82 thallium ← lead → bismuth Sn ↑ Pb ↓ Uuq periodic table
General
Name, Symbol, Number	lead, Pb, 82
Chemical series	poor metals
Group, Period, Block	14, 6, p
Appearance	bluish white
Atomic mass	207.2(1) g/mol
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/cm³
Liquid density at m.p.	10.66 g/cm³
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
Heat of vaporization	179.5 kJ/mol
Heat capacity	(25 °C) 26.650 J/(mol·K)
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
	2nd: 1450.5 kJ/mol
	3rd: 3081.5 kJ/mol
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 nΩ·m
Thermal conductivity	(300 K) 35.3 W/(m·K)
Thermal expansion	(25 °C) 28.9 µm/(m·K)
Speed of sound (thin rod)	(r.t.) (annealed) 1190 m/s
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
Notable isotopes
Main article: Isotopes of lead iso NA half-life DM DE (MeV) DP 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 3.792 206Hg Beta 0.064 210Bi
References

Lead is a chemical element in the periodic table that has the symbol Pb (L. 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, and is part of solder, pewter, and fusible alloys. Lead has the highest atomic number of all stable elements. (But see the article on Bismuth, which has a half life so long it can be considered stable.) General Name, Symbol, Number Thallium, Tl, 81 Chemical series Poor metals Group, Period, Block 13 (IIIA), 6, p Density, Hardness 11. ... General Name, Symbol, Number Bismuth, Bi, 83 Chemical series Poor metals Group, Period, Block 15 (VA), 6, p Density, Hardness 9. ... General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ... Known properties Name, Symbol, Number Ununquadium, Uuq, 114 Chemical series Presumably poor metals Group, Period, Block 14, 7, p Appearance Unknown, probably a metallic and silvery white or grey colour Atomic weight [289] amu Supposed half-life 30 seconds Electron configuration [Rn] 5f14 6d10 7s27p2 (a guess based upon radon... File links The following pages link to this file: Lead Template:Lead infobox User:Femto/elements e7 Categories: GFDL images ... State at standard temperature and pressure those numbered in red are gases those numbered in green are liquids those numbered in black are solid Natural occurrence those without borders have not been discovered/synthesized yet those with dotted borders do not occur naturally (Synthetic elements) those with dashed borders naturally... This is a list of the chemical elements, sorted by name. ... Categories: Chemical elements ... A chemical series is a group of chemical elements whose physical and chemical characteristics vary progressively from one end of the series to another. ... The poor metals or post-transition metals are the metallic elements of the p-block, occurring between the metalloids and the transition metals, shown belown in red. ... A periodic table group is a vertical column in the periodic table of the chemical elements. ... In the periodic table of the elements, a period is a 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. ... Lead sample. ... ... To help compare different orders of magnitude we list here masses between 60. ... Electron atomic and molecular orbitals In atomic physics, the electron configuration is the arrangement of electrons in an atom, molecule or other body. ... General Name, Symbol, Number xenon, Xe, 54 Chemical series noble gases Group, Period, Block 18, 5, p Appearance colorless Atomic mass 131. ... Properties The electron is a subatomic particle. ... In physics and quantum chemistry, an energy level is a quantized energy of a bound quantum mechanical state. ... 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. ... A solid is a state of matter, characterized by a definite volume and a definite shape (i. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... Room temperature, in laboratory reports, is taken to be roughly 21–23 degrees Celsius (70–73 degrees Fahrenheit), or 294–296 kelvins. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... The degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius (1701–1744), who first proposed a similar system in 1742. ... Fahrenheit is a temperature scale named after the German physicist Gabriel Fahrenheit (1686–1736), who proposed it in 1724. ... The boiling point of a substance is the temperature at which it can change state from a liquid to a gas throughout the bulk of the liquid. ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... The degree Celsius (°C) is a unit of temperature named after the Swedish astronomer Anders Celsius (1701–1744), who first proposed a similar system in 1742. ... Fahrenheit is a temperature scale named after the German physicist Gabriel Fahrenheit (1686–1736), who proposed it in 1724. ... This article is in need of attention. ... 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. ... The heat of vaporization is a physical property of substances. ... 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. ... Heat capacity (abbreviated Cth or just C, also called thermal capacity) is the ability of matter to store heat. ... The vapor pressure is the pressure (if the vapor is mixed with other gases, the partial pressure) of a vapor. ... Rose des Sables (Sand Rose), a formation of gypse crystal In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... The oxidation state or oxidation number is defined as the sum of negative and positive charges in an atom, which indirectly indicates the number of electrons it has accepted or donated. ... In chemistry, an amphoteric substance is one that can react with either an acid or base (more generally, the word describes something made of, or acting like, two components). ... Electronegativity is the measure of the ability of an atom or molecule to attract electrons in the context of a chemical bond. ... Electronegativity is a measure of the attraction that an atom has for the bonding pair of electrons in a covalent bond. ... ... 