| Discovery date | Ancient |
| Discovered by | - |
| Origin of the name | The name comes from the Anglo-Saxon word for the metal, 'lead' |
| Allotropes |
|
Pb
Lead
82
207.2
| Group | 14 | Melting point | 327.462°C, 621.432°F, 600.612 K |
| Period | 6 | Boiling point | 1749°C, 3180°F, 2022 K |
| Block | p | Density (g cm−3) | 11.3 |
| Atomic number | 82 | Relative atomic mass | 207.2 |
| State at 20°C | Solid | Key isotopes | 208Pb |
| Electron configuration | [Xe] 4f145d106s26p2 | CAS number | 7439-92-1 |
| ChemSpider ID | 4509317 | ChemSpider is a free chemical structure database | |
Image explanation
Lead has been known to, and used by, humans for many centuries. This long history is reflected in the image by the use of an early alchemical symbol for lead and carved Ancient Roman characters.
Appearance
A dull, silvery-grey metal. It is soft and easily worked into sheets.
Uses
This easily worked and corrosion-resistant metal has been used for pipes, pewter and paint since Roman times. It has also been used in lead glazes for pottery and, in this century, insecticides, hair dyes and as an anti-knocking additive for petrol. All these uses have now been banned, replaced or discouraged as lead is known to be detrimental to health, particularly that of children.
Lead is still widely used for car batteries, pigments, ammunition, cable sheathing, weights for lifting, weight belts for diving, lead crystal glass, radiation protection and in some solders.
It is often used to store corrosive liquids. It is also sometimes used in architecture, for roofing and in stained glass windows.
Biological role
Lead has no known biological role. It can accumulate in the body and cause serious health problems. It is toxic, teratogenic (disturbs the development of an embryo or foetus) and carcinogenic.
Daily intake of lead from all sources is about 0.1 milligrams. The average human body stores about 120 milligrams of lead in the bones.
Natural abundance
Lead is chiefly obtained from the mineral galena by a roasting process. At least 40% of lead in the UK is recycled from secondary sources such as scrap batteries and pipes.
Lead has been mined for more than 6,000 years, and the metal and its compounds have been used throughout history. Small lead nuggets have been found in pre-Columbian Peru, Yucatan, and Guatemala.
The Greeks mined lead on a large scale from 650 onwards and not only knew how to obtain the metal but how to covert this to white lead. Because of its superb covering power, this was the basis of paints for more than 2000 years, until the middle of the last century.
The Romans employed lead on a large scale, mining it mainly in Spain and Britain, and using it also for water pipes, coffins, pewter tableware, and to debase their silver coinage. While its mining declined in the Dark Ages it reappeared in Medieval times and found new uses, such as pottery glazes, bullets, and printing type. In the last century it was a fuel additive.
| Atomic radius, non-bonded (Å) | 2.02 | Covalent radius (Å) | 1.45 |
| Electron affinity (kJ mol−1) | 35.121 |
Electronegativity (Pauling scale) |
1.8 |
|
Ionisation energies (kJ mol−1) |
1st
715.596
2nd
1450.414
3rd
3081.481
4th
4083.26
5th
6638.2
6th
-
7th
-
8th
-
|
||
| Common oxidation states | 4, 2 | ||||
| Isotopes | Isotope | Atomic mass | Natural abundance (%) | Half life | Mode of decay |
| 204Pb | 203.973 | 1.4 | - | - | |
| 206Pb | 205.974 | 24.1 | - | - | |
| 207Pb | 206.976 | 22.1 | - | - | |
| 208Pb | 207.977 | 52.4 | > 2 x 1019 y | sf | |
|
|
|
Specific heat capacity (J kg−1 K−1) |
130 | Young's modulus (GPa) | 16.1 | |||||||||||
| Shear modulus (GPa) | 5.59 | Bulk modulus (GPa) | 45.8 | |||||||||||
| Vapour pressure | ||||||||||||||
| Temperature (K) |
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| Pressure (Pa) |
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| Listen to Lead Podcast |
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Transcript :
Chemistry in its element: lead (Promo) You're listening to Chemistry in its element brought to you by Chemistry World, the magazine of the Royal Society of Chemistry. (End promo) Chris Smith Hello, this week we're sinking to new depths as we meet the metal that spawned the plumb line, a rock group, plumbing and even poisoning, not to mention a generation of alchemists who tried in vain to turn this substance into gold. It is of course lead, and here to swing it for us is science writer Phil Ball. Phil Ball Lead is the Eeyore of metals - slow, dull and heavy. In its Latin form, plumbum, it enters our vocabulary by virtue of its soft and ponderous character: we once plumbed depths with a suspended grey blob of the stuff, emphatically commanded by gravity, while plumbers have long since traded their malleable lead pipes for plastic. Everything associated with lead tends towards over-burdened gloom: in the ancient scheme of metal symbolism, lead was linked to Saturn, the melancholy planet, personified by the old god also called Cronos who castrated his father and swallowed his children. Even the spark of glamour the metal gets from association with the world's greatest rock band stems from the Eeyorish prediction that they would sink like a lead balloon or zeppelin. Yes, lead is the original heavy metal, the most notorious offender in that toxic group. Lead damages the brain and the kidneys, it can cause anaemia and a form of gout with the doleful title of saturnine gout. Even the Romans knew about lead poisoning - the doctor Cornelius Celsus warned about the bad effects of lead white, used in paint and cosmetics, while the engineer Vitruvius recommended earthenware pipes over lead ones. Yet we were slow to learn. Lead white, a form of lead carbonate, remained the artist's best white pigment right up until the nineteenth century, when it was replaced by zinc white. As paint manufacture became industrialized, lead white spread sickness and death among factory workers: a report in the Transactions of the Royal Society in the seventeenth