| Discovery date | Prehistoric |
| Discovered by | - |
| Origin of the name | The name is derived either from the Sanskrit 'sulvere', or the Latin 'sulfurium'. |
| Allotropes | α-S (orthorhombic), β-S (monoclinic), S2, S3, cyclo-S8 |
S
Sulfur
16
32.06
| Group | 16 | Melting point | 115.21°C, 239.38°F, 388.36 K |
| Period | 3 | Boiling point | 444.61°C, 832.3°F, 717.76 K |
| Block | p | Density (g cm−3) | 2.07 |
| Atomic number | 16 | Relative atomic mass | 32.06 |
| State at 20°C | Solid | Key isotopes | 32S |
| Electron configuration | [Ne] 3s23p4 | CAS number | 7704-34-9 |
| ChemSpider ID | 4515054 | ChemSpider is a free chemical structure database | |
Image explanation
The alchemical symbol for sulfur is shown against a ‘fire and brimstone’ background.
Appearance
There are several allotropes of sulfur. The most common appears as yellow crystals or powder.
Uses
Sulfur is used in the vulcanisation of black rubber, as a fungicide and in black gunpowder. Most sulfur is, however, used in the production of sulfuric acid, which is perhaps the most important chemical manufactured by western civilisations. The most important of sulfuric acid’s many uses is in the manufacture of phosphoric acid, to make phosphates for fertilisers.
Mercaptans are a family of organosulfur compounds. Some are added to natural gas supplies because of their distinctive smell, so that gas leaks can be detected easily. Others are used in silver polish, and in the production of pesticides and herbicides.
Sulfites are used to bleach paper and as preservatives for many foodstuffs. Many surfactants and detergents are sulfate derivatives. Calcium sulfate (gypsum) is mined on the scale of 100 million tonnes each year for use in cement and plaster.
Biological role
Sulfur is essential to all living things. It is taken up as sulfate from the soil (or seawater) by plants and algae. It is used to make two of the essential amino acids needed to make proteins. It is also needed in some co-enzymes. The average human contains 140 grams and takes in about 1 gram a day, mainly in proteins.
Sulfur and sulfate are non-toxic. However, carbon disulfide, hydrogen sulfide and sulfur dioxide are all toxic. Hydrogen sulfide is particularly dangerous and can cause death by respiratory paralysis.
Sulfur dioxide is produced when coal and unpurified oil are burned. Sulfur dioxide in the atmosphere causes acid rain. This can cause lakes to die, partly by making toxic aluminium salts soluble, so that they are taken up by living things.
Natural abundance
Sulfur occurs naturally as the element, often in volcanic areas. This has traditionally been a major source for human use. It is also widely found in many minerals including iron pyrites, galena, gypsum and Epsom salts.
Elemental sulfur was once commercially recovered from wells by the Frasch process. This involved forcing super-heated steam into the underground deposits to melt the sulfur, so it could be pumped to the surface as a liquid.
Modern sulfur production is almost entirely from the various purification processes used to remove sulfur from natural gas, oil and tar sands. All living things contain sulfur and when fossilised (as in fossil fuels) the sulfur remains present. If unpurified fossil fuels are burnt, sulfur dioxide can enter the atmosphere, leading to acid rain.
Sulfur is mentioned 15 times in the Bible, and was best known for destroying Sodom and Gomorrah. It was also known to the ancient Greeks, and burnt as a fumigant. Sulfur was mined near Mount Etna in Sicily and used for bleaching cloth and preserving wine, both of which involved burning it to form sulfur dioxide, and allowing this to be absorbed by wet clothes or the grape juice. For centuries, sulfur along with mercury and salt, was believed to be a component of all metals and formed the basis of alchemy whereby one metal could be transmuted into another.
Antoine Lavoisier thought that sulfur was an element, but in 1808 Humphry Davy said it contained hydrogen. However, his sample was impure and when Louis-Josef Gay-Lussac and Louis-Jacques Thénard proved it to be an element the following year, Davy eventually agreed.