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. ... The poopie is the distance from the atomic nucleus to the outmost stable electron orbital in a atom that is at equilibrium. ... To help compare different orders of magnitude this page lists lengths between 100 pm and 1 nm (10-10 m and 10-9 m). ... Picometre (American spelling: picometer) is an SI measure of length that is equal to 10−12 of a metre. ... The poopie is the distance from the atomic nucleus to the outmost stable electron orbital in a atom that is at equilibrium. ... To help compare different orders of magnitude this page lists lengths between 100 pm and 1 nm (10-10 m and 10-9 m). ... Picometre (American spelling: picometer) is an SI measure of length that is equal to 10−12 of a metre. ... Covalent radius in chemistry corresponds to half of the distance between two identical atomic nuclei, bound by a covalent bond. ... To help compare different orders of magnitude this page lists lengths between 100 pm and 1 nm (10-10 m and 10-9 m). ... Picometre (American spelling: picometer) is an SI measure of length that is equal to 10−12 of a metre. ... The title given to this article is incorrect due to technical limitations. ... To help compare different orders of magnitude this page lists lengths between 100 pm and 1 nm (10-10 m and 10-9 m). ... Picometre (American spelling: picometer) is an SI measure of length that is equal to 10−12 of a metre. ... In physics, magnetism is a phenomenon by which materials exert an attractive or repulsive force on other materials. ... Diamagnetism is a very weak form of magnetism that is only exhibited in the presence of an external 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. ... It is the quantity of heat, Q, transmitted through a unit thickness, L, in a direction normal to a surface of unit area, A, due to a unit temperature gradient, ΔT, under steady state conditions and when the heat transfer is dependent only on the temperature gradient. ... In physics, thermal conductivity, λ, is the quantity of heat transmitted, due to unit temperature gradient, in unit time under steady conditions in a direction normal to a surface of unit area, when the heat transfer is dependent only on the temperature gradient thermal conductivity = heat flow rate / (distance × temperature... The coefficient of thermal expansion is used in two ways: as a volumetric thermal expansion coefficient as a linear thermal expansion coefficient These characteristics are closely related. ... The speed of sound c (from Latin celeritas, velocity) varies depending on the medium through which the sound waves pass. ... Room temperature, in laboratory reports, is taken to be roughly 21–23 degrees Celsius (70–73 degrees Fahrenheit), or 294–296 kelvins. ... 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 (also known as the modulus of elasticity or elastic modulus) is a measure of the stiffness of a given material. ... In materials science, shear modulus S, sometimes referred to as the modulus of rigidity, is defined as the ratio of shear stress to the shear strain: S = shear stress/shear strain = (F/A)/Φ. Another commonly accepted symbol is G. Shear modulus is usually measured in ksi (kips per square... The bulk modulus K of a fluid or solid is the inverse of the compressibility: where p is pressure and V is volume. ... When a sample of material is stretched in one direction, it tends to get thinner in the other two directions. ... Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ... 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. ... Isotopes are forms of a chemical element whose nuclei have the same atomic number, Z, but different atomic masses, A. The word isotope, meaning at the same place, comes from the fact that all isotopes of an element are located at the same place on the periodic table. ... 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. ... An electronvolt (symbol: eV) is the amount of energy gained by a single unbound electron when it falls through an electrostatic potential difference of one volt. ... 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 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. ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery white Atomic mass 200. ... A Synthetic radioisotope is a radioisotope that is not found in nature no matter by what mechanism it is formed. ... A year 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 chemical elements that will occur when there are too many protons in the nucleus of an atom, and there isnt enough energy to emit a positron. ... General Name, Symbol, Number Thallium, Tl, 81 Chemical series Poor metals Group, Period, Block 13 (IIIA), 6, p Density, Hardness 11. ... Different isotopes of one chemical element may have different radioactive properties. ... Properties In physics, the neutron is a subatomic particle with no net electric charge and a mass of 939. ... Different isotopes of one chemical element may have different radioactive properties. ... Properties In physics, the neutron is a subatomic particle with no net electric charge and a mass of 939. ... Different isotopes of one chemical element may have different radioactive properties. ... Properties In physics, the neutron is a subatomic particle with no net electric charge and a mass of 939. ... A Synthetic radioisotope is a radioisotope that is not found in nature no matter by what mechanism it is formed. ... A year 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. ... General Name, Symbol, Number mercury, Hg, 80 Chemical series transition metals Group, Period, Block 12, 6, d Appearance silvery white Atomic mass 200. ... 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 (VA), 6, p Density, Hardness 9. ... Recommended values for many properties of the elements, together with various references, are collected on these data pages. ... A chemical element, often called simply element, is a substance that cannot be divided or changed into different substances by ordinary chemical methods. ... The periodic table of the chemical elements, also called the Mendeleev periodic table, is a tabular display of the known chemical elements. ... Latin was the language originally spoken in the region around Rome called Latium. ... The atomic number (Z) is a term used in chemistry and physics to represent 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. ... For a list of biologically injurious substances, including toxins and other materials, as well as their effects, see poison. ... The poor metals or post-transition metals are the metallic elements of the p-block, occurring between the metalloids and the transition metals, shown belown in red. ... Most lead-acid storage batteries have six cells. ... 0. ... A solder is a fusible metal alloy (often of tin and lead), with a melting point or melting range below 450°C (840°F) and is melted to join metallic surfaces, especially in the fields of electronics and plumbing, in a process called soldering. ... Pewter is a metal alloy, traditionally between 85 and 96 percent tin, and the rest copper and/or lead. ... An alloy is a combination, either in solution or compound, of two or more elements, at least one of which is a metal, and where the resultant material has metallic properties. ... General Name, Symbol, Number Bismuth, Bi, 83 Chemical series Poor metals Group, Period, Block 15 (VA), 6, p Density, Hardness 9. ...

