulfate media[16]

Lead(II) sulfate is poorly soluble, as can be seen in the following diagram showing addition of SO42− to a solution containing 0.1M of Pb2+. The pH of the solution is 4.5, as above that, Pb2+ concentration can never reach 0.1M due to the formation of Pb(OH)2. Observe that Pb2+ solubility drops 10,000 fold as SO42− reaches 0.1M
In physical chemistry and materials science, a phase diagram is a type of graph used to show the equilibrium conditions between the thermodynamically-distinct phases. ... Image File history File links Size of this preview: 800 × 500 pixelsFull resolution (1680 × 1050 pixel, file size: 14 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Size of this preview: 800 × 500 pixelsFull resolution (1680 × 1050 pixel, file size: 14 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 13 KB, MIME type: image/png) Draw using medusa software I, the copyright holder of this work, hereby release it into the public domain. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 13 KB, MIME type: image/png) Draw using medusa software I, the copyright holder of this work, hereby release it into the public domain. ...

Diagram showing the solubility of lead in chloride media. The lead concentrations are plotted as a function of the total chloride present.
Diagram showing the solubility of lead in chloride media. The lead concentrations are plotted as a function of the total chloride present.[16]
Pourbaix diagram for lead in chloride (0.1 M) media
Pourbaix diagram for lead in chloride (0.1 M) media[16]

Here it can be seen that the addition of chloride can lower the solubility of lead, however in chloride rich media (such as aqua regia) the lead can become soluble again as anionic chlorocomplexes. Image File history File links Size of this preview: 800 × 500 pixelsFull resolution (1680 × 1050 pixel, file size: 15 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Size of this preview: 800 × 500 pixelsFull resolution (1680 × 1050 pixel, file size: 15 KB, MIME type: image/png) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 11 KB, MIME type: image/png) Drawn using medusa I, the copyright holder of this work, hereby release it into the public domain. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 11 KB, MIME type: image/png) Drawn using medusa I, the copyright holder of this work, hereby release it into the public domain. ... A Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable (equilibrium) phases of an aqueous electrochemical system. ... Freshly prepared aqua regia is colorless, but it turns orange within seconds. ...


The Pourbaix diagram on the right is for a moderate concentration (0.1 M) of chloride.
A Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable (equilibrium) phases of an aqueous electrochemical system. ...


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 to form glazing bars for stained glass or other multi-lit windows. The practice has become less common, not for danger but for stylistic reasons.
  • 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.[20]
  • Lead or "sheet-lead" is used as a sound deadening layer in such areas as wall, floor and ceiling design in sound studios where levels of airborne and mechanically produced sound are targeted for reduction or virtual elimination.
  • 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.[21]
  • 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 oxide. 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, although this usage is being phased out by some countries to reduce the amount of environmentally unfriendly waste.
  • 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 diver's natural buoyancy and that of his equipment.
  • Lead is often used to balance the wheels of a car; this use is being phased out in favor of other materials for environmental reasons.
  • Lead is still widely used in statues and sculptures.

