Sulfur is a chemical element with the atomic number 16 in the periodic table. It’s the 5th most abundant element in Earth’s crust with an approximate concentration of 0.06 percent. Being a member of the oxygen group of the periodic table, this non-metallic chalcogen element has six valence electrons (3s²3p⁴) and can form compounds with almost any other chemical substance.
Element 16 is essential for all life forms. This vitally important non-metallic trace mineral participates in some of the most important processes in the human body. It supports the formation of amino acids, protein synthesis, as well as the metabolism of cells. Since it’s one of the key components of our hair and skin, it’s often referred to as ‘the beauty mineral’.
Chemical and Physical Properties of Sulfur
|Symbol of Sulfur||S|
|Group of Sulfur||Non-Metal|
|Crystal Structure of Sulfur||Orthorhombic|
|Atomic weight (mass)||32.066|
|Shells of Sulfur||2,8,6|
|Orbitals of Sulfur||[Ne] 3s2 3p4|
|Valence of Sulfur||2,4,6|
|Physical state||Solid non-metallic crystalline substance at room temperature|
|Half-life||From less than 200 nanoseconds to 170 minutes|
|Electronegativity according to Pauling||2.58|
|Van der Waals radius||0.127 nm|
|Ionic radius||0.184 (-2) nm; 0.029 (+6)|
|Covalent Radius of Sulfur||1.02 Å|
|Atomic Radius of Sulfur||1.09 Å|
|Atomic Volume of Sulfur||15.5 cm³/mol|
|Name Origin of Sulfur||Latin: sulphur (brimstone)|
|Discovered By||Known to the ancients|
|Pronounced of Sulfur||SUL-fer|
|Oxydation States of Sulfur||±2,4,(6)|
|Uses of Sulfur||Used in matches, gunpowder, medicines, rubber and pesticides, dyes and insecticides. Also for making sulfuric acid (H2SO4)|
|Description of Sulfur||Greenish-yellow, disagreeable gas. Never found in free form in nature|
With the periodic table symbol S, atomic number 16, atomic mass of 32.06 g.mol-1, and electron configuration [Ne]3s23p4, sulfur is a soft, brittle, odorless, and tasteless non-metal substance. It reaches its boiling point at 444.61°C, 832.3°F, 717.76 K, while the melting point is achieved at 115.21°C, 239.38°F, 388.36 K. This member of the oxygen family of elements has an electronegativity of 2.5 according to Pauling, whereas the atomic radius according to van der Waals is 0.127 nm.
Sulfur occurs in five allotropes: α-S (orthorhombic), β-S (monoclinic), S2, S3, and cyclo-S8 form.
How Was Sulfur Discovered?
The first instances of sulfur’s existence have been noted in the Bible where this chemical is referred to as brimstone. Namely, a reference cited in the Bible (“Fire and brimstone”) suggests that element 16 and its properties were familiar to ancient civilizations.
Archeological explorations have derived evidence dating from the period of around 500 BCE in China, where sulfur was used in explosives. The Byzantine Greeks have also referred to a substance labeled as a ‘Greek fire’. They used this chemical compound prepared with sulfur, charcoal, pitch, and naphtha in warfare.
After centuries of sulfur’s exploitation by the earliest civilizations, the great French chemist Antoine Lavoisier (1743 – 1794) became the first scientist to recognize the chemical properties of this chalcogen and include it in his list of chemical elements.
The wide range of applications and the availability of this chemical element in nature brought about a “Sulphur Crisis”, and made sulfur a reason for a war conflict between the Kingdom of the Two Sicilies and the United Kingdom during the 19th century.
How Did Sulfur Get Its Name?
The origin of the name of this chemical element can be related to several sources – either from the Sanskrit word ‘sulvere/shulbari’ with the meaning of ‘enemy (ari) of copper (shulba)’, Arabic ‘sufra’ meaning ‘yellow’, or the Latin word ‘sulphurium/sulpur‘. In Greek, sulfur is referred to as ‘Θειο’. In addition, the Nature Chemistry Journal explains the reasons behind the different spellings of sulphur/sulfur.
Where Can You Find Sulfur?
Element 16 is widely distributed in nature. In the Universe, sulfur occurs as the tenth most abundant chemical element. It was formed by the alpha process occurring in massive stars. High levels of this bright-yellow chemical with a crystalline structure have been also detected on the Sun’s surface. Sulfuric acid aerosol droplets are also traced in the atmosphere of the planet Venus.
On Earth, sulfur is easily found near regions with high volcanic activity and near hot springs. In nature, sulfur commonly occurs in minerals and ores, especially in the sulfide and sulfate minerals, such as:
- Pyrite (iron sulfide);
- Cinnabar (mercury sulfide);
- Galena (lead sulfide);
- Sphalerite / Zinc blende (zinc sulfide);
- Stibnite (antimony sulfide);
- Gypsum (calcium sulfate);
- Alunite (potassium aluminum sulfate);
- Barite (barium sulfate);
- Epsom salts (magnesium sulfate).