Notable characteristics

Lead has a bright 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. 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. Lead is the only metal in which there is zero Thomson effect. Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... Ductility is the physical property of being capable of sustaining large plastic deformations without fracture (in metals, such as being drawn into a wire). ... Electrical conductivity is a measure of how well a material accommodates the transport of electric charge. ... Corrosion Corrosion is deterioration of useful properties in a material due to reactions with its environment. ... Sulfuric acid (British English: sulphuric acid), H2SO4, is a strong mineral acid. ... General Name, Symbol, Number antimony, Sb, 51 Series metalloids Group, Period, Block 15 (VA), 5, p Density, Hardness 6697 kg/m3, 3 Appearance silvery lustrous grey Atomic properties Atomic weight 121. ... The Peltier-Seebeck effect, or thermoelectric effect, is the direct conversion of heat differentials to electric voltage and vice versa. ...

Applications

• Lead is a major constituent of the Lead-acid battery, used as car batteries.
• Lead was used as a white pigment in Lead paint.
• Lead was used for plumbing in Ancient Rome, and lead sticks were used as pencils (for the last 450 years they've been made with graphite).
• Because of its density, fishing sinkers are made from lead, as are projectiles for shotguns, handguns, and rifles.
• 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. [1]
• Lead is used as shielding from radiation.
• Lead glass is comprised of 12-28% lead. It changes the optical characteristics of the glass and reduces the transmission of radiation.
• Tetraethyl lead has been used in leaded fuels to reduce engine knocking. Due to health concerns, this is no longer common practice in the Western World.