Image File history File links Wikitext. ... A valve-regulated, sometimes called sealed, lead acid battery Lead-acid batteries, invented in 1859 by French physicist Gaston Planté, are the oldest type of rechargeable battery. ... Composite body, painted, and glazed bottle. ... Strictly speaking, stained glass is glass that has been painted with silver stain and then fired. ... A projectile is any object sent through space by the application of a force. ... Firearms redirects here. ... A sinker is a weight used in fishing to force a lure to sink more rapidly or to increase the distance that it may be cast. ... Lead shielding refers to the use of lead to shield from radiation. ... Radiation hazard symbol. ... A coolant, or heat transfer fluid, is a fluid which flows through a device in order to prevent its overheating, transferring the heat produced by the device to other devices that utilize or dissipate it. ... The Lead-cooled Fast Reactor is a Generation IV reactor that features a fast-spectrum lead or lead/bismuth eutectic liquid metal-cooled reactor with a closed fuel cycle. ... Lead glass is potassium silicate glass which has been impregnated with lead oxide (from 12% to 28% by weight) in its fabrication. ... Lead(II) oxide or litharge is a yellow oxide of lead of formula PbO, created by heating lead in air. ... The choir division of the organ at St. ... This article is about the metallic chemical element. ... Alternative meanings: There is also an Electric-type Pokémon named Electrode. ... In chemistry and manufacturing, electrolysis is a method of separating chemically bonded elements and compounds by passing an electric current through them. ... A solder is a fusible metal alloy, with a melting point or melting range of 180-190°C (360-370 °F), which is melted to join metallic surfaces, especially in the fields of electronics and plumbing, in a process called soldering. ... Ballast is used in sailboats to provide moment to resist the lateral forces on the sail. ... Brazen redirects here. ... A machine tool is a powered mechanical device, typically used to fabricate metal components of machines by machining, which is the selective removal of metal. ... Scuba diving is swimming underwater while using self-contained breathing equipment. ... Divers wear weighting systems, weight belts or weights, generally made of lead, to counteract the buoyancy of other diving equipment, such as diving suits and aluminium diving cylinders. ... Tire weight Tire Balance, also referred to as tire imbalance and tire unbalance, describes the unsymmetrical distribution of mass within an automobile tire and/or the wheel to which it is attached. ...

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 the hot metal used in hot metal typesetting.
  • Lead was used for plumbing in Ancient Rome.
  • Lead was used as a preservative for food and drink in Ancient Rome.
  • Lead was used for joining cast iron water pipes and used as a material for small diameter water pipes until the early 1970s.
  • 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.[22]
  • Lead was used to make bullets for slings.
  • Lead was used as a component of toys. Due to toy safety regulations, this use has been stopped in the United States.
  • Lead was used in car body filler, which was used in many custom cars in the 1940s–60s. Hence the term Leadsled.
  • Lead is a superconductor at 7.2 K and IBM tried to make a Josephson Effect Computer out of lead-alloy.[23]

Contrary to popular belief, pencil "leads" have never been made from lead. The term comes from the Roman stylus, called the penicillus, which was made of lead.[24] When the pencil originated as a wrapped graphite writing tool, the particular type of graphite being used was named plumbago (lit. "act for lead"; "leadmocku"). Lead paint is paint containing lead, a heavy metal, that is used as pigment, with Lead(II) chromate (PbCrO4, chrome yellow) and lead(II) carbonate(PbCO3, white lead) being the most common. ... Chrome Yellow is a natural yellow pigment made of lead chromate (PbCrO4). ... This article or section does not cite any references or sources. ... A plumber wrench for working on pipes and fittings A complex arrangement of rigid steel piping, stop valves regulate flow to various parts of the building. ... Ancient Rome was a civilization that grew from a small agricultural community founded on the Italian Peninsula circa the 9th century BC to a massive empire straddling the Mediterranean Sea. ... Various preserved foods Food preservation is the process of treating and handling food in such a way as to stop or greatly slow down spoilage to prevent foodborne illness while maintaining nutritional value, density, texture and flavor. ... Tetra-ethyl lead (also known as TEL, lead tetraethyl and tetraethyllead) is a toxic organometallic chemical compound, with formula (CH2CH3)4Pb, which was once used as a gasoline (petrol) additive. ... Petrol redirects here. ... Knocking (also called pinking or pinging)— colloquially detonation—in internal combustion engines occurs when air/fuel mixture in the cylinder detonates or ignites prior to the timed pre-set conditions in the engines cylinder(s). ... Occident redirects here. ... Home-made sling. ... A custom 1974 Ford Taunus 2000 GXL. The car has had a roof chop, been shaved of all trim, with vents cut into the rear quarter panels and an all steel body kit moulded into the body. ... A leadsled is a car from the 1950s or early 1960s that has had extensive customization done to the body of it. ... Superconductivity is a phenomenon occurring in certain materials at low temperatures, characterised by the complete absence of electrical resistance and the damping of the interior magnetic field (the Meissner effect. ... The Josephson effect is the phenomenon of current flow across two weakly coupled superconductors, separated by a very thin insulating barrier. ... Ancient Rome was a civilization that grew from a small agricultural community founded on the Italian Peninsula circa the 9th century BC to a massive empire straddling the Mediterranean Sea. ... For other uses, see Graphite (disambiguation). ...