Since sulfur participates in the structure of amino acids, it can be found in all living organisms, seawater, as well as in all bodily tissues.
A large number of sulfur and sulfite compounds also occur in coal ores, natural gases (fossil fuels), petroleum, most often in the form of barium sulfate and calcium sulfate dihydrate. It’s mainly isolated from the ores and minerals by the Frasch Process. During this process, the deposits are first melted by heated water, after which sulfur can be extracted in the water residue of the reaction.
Furthermore, sulfur can be obtained as a byproduct of oil extraction and refinement of the refinement of fossil fuels into usable energy sources (like gasoline), or after the processing of various metals (ex. nickel, copper, zinc, cadmium, lead). The isolated sulfur can be derived in the form of flowers of sulfur, a fine crystalline powder, or as roll sulfur (cast cakes or sticks).
Owned to the fact that this chemical element is one of the most widespread ones in nature, sulfur deposits can be located in a wide number of countries, such as Japan, Germany, Poland, Chile, Indonesia, Canada, and China. In the United States, the swamplands in Louisiana and the salt domes in the Gulf of Mexico are the locations richest in naturally occurring sulfur. The oil from tar sands in Alberta, Canada, for instance, contains 20 percent sulfur. Nowadays, most of the commercially used sulfur comes from the Middle East and Central Asia.
Sulfur in Everyday Life
This highly abundant element has a wide palette of applications in many industries. Sulphuric acid (H2SO4) is one of the most important industrial derivatives of sulfur. Its practical use can be observed from the following instances:
- The chemical industry utilizes sulfur in the manufacturing processes of fine chemicals, solvents, concrete, matches, fertilizers, insecticides, fungicides, paper, detergents, pigments, etc. It’s typically used as an electrolyte, cleaning agent, and a catalyst in the chemical processes;
- The pharmaceutical company produces a wide range of supplements, medications, and shampoos aimed at the treatment of dandruff, mouth ulcers, sores, and even osteoporosis;
- Dimethyl sulfide is a colorless sulfur compound often used in fuels and food additives;
- SO2 is used as a bleaching agent. It can remove the oxygen from a substance containing O2 molecules which makes the colored item look colorless;
- Element 16 and its compounds have a practical application in the production of explosives, petroleum products, sheet metal, manufacturing of esters, inorganic salts,
- The antioxidant and antibacterial properties are used in the wine-making process. Added to wine, SO2 maintains the fresh taste of the wine for a longer time;
- The inorganic white chemical compound labeled as zinc sulfide is often used as an X-ray cathode, in infrared optics, and glow sticks.
Sulfur and Health
Element 16 (S) is an essential trace element for all life forms. After calcium and phosphorus, sulfur is the third most abundant mineral in the human body. It supports the formation of amino acids, which are building blocks of the central nervous system, skeletal muscles, and cardiovascular system.
As key components of coenzymes, enzymes, and hormones, the sulfur-containing amino acids (taurine, cysteine, methionine, and homocysteine) participate in the formation and function of almost every tissue of the body by supporting the metabolic processes of the cells.
It also supports the health of our nails, hair, and cartilages. Namely, the long chains of the protein labeled as keratin (in hair and nails) are linked together with sulfur. The reshaping of these sulfur atoms also reshapes our hair into curly or straight.
What Is Sulfur Deficiency?
When there aren’t sufficient quantities of this trace mineral in the body to support the aforementioned vital processes, sulfur deficiency occurs. The lack of sulfur obstructs the production of glutathione, an antioxidant that prevents cellular damage. Also, when the absorbed levels of sulfur in our body are low, joint pain may occur since this mineral is a key component of the connective tissues in the human body.
While we don’t commonly consider the amount of sulfur that we intake via food, this mineral can be found in foods that are often found in our everyday diet, such as in:
- Bean sprouts;
- Green beans;
In a form of capsules or powders, sulfur supplements are prescribed to elevate the level of this trace element in the human body. Supplemental sulfur may aid muscle soreness, alleviate osteoarthritis, as well as protect against allergies. Dimethyl sulfoxide (DMSO) and methylsulfonylmethane (MSM) are the most common supplemental forms of sulfur.
Important: Please note that this sulfur fact sheet is for educational and informative purposes only. This list is not complete and many other drugs may interact with sulfur, including prescription and over-the-counter medicines, proton pump inhibitor (PPI) drugs, vitamins, and herbal products. We strongly advise that you seek medical advice from a qualified healthcare provider or trained health professionals before treating any medical problems or adding sulfur supplements to your diet.
How Dangerous Is Sulfur?