Most lead-acid storage batteries have six cells. ... Lead paint is paint containing lead, which was used until the 1970s as a white pigment. ... Plumbing, from the Latin for lead (plumbum), is the trade of working with pipes for water, drainage and natural gas. ... Ancient Rome was a civilization that existed in Europe, North Africa, and the Middle East between 753 BC and its downfall in AD 476. ... A pencil is a handheld instrument used to write and draw, usually on paper. ... Graphite (named by Abraham Gottlob Werner in 1789, from the Greek γραφειν: to draw/write, for its use in pencils) is one of the allotropes of carbon. ... A sinker is a weight used in fishing to force a lure to sink more rapidly. ... A projectile is any object sent through the air by the application of some force. ... Radiation generally means the transmission of waves, objects or information from a source into a surrounding medium or destination. ... Lead glass is potassium silicate glass which has been impregnated with a small amount of lead oxide (from 12% to 28% by weight) in its fabrication. ... 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. ... Gasoline, as it is known in North America, or petrol, in many Commonwealth countries (sometimes also called motor spirit) is a petroleum-derived liquid mixture consisting primarily of hydrocarbons, used as fuel in internal combustion engines. ... Knocking (also called pinking or pinging)—technically detonation—in internal combustion engines occurs when fuel in the cylinder is ignited by the firing of the spark plug and smooth burning proceeds but some of the unburned mixture in the combustion chamber explodes before the flame front can reach it, combusting... The term Western world can have multiple meanings depending on its context. ...

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 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. Lead's symbol Pb is an abbreviation of its Latin name plumbum. The English word "plumbing" also derives from this Latin root. For other uses of the name, see Exodus (disambiguation) Exodus is the second book of the Torah (the five books of Moses) and also the Tanakh (the Hebrew Bible) and Christian Old Testament. ... Alchemy is an early protoscientific practice combining elements of chemistry, physics, astrology, art, semiotics, metallurgy, medicine, mysticism, and religion. ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... This article details some of the history of lead mining in Derbyshire. ... Latin is the language originally spoken in the region around Rome called Latium. ...

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 nonbattery products, including gasoline, paints, solders, and water systems. Gasoline, as it is known in North America, or petrol, in many Commonwealth countries (sometimes also called motor spirit) is a petroleum-derived liquid mixture consisting primarily of hydrocarbons, used as fuel in internal combustion engines. ...

Occurrence

Lead ore

Native lead does occur in nature, but it is rare. Currently 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). But more than half of the lead used currently comes from recycling. 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. ... General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ... This article is about minerals in the geologic sense; for nutrient minerals see dietary mineral; for the band see Mineral (band). ... Galena is a lead ore. ... 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. ... Anglesite specimen in its orthorhombic crystalline form Anglesite is a lead sulfate mineral, PbSO4. ...

In mining, the ore is extracted by drilling or blasting and then crushed and ground. The ore is then treated using extractive metallurgy. The Froth flotation process separates the lead and other minerals from the waste rock (tailings) to form a concentrate. The concentrate, which can range from 50% to 60% lead, is dried and then treated using pyrometallurgy. The concentrate is sintered before being smelted in to produce a 97% lead concentrate. The lead is then cooled in stages which causes the lighter impurites (dross) to rise to the surface where they can be removed. The molten lead bullion is then refined by additional smelting with air being passed over the lead to form a slag layer containing any remaining impurities and producing 99.9% pure lead. Extractive metallurgy is the practice of extracting metal from ore, purifying it, and recycling it. ... Froth Flotation is a selective process for separating minerals from gangue by using surfactants and wetting agents. ... Tailings are the rejected material from mining and screening operations. ... Pyrometallurgy uses high temperatures to transform metals and their ores. ... Sintering is a method for making objects from powder, increasing the adhesion between particles as they are heated. ...

Isotopes

Lead has four stable, naturally occurring isotopes: Pb-204 (1.4%), Pb-206 (24.1%), Pb-207 (22.1%) and Pb-208 (52.4%). Pb-206, Pb-207 and Pb-208 are all radiogenic, and are the end products of complex decay chains that begin at U-238, U-235 and Th-232 respectively. The corresponding half-lives of these decay schemes vary markedly: 4.47 × 10⁹, 7.04 × 10⁸ and 1.4 × 10¹⁰ years, respectively. Each is reported relative to ²⁰⁴Pb, the only non-radiogenic stable isotope. The ranges of isotopic ratios for most natural materials are 14.0-30.0 for Pb-206/Pb-204, 15.0-17.0 for Pb-207/Pb-204 and 35.0-50.0 for Pb-208/Pb-204, although numerous examples outside these ranges are reported in the literature. Isotopes are forms of a chemical element whose nuclei have the same atomic number, Z, but different atomic masses, A. The word isotope, meaning at the same place, comes from the fact that all isotopes of an element are located at the same place on the periodic table. ... A radiogenic nuclide is one that is produced by a process of radioactive decay. ... Nearly all the decay products of radioactive decay are themselves radioactive. ... General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block ?, 7, f Appearance silvery gray metallic Atomic mass 238. ... General Name, Symbol, Number thorium, Th, 90 Chemical series transition metals Group, Period, Block ?, 7, f Appearance silvery white Atomic mass 232. ... 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. ... Scientific notation is a convenient way to write very large and very small numbers. ...