Phrases

A "lead pipe cinch" is something that is absolutely certain. In the 19th century, a horse saddle was safe when it was well "cinched". The "lead pipe" qualifier is an obscure "intensifier".[25] Cinch has multiple meanings: A cinch is a wide strap that attaches a saddle to a horse. ...


A "lead pencil" is a leftover term from when the original pencils were made from the only known deposit of graphite ever to be found in a pure, solid state, in 16th century England. The new material was assumed to be a form of lead. Modern pencils use a marking core made of powdered, refined graphite mixed with clay, as has been the practice for centuries. This article is about the handwriting instrument. ...


See also

Plumbosolvency is the ability of a solvent, notably water, to dissolve lead. ...

References

  1. ^ NSW Multicultural Health Communication Service. NSW Health. Retrieved on 7 April, 2007.
  2. ^ Download: Lead paint: Cautionary note. Queensland Government. Retrieved on 7 April, 2007.
  3. ^ Lead Paint Information. Master Painters, Australia. Retrieved on 7 April, 2007.
  4. ^ Davies, J.R., Wilson, D. & Williamson, I.T. (2004). The geology of the country around Flint. Memoir of the British Geological Survey, Sheet 108. (England and Wales). British Geological Survey, Keyworth.
  5. ^ a b c d e f Samans, Carl H. Engineering Metals and their Alloys MacMillan 1949
  6. ^ Primary Extraction of Lead Technical Notes. LDA International. Retrieved on 7 April, 2007.
  7. ^ a b c d Primary Lead Refining Technical Notes. LDA International. Retrieved on 7 April, 2007.
  8. ^ a b c d Pauling, Linus General Chemistry, W.H. Freeman 1947 ed.
  9. ^ Lead Information. LDA International. Retrieved on 2007-09-05.
  10. ^ Lead Statistics. International Lead and Zinc Study Group. Retrieved on 2007-09-05.
  11. ^ (May 26, 2007) "How Long Will it Last?". New Scientist 194 (2605): 38-39. ISSN 4079 0262 4079.
  12. ^ Brown, Lester (2006). Plan B 2.0: Rescuing a Planet Under Stress and a Civilization in Trouble. New York: W.W. Norton, 109. ISBN 0393328317. 
  13. ^ NIOSH ABLES. United States National Institute for Occupational Safety and Health. Retrieved on 2007-10-04.
  14. ^ Endocrine Disruptors and Abnormalities of Pubertal Development, Schoeters G, et al. Basic & Clinical Pharmacology & Toxicology, 102, 168–175, 2008
  15. ^ The Pernicious Allure of Lead. New York Times.
  16. ^ a b c d e f g Ignasi Puigdomenech, Hydra/Medusa Chemical Equilibrium Database and Plotting Software (2004) KTH Royal Institute of Technology, freely downloadable software at [1]
  17. ^ a b Brady, James E. and Holum, John R. Descriptive Chemistry of the Elements John Wiley and Sons
  18. ^ Merck Index of Chemicals and Drugs, 9th ed., monograph 8393
  19. ^ Ward, C.H.; Hlousek, Douglas A.; Phillips, Thomas A.; Lowe, Donald F. (2000). Remediation of Firing Range Impact Berms. CRC Press. ISBN 1566704626. 
  20. ^ Dr. Rooney, Corinne. Contamination at Shooting Ranges (PDF). The Lead Group, incorporated. Retrieved on 7 April, 2007.
  21. ^ Randerson, James (June 2002). "Candle pollution". NewScientist.com (2348). Retrieved on 2007-04-07.
  22. ^ Countries where Leaded Petrol is Possibly Still Sold for Road Use, as of 22nd February 2007. The Lead Group, incorporated. Retrieved on 7 April, 2007.
  23. ^ Henkels, W. H.; Geppert, L. M.; Kadlec, J.; Epperlein, P. W.; Beha, H. (September 1985). Josephson 4 K-bit cache memory design for a prototype signal processor.. Harvard University. Retrieved on 7 April, 2007.
  24. ^ A history of pencils. www.pencils.com. Retrieved on 7 April, 2007.
  25. ^ Quinion, Michael. lead pipe cinch. World Wide Words. Retrieved on 2007-02-19.