Sulfur dioxide (SO2) is one of the most toxic atmospheric gasses. Shortly after the inhalation of sulfur dioxide from the air, the affected individual experiences problems with breathing, coughing, dizziness, headache, and chest tightness. The prolonged exposure to the toxicity of SO2 may result in severe lung damage, pulmonary edema, corneal haze, or heart failure.
Environmental Effects of Sulfur
Sulfur dioxide (SO2) is one of the biggest atmospheric pollutants. This sulfur compound is a toxic gas that contributes to the global warming of our planet. Released naturally by volcanic activity in nature, human activities (such as burning of fossil fuels, coal, smelters, and the fossil fuels combustion at power plants) are the main sources of SO2 emissions in our environment.
When the sulfur dioxide dissolves in the clouds, it makes the precipitation more acidic than normal. Acid rain is formed when sulfur dioxide (SO2) and nitrogen oxides (NOx) create chemical reactions with H2O, O2, or other components of the atmosphere. Acidic precipitations are exceptionally harmful to the aquatic ecosystem of our planet, as well as for all life forms.
Isotopes of Sulfur
There are 23 isotopes of sulfur with atomic mass ranging from 27S to 39S. Among them, four forms of this chemical element have a stable atomic structure: S-32, S-33, S-34, and S-36. All of the radioactive forms of sulfur are short-lived, apart from the 32S isotope, which has a half-life of 87 days.
|Z||N||Isotopic mass (Da)
[n 2][n 3]
[n 6][n 7]
|Natural abundance (mole fraction)|
|Excitation energy||Normal proportion||Range of variation|
|27S[n 8]||16||11||27.01828(43)#||15.5(15) ms||β+ (96.6%)||27P||(5/2+)|
|β+, p (2.3%)||26Si|
|β+, 2p (1.1%)||25Al|
|28S||16||12||28.00437(17)||125(10) ms||β+ (79.3%)||28P||0+|
|β+, p (20.7%)||27Si|
|29S||16||13||28.99661(5)||188(4) ms||β+ (53.6%)||29P||5/2+#|
|β+, p (46.4%)||28Si|
|35S||16||19||34.96903232(4)||87.37(4) d||β−||35Cl||3/2+||Trace[n 10]|
|41S||16||25||40.979593(4)||1.99(5) s||β− (>99.9%)||41Cl||7/2−#|
|β−, n (<.1%)||40Cl|
|42S||16||26||41.981065(3)||1.016(15) s||β− (>96%)||42Cl||0+|
|β−, n (<4%)||41Cl|
|43S||16||27||42.986908(5)||265(13) ms||β− (60%)||43Cl||3/2−#|
|β−, n (40%)||42Cl|
|44S||16||28||43.990119(6)||100(1) ms||β− (81.7%)||44Cl||0+|
|β−, n (18.2%)||43Cl|
|45S||16||29||44.99572(111)||68(2) ms||β−, n (54%)||44Cl||3/2−#|
List of Sulfur Compounds
Sulfur compounds are very common in both nature and the Universe. They participate in various vital processes of life, as well as in the planetary processes. When sulfur becomes a part of a compound, it adopts the oxidation state of -2 to +6.
Elemental sulfur can form both organosulfur compounds and inorganic sulfur compounds, as well as sulfur oxoacids, sulfur enzymes, sulfur oxides, metabisulfites, tetrathionates, thiocyanates, thiometallates, thionyl compounds, thiosulfates, acid amide derivatives, acid halides, etc.
The list of most common sulfur compounds includes the following items:
- Allyl propyl disulfide
- Asparagusic acid
- Copper monosulfide
- Disulfur dibromide
- Disulfur dichloride
- Disulfur difluoride
- Glionitrin A
- Glutathione disulfide
- Hydrogen disulfide
- Iridium disulfide
- Tropodithietic acid
- Dithionic acid
- Sodium dithionate
- Chloro(dimethyl sulfide)gold(I)
- Carbon disulfide
- Carbon subsulfide
- Carbonyl sulfide
- Thionyl bromide
- Thionyl chloride
- Rieske protein
- Rubredoxin A
5 Interesting Facts and Explanations
- The only elements sulfur cannot form a chemical reaction with are: gold, platinum, iridium, tellurium, and noble gases.
- The characteristic odor released by sulfur dioxide resembles burning matches.
- Despite its bad reputation as a toxic gas, sulfur dioxide is used as a food preservative typically used with dried fruits, beer, wine, soft drinks, tin coconut milk, etc. Its function is to preserve the color of the food and the drinks longer.
- The sulfur-rich volcanoes appear to have blue-colored lava.
- While pure sulfur is odorless, the characteristic bad smell of rotten eggs associated with the sulfur compounds (almost always felt near natural hot springs) is a result of the hydrogen sulfide gas (H2S) and other organosulfur compounds. Another fun fact regarding the bad smell of this substance is that sulfur compounds called mercaptans give skunks their defensive odor.