Precautions

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 historical use of lead acetate (also known as sugar of lead) by the Roman Empire as a sweetener for wine is considered by some to be the cause of the dementia which affected many of the Roman Emperors. The skull and crossbones symbol traditionally used to label a poisonous substance. ... 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. ... The Roman Empire is the term conventionally used to describe the Ancient Roman polity in the centuries following its reorganization under the leadership of Octavian (better known as Caesar Augustus). ... Dementia (from Latin demens) is progressive decline in cognitive function due to damage or disease in the brain beyond what might be expected from normal aging. ... Roman Emperor is the title historians use to refer to rulers of the Roman Empire, after the epoch conventionally named the Roman Republic. ...

Health effects

Main article: lead poisoning Lead poisoning is a condition, also known as plumbism or painters colic, caused by increased levels of blood serum lead levels. ...

The concern about lead's role in mental retardation in children has brought about widespread reduction in its use (lead exposure has been linked to schizophrenia). Paint containing lead has been withdrawn from sale in industralised countries, though many older houses may still contain substantial lead in their old paint: it is generally recommended that old paint should not be stripped by sanding, as this generates inhalable dust.

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. 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. Species Malus domestica Malus sieversii Apple is the fruit (pome) of the genus Malus belonging to the family Rosaceae, and is one of the most widely cultivated tree fruits. ... Cider (also spelled: cyder) refers to a beverage containing the juice of apples. ...

The earliest pencils actually used lead, though 'pencil leads' have been made for the last couple of centuries from graphite, a naturally occurring form (allotrope) of carbon. A pencil is a handheld instrument used to write and draw, usually on paper. ... Pencil lead is the marking substance inside a pencil or mechanical pencil. ... Graphite (named by Abraham Gottlob Werner in 1789, from the Greek γραφειν: to draw/write, for its use in pencils) is one of the allotropes of carbon. ... Allotropy (Gr. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ...

Language derivations

The Latin plumbum has given birth to a number of terms in the English language:

• Plumbing, or system of piping, derives from the fact that pipes were once made of lead.
• Plumb bob or plummet, a small, pointed body of metal the weight of which is used to draw a string vertical under tension, refers to the fact that they were originally made from lead.
• Plumb wall is so-said because a plumb bob is used to find the vertical.
• Plumbing the depths derives from the use of the lead weight to draw the sounding line down to the bottom of the water body (or to the end of the line if the water's really deep!).
• Plumb crazy may derive from the fact that lead poisoning can cause insanity; or, according to the Oxford English Dictionary, from a U.S. sense of plum (derived from plumb) meaning 'completely'.
• Plumbism is the medical term for lead poisoning.
• Aplomb comes from the French à plomb, meaning plumb vertical, and therefore confident and cool.

The plum, however, does not get its name from this root. Rather, plum is derived from the Old English word plume. The Oxford English Dictionary (OED) is a comprehensive dictionary published by the Oxford University Press (OUP). ... Genera Several, including: Prunus domestica Prunus insititia Prunus maritima Prunus salicina A plum is a stone-fruit tree in the genus Prunus. ... Note: This page contains phonetic information presented in the International Phonetic Alphabet (IPA) using Unicode. ...

References

• Los Alamos National Laboratory - Lead

External links

• Case Studies in Environmental Medicine - Lead Toxicity
• WebElements.com - Lead
• EnvironmentalChemistry.com - Lead
• Do lead fishing sinkers threaten the environment? (from The Straight Dope)

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. ...

Literature

• 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 Trough 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.