Sulfur
Sulfur is a bright yellow nonmetal that's been known since antiquity, referred to in ancient texts as brimstone long before anyone understood chemistry. Unlike most elements, it's often found in nature in pure, elemental form, especially near volcanic vents and hot springs, which is why it required no complex extraction process to discover.
- Group · Period
- 16 · 3
- At room temp
- solid
- Melts at
- 388.36 K
- Density
- 2.067 g/cm³
- Discovered
- Ancient
Uses
Sulfur’s dominant modern