century listed vertigo, dizziness, blindness, stupidity and paralytic affections among the conditions it caused. And as late as in 2007 the toy manufacturer Mattel was forced to recall millions of toys made in China that had been coloured with lead paint. Meanwhile, a toxic trickle of lead from solder and the electrodes of batteries leaches slowly from landfill sites throughout the world. In 2006 the European Union effectively banned lead from most consumer electronics, but it remains in use elsewhere. To alchemists, lead was the lowliest of metals - in a sense, it was where all metals started. In talk of base metals, which alchemy tried to turn to silver and gold, there was none so base as lead. The alchemists believed that lead slowly matured into other metals in the ground. But alchemy also offered lead a chance to shake off its grey and graceless image. It does not take much to draw splendid colours out of lead. The ancient technologists blanched the dull metal by placing lead strips in pots with vinegar, and shutting them away in a shed full of animal dung. The vinegar fumes and gas from fermenting dung conspired to corrode lead into lead white. Heat this gently, and it turns yellow: a form of lead oxide known as litharge or, in the Middle Ages, massicot. Heat it some more, and it goes bright red, as you form a different kind of oxide. Both of these substances were used by artists - red lead was, for a long time, their finest red, used for painting many a bright robe in the Middle Ages. It was the signature colour of Saint Jerome. To the alchemists, those colour changes weren't just a way to make pigments. They signified some more profound alteration taking place in the metal, bringing it close to the colour of gold. It's no wonder, then, that their experiments often began with lead. They came no closer to making real gold, but they started to explore the processes of chemical transformation. Lead, however, seems habituated to revealing its true and dirty colours. Exposed to air, it may go on taking up oxygen until it turns black. Red lead has become chocolate brown on paintings throughout the world, from Japan to India to Switzerland. In urban galleries there is another danger, as the sulfurous fumes of pollution react with red lead to from black lead sulphide. There seems to be no getting away from it: lead has a glum and melancholy heart. Chris Smith Phil Ball plumbing the depths of the scientific story of lead. The next edition of Chemistry in its element promises to be a record breaker. Mark Peplow You can learn a lot about someone by meeting their family and the same is true for the element. That's how we come to know so much about astatine. Often trumpeted as the rarest naturally occurring element in the world, it's been estimated that the top kilometre of the earth's crust contains less than 50 mg of astatine making it Guinness world record's rarest element. Chris Smith And you can hear Mark Peplow telling the tale of the world's rarest chemical in next week's Chemistry in its element. I'm Chris Smith, thank you for listening, see you next time. (Promo) Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by thenakedscientists.com. There's more information and other episodes of Chemistry in its element on our website at chemistryworld.org/elements. (End promo)
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Visual Elements images and videos
© Murray Robertson 1998-2017.
W. M. Haynes, ed., CRC Handbook of Chemistry and Physics, CRC Press/Taylor and Francis, Boca Raton, FL, 95th Edition, Internet Version 2015, accessed December 2014.
Tables of Physical & Chemical Constants, Kaye & Laby Online, 16th edition, 1995. Version 1.0 (2005), accessed December 2014.
J. S. Coursey, D. J. Schwab, J. J. Tsai, and R. A. Dragoset, Atomic Weights and Isotopic Compositions (version 4.1), 2015, National Institute of Standards and Technology, Gaithersburg, MD, accessed November 2016.
T. L. Cottrell, The Strengths of Chemical Bonds, Butterworth, London, 1954.
John Emsley, Nature’s Building Blocks: An A-Z Guide to the Elements, Oxford University Press, New York, 2nd Edition, 2011.
Thomas Jefferson National Accelerator Facility - Office of Science Education, It’s Elemental - The Periodic Table of Elements, accessed December 2014.
Periodic Table of Videos, accessed December 2014.
Derived in part from material provided by the British Geological Survey © NERC.
Elements 1-112, 114, 116 and 117 © John Emsley 2012. Elements 113, 115, 117 and 118 © Royal Society of Chemistry 2017.
Produced by The Naked Scientists.
Created by video journalist Brady Haran working with chemists at The University of Nottingham.
© Murray Robertson 1998-2017.
Data
W. M. Haynes, ed., CRC Handbook of Chemistry and Physics, CRC Press/Taylor and Francis, Boca Raton, FL, 95th Edition, Internet Version 2015, accessed December 2014.
Tables of Physical & Chemical Constants, Kaye & Laby Online, 16th edition, 1995. Version 1.0 (2005), accessed December 2014.
J. S. Coursey, D. J. Schwab, J. J. Tsai, and R. A. Dragoset, Atomic Weights and Isotopic Compositions (version 4.1), 2015, National Institute of Standards and Technology, Gaithersburg, MD, accessed November 2016.
T. L. Cottrell, The Strengths of Chemical Bonds, Butterworth, London, 1954.
Uses and properties
John Emsley, Nature’s Building Blocks: An A-Z Guide to the Elements, Oxford University Press, New York, 2nd Edition, 2011.
Thomas Jefferson National Accelerator Facility - Office of Science Education, It’s Elemental - The Periodic Table of Elements, accessed December 2014.
Periodic Table of Videos, accessed December 2014.
Supply risk data
Derived in part from material provided by the British Geological Survey © NERC.
History text
Elements 1-112, 114, 116 and 117 © John Emsley 2012. Elements 113, 115, 117 and 118 © Royal Society of Chemistry 2017.
Podcasts
Produced by The Naked Scientists.
Periodic Table of Videos
Created by video journalist Brady Haran working with chemists at The University of Nottingham.