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 248th day of the year (249th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 248th day of the year (249th in leap years) in the Gregorian calendar. ... is the 146th day of the year (147th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... ISSN, or International Standard Serial Number, is the unique eight-digit number applied to a periodical publication including electronic serials. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 277th day of the year (278th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... April 7 is the 97th day of the year in the Gregorian calendar (98th in leap years). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... [[Media:Italic text]]{| style=float:right; |- | |- | |} is the 50th day of the year in the Gregorian calendar. ...

Further reading

  • Keisch, B., Feller, R. L., Levine, A. S., and Edwards, R. R.: "Dating and Authenticating Works of Art by Measurement of Natural Alpha Emitters". In: Science, 155, No. 3767, p. 1238–1242, 1967.
  • Keisch, B: "Dating Works of Art Through their Natural Radioactivity: Improvements and Applications". In: Science, 160, p. 413–415, 1968.
  • Keisch, B: "Discriminating Radioactivity Measurements of Lead: New Tool for Authentication". In: Curator, 11, No. 1., p. 41–52, 1968.

External links

Wikimedia Commons has media related to:
Lead
Look up lead, plumbum in Wiktionary, the free dictionary.
  • Case Studies in Environmental Medicine - Lead Toxicity
  • ToxFAQs™: Lead
  • National Pollutant Inventory - Lead and compounds fact sheet
  • WebElements.com - Lead
  • The Lead Education and Abatement Design Group (Australia)
  • International Lead & Zinc Study Group
  • International Lead Management Center
  • Lead Development Association International
  • Do lead fishing sinkers threaten the environment? (from The Straight Dope)
  • A Small Dose of Toxicology:Lead. A Small Dose Of.... Retrieved on 7 April, 2007.
  • Lead. Los Alamos National Laboratory. Retrieved on 7 April, 2007.
  • NIST's X-Ray Mass Attenuation Coefficients - Lead. NIST. Retrieved on 7 April, 2007.
  • Jennifer B. McKim, Keith Sharon and William Heisel. "Scandal involving lead-laced Mexican candy being eaten by children in California", Orange Counter Register, 25-04-2004. Retrieved on 2007-04-07. 
  • Darshak Sanghavi, "Getting the Lead Out: If only it was as easy as recalling the Mattel toys", Slate magazine, August 21, 2007
  • National Institute for Occupational Safety and Health - ABLES Page

Image File history File links Commons-logo. ... Wikipedia does not have an article with this exact name. ... Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 151 languages. ... Cecil Adams is the pen name of the author of The Straight Dope since 1973, a popular question and answer column published in The Chicago Reader, syndicated in thirty newspapers in the United States and Canada, and available online. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... April 7 is the 97th day of the year in the Gregorian calendar (98th in leap years). ...


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Lead is a particularly dangerous chemical, as it can accumulate in individual organisms, but also in entire food chains.
Lead Poisoning - NSC (2958 words)
The lead produced by vehicle emissions continues even today to present a hazard, as much of that lead now remains in soil where it was deposited over the years, especially near well-traveled roads and highways.
In other words, if a woman had been exposed to enough lead as a child for some of the lead to have been stored in her bones, the mere fact of pregnancy can trigger the release of that lead and can cause the fetus to be exposed.
Exposure to lead is estimated by measuring levels of lead in the blood (in micrograms of lead per deciliter of blood).
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