| Discovery date | approx 2100BC |
| Discovered by | - |
| Origin of the name | The name comes from the Anglo-Saxon 'tin' |
| Allotropes | White Sn, Gray Sn, Rhombic Sn |
Sn
Tin
50
118.710
| Group | 14 | Melting point | 231.928°C, 449.47°F, 505.078 K |
| Period | 5 | Boiling point | 2586°C, 4687°F, 2859 K |
| Block | p | Density (g cm−3) | 7.287 |
| Atomic number | 50 | Relative atomic mass | 118.710 |
| State at 20°C | Solid | Key isotopes | 120Sn |
| Electron configuration | [Kr] 4d105s25p2 | CAS number | 7440-31-5 |
| ChemSpider ID | 4509318 | ChemSpider is a free chemical structure database | |
Image explanation
A common alchemical symbol for tin is shown here embossed on a ‘tin’ can. Tin cans are traditionally made from steel coated with tin.
Appearance
A soft, pliable metal. Below 13°C it slowly changes to a powder form.
Uses
Tin has many uses. It takes a high polish and is used to coat other metals to prevent corrosion, such as in tin cans, which are made of tin-coated steel. Alloys of tin are important, such as soft solder, pewter, bronze and phosphor bronze. A niobium-tin alloy is used for superconducting magnets.
Most window glass is made by floating molten glass on molten tin to produce a flat surface. Tin salts sprayed onto glass are used to produce electrically conductive coatings.
The most important tin salt used is tin(II) chloride, which is used as a reducing agent and as a mordant for dyeing calico and silk. Tin(IV) oxide is used for ceramics and gas sensors. Zinc stannate (Zn2SnO4) is a fire-retardant used in plastics.
Some tin compounds have been used as anti-fouling paint for ships and boats, to prevent barnacles. However, even at low levels these compounds are deadly to marine life, especially oysters. Its use has now been banned in most countries.
Biological role
Tin has no known biological role in humans, although it may be essential to some species. The metal is non-toxic, but organo-tin compounds can be poisonous and must be handled with care. Plants easily absorb tin.
Natural abundance
Tin is found principally in the ore cassiterite (tin(IV) oxide). It is mainly found in the ‘tin belt’ stretching through China, Thailand and Indonesia. It is also mined in Peru, Bolivia and Brazil. It is obtained commercially by reducing the ore with coal in a furnace.
Tin had a direct impact on human history mainly on account of bronze, although it could be used in its own right, witness a tin ring and pilgrim bottle found in an Egyptian tomb of the eighteenth dynasty (1580–1350 BC). The Chinese were mining tin around 700 BC in the province of Yunnan. Pure tin has also been found at Machu Picchu, the mountain citadel of the Incas.
When copper was alloyed with around 5 per cent of tin it produced bronze, which not only melted at a lower temperature, so making it easier to work, but produced a metal that was much harder, and ideal for tools and weapons. The Bronze Age is now a recognised stage in the development of civilisation. How bronze was discovered we do not know, but the peoples of Egypt, Mesopotamia, and the Indus valley started using it around 3000 BC.
| Atomic radius, non-bonded (Å) | 2.17 | Covalent radius (Å) | 1.40 |
| Electron affinity (kJ mol−1) | 107.298 |
Electronegativity (Pauling scale) |
1.96 |
|
Ionisation energies (kJ mol−1) |
1st
708.581
2nd
1411.793
3rd
2943.054
4th
3930.332
5th
6973.96
6th
-
7th
-
8th
-
|
||
| Common oxidation states | 4, 2 | ||||
| Isotopes | Isotope | Atomic mass | Natural abundance (%) | Half life | Mode of decay |
| 112Sn | 111.905 | 0.97 | - | - | |
| 114Sn | 113.903 | 0.66 | - | - | |
| 115Sn | 114.903 | 0.34 | - | - | |
| 116Sn | 115.902 | 14.54 | - | - | |
| 117Sn | 116.903 | 7.68 | - | - | |
| 118Sn | 117.902 | 24.22 | - | - | |
| 119Sn | 118.903 | 8.59 | - | - | |
| 120Sn | 119.902 | 32.58 | - | - | |
| 122Sn | 121.903 | 4.63 | - | - | |
| 124Sn | 123.905 | 5.79 | > 2.2 x 1018 y | β-β- | |
|
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|
Specific heat capacity (J kg−1 K−1) |
227 | Young's modulus (GPa) | 49.9 | |||||||||||
| Shear modulus (GPa) | 18.4 | Bulk modulus (GPa) | 58.2 | |||||||||||
| Vapour pressure | ||||||||||||||
| Temperature (K) |
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| Pressure (Pa) |
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| Listen to Tin Podcast |
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Transcript :
Chemistry in its element: tin (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 the element that changed the course of industry and also gave birth to the Bronze Age. We find out why the Romans came to Britain and why your organ can go out of tune in winter perhaps irreversibly. But tin fans should watch out because much of what we call tin isn't. Katherine Holt Tin cans, tin foil, tin whistles, tin soldiers.....these are that things that come to mind when we think of tin. Which is unfortunate, as tin cans are actually made from steel; tin foil is made from aluminium and tin whistles....well you get the idea. To be associated with a list of obsolete consumable items is especially unfortunate for tin, when we consider that it was responsible for literally changing civilisation! Have you heard of the Bronze Age? Well, some enterprising metal workers at the end of the Stone Age discovered that the addition of a small amount of tin into molten copper resulted in a new alloy. It was harder than copper but also much easier to shape, mould and sharpen. This discovery was so revolutionary that that Bronze Age was born - a name given to any civilisation which made tools and weapons from this alloy of copper and tin. So important was tin that the secrets of its trade were closely guarded. The ancient Greeks spoke of the 'Cassiterides ' or 'Tin Islands' which were believed to lie off the north west coast of Europe. These mysterious islands have never been identified and probably never existed. All the Greeks knew was that tin came to them by sea and from the north-west and so the story arose of the tin islands. It is likely the tin came from northern Spain and from Cornwall. In fact, the strategic importance of the Cornish tin mines is considered one of the reasons why the Roman Empire invaded Britain. Tin may have played another historical role - this time in the defeat of Napolean's army in the Russian campaign of 1812. It has been claimed that in the severe cold the tin buttons on the soldier's uniforms disintegrated into powder, leading to severe loss of life from hypothermia. The accuracy of this story is debatable, but the transformation of tin from a shiny metal into a grey powder at low temperatures is chemical fact. In the cold winters of Northern Europe the loss of tin organ pipes as they began to disintegrate into dust has been known for centuries as 'tin pest', 'tin disease' or 'tin leprosy'. This process is actually a very simple chemical transformation of one structural form of tin - silvery, metallic 'white tin' or 'beta tin' - into another - brittle, non-metallic 'grey tin' or 'alpha tin'. For pure tin the transition occurs at 13.2 oC but the transition temperature is lower, or does not occur at all, if there are enough impurities present, for example if tin is alloyed with another metal. A modern day problem with 'tin pest' has thus arisen, as the tin-lead alloys used to coat leads in electrical equipment have sometimes been replaced with pure tin due to new environmental legislation. In cold temperatures the metallic beta tin coating transforms into non-conducting, brittle alpha tin and falls off the leads. The loose alpha tin powder then moves around inside the equipment, but because it is non-conducting it doesn't cause a problem. However, in warmer temperatures this alpha tin powder transforms back to conducting beta tin, leading to short circuits and all kinds of problems. The way to defeat 'tin pest' is to mix tin with other metals, and these days tin is mainly used to form alloys - for example bronze, pewter and solders. Since tin is the most tonally resonant of all metals it is used in bell metals and to make organ pipes, which are generally a mix of 50:50 tin and lead. The proportion of tin generally determines the pipe's tone. And so we return to the humble tin can. Although not made from tin, cans are often coated with tin on the inside to prevent corrosion. So while it may now seem that tin plays a small role in our everyday lives, remember that once it figured in the rise and fall of civilisations. Chris Smith So it was the tin that lured the Romans to Britain - funny that, there was me thinking it was the wonderful weather. Telling Tin's tale was Katherine Holt from UCL. Next week the substance that makes you see red. Brian Clegg If you are listening to this podcast on a computer with a traditional colour monitor Europium will be enhancing your view of the Chemistry World website. When colour TVs were first developed, the red pixels were relatively weak, which meant the whole colour spectrum had to be kept muted. But a phosphor doped with europium proved a much better, brighter source of red and is still present in most surviving monitors and TVs that predate the flat screen revolution. Chris Smith And you can hear from Brian Clegg how the power of Europium was harnessed in the first place and how it was discovered on next week's Chemistry in its Element, I hope you can join us. Until then, I'm Chris Smith, thank you for listening and goodbye. (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.