| Atomic radius, non-bonded (Å) | 1.80 | Covalent radius (Å) | 1.04 |
| Electron affinity (kJ mol−1) | 200.41 |
Electronegativity (Pauling scale) |
2.58 |
|
Ionisation energies (kJ mol−1) |
1st
999.589
2nd
2251.763
3rd
3356.72
4th
4556.231
5th
7004.305
6th
8495.824
7th
27107.363
8th
31719.56
|
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|
| Common oxidation states | 6, 4, 2, -2 | ||||
| Isotopes | Isotope | Atomic mass | Natural abundance (%) | Half life | Mode of decay |
| 32S | 31.972 | 94.99 | - | - | |
| 33S | 32.971 | 0.75 | - | - | |
| 34S | 33.968 | 4.25 | - | - | |
| 36S | 35.967 | 0.01 | - | - | |
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Specific heat capacity (J kg−1 K−1) |
708 | Young's modulus (GPa) | Unknown | |||||||||||
| Shear modulus (GPa) | Unknown | Bulk modulus (GPa) | 7.7 | |||||||||||
| Vapour pressure | ||||||||||||||
| Temperature (K) |
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| Pressure (Pa) |
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| Listen to Sulfur Podcast |
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Transcript :
Chemistry in its element: sulfur (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 stinky sediments, skunks and the smell of hell. Well they all begin with the letter S, and so does this week's element. Here's Steve Mylon. Steve Mylon "How did it smell?" That was the only question I needed to ask a geologist colleague of mine about the sediment she was trying to understand. The smell of the sediment tells a great deal about the underlying chemistry. Thick black anoxic sediments can be accompanied by a putrid smell which is unique to reduced sulfur. Maybe this is why sulfur has such a bad reputation. My son wouldn't eat eggs for 6 months when he got a smell of his first rotten one. In the bible it seems that whenever something bad happens or is about to happen burning sulfur is in the picture: For example, In Genesis we hear, "the lord rained down burning sulfur on Sodom and Gomorrah" And in Revelation we read that the sinners will find their place in a fiery lake of burning sulfur." The odd thing is that in both cases we shouldn't expect anything smelly to be produced. When sulfur burns in air, it generally forms sulfur dioxide or sulfur trioxide, the latter of which lacks any smell [amended from the podcast audio file, which states that sulfur dioxide does not smell]. These compounds can further oxidize and rain out as sulfuric or sulfurous acid. This is the mechanism for acid rain which has reeked havoc on the forests of the northeastern United States as sulfur rich coals are burned to generate electricity in midwestern states and carried east by prevailing winds where sulfuric acid is rained out causing all sorts of ecological problems. Additionally, the combination of burning coal and fog creates smog in many industrial cities causing respiratory problems among the locals. Here too, sulfur dioxide and sulfuric acid are implicated as the culprits. But again, there is no smell associated with this form of sulfur. So if hell or the devil is said have the 'smell of sulfur', maybe that's not so bad. But reduce sulfur by giving it a couple of electrons, and its smell is unmistakable. The requirement of sulfur reduction to sulfide has clearly been lost in translation . Hell that smells like hydrogen sulfide or any number of organic-sulfur compound will not be a nice place at all. The organic sulfide compounds known as thiols or mercaptans smell so bad, that they are commonly added to odorless natural gas in very small quantities in order to serve as a 'smell alarm' should there be leak in a natural gas line. Skunks take advantage of the foul smell of butyl seleno-mercaptan as a means of defending themselves against their enemies. And for me, personally, the worst chemistry of all occurs when reduced sulfur imparts a bad (skunky) taste in bottles of wine or beer. -bound to ruin a nice night out on the town or an afternoon at the local pub. So, where does the "smell of hell" come from in anoxic sediments. Interestingly, some bacteria have evolved to make use of oxidized sulfur , sulfate, as an electron acceptor during respiration. In a similar manner to the way humans reduce elemental oxygen to water, these bacteria reduce sulfate to hydrogen sulfide- They clearly don't mind the smell. Smell is not the only interesting chemistry that accompanies reduced sulfur. The deep black associated with anoxic sediments results from the low solubility of most metal sulfides. Sulfate reduction to sulfide generally accompanies the precipitation of pyrite (iron sulfide), cinnabar (mercury sulfide), galena (lead sulfide) and many more minerals. These metal sulfides have become an important industrial source for many of these important metals. Industry is one place you are almost certain to find sulfur or more importantly sulfuric acid which is used in processes ranging from fertilizer production to oil refining. In fact sulfuric acid ranks as the most highly produced chemical in the industrialized world. Imagine that, the element with such a hellish reputation has become one of the most important. And some even suggest that sulfur could save the planet. The biogenic compound dimethylsulfide (DMS) is produced from the cleavage of dimethylsufonoprioponate, an osmotic regulatory compound produced by plankton in the ocean. The volatility and low solubility of DMS results in some 20 Tg (10^12) of sulfur emitted to the atmosphere annually. DMS is oxidized to SO2 and finally to sulfuric acid particles which can act as cloud condensation nuclei forming clouds which have a net cooling effect to the planet. Imagine warmer temperatures followed by greater biological activity resulting in more DMS to the atmosphere. The resulting cloud formation might work to cool a warming planet. It's almost like the plankton are opening an umbrella made up-in part- of sulfur. From a symbol of damnation to savior...what a turn around!!. Chris Smith Steve Mylon sniffing out the stinky story of Sulfur. Thankfully next week's element is a lot less odiforous. John Emsley The story of its discovery started when Rayleigh found that the nitrogen extracted from the air had a higher density than that made by decomposing ammonia. The difference was small but real. Ramsay wrote to Rayleigh suggesting that he should look for a heavier gas in the nitrogen got from air, while Rayleigh should look for a lighter gas in that from ammonia. Ramsay removed all the nitrogen from his sample by repeatedly passing it over heated magnesium. He was left with one percent which would not react and found it was denser than nitrogen. Its atomic spectrum showed new red and green lines, confirming it a new element. Chris Smith And that new element was Argon nicknamed the lazy element because originally scientists thought that it wouldn't react with anything. Now we know that's not true and John Emsley will be here to unlock Argon secrets on next week's Chemistry in its Element, I hope you can join us. 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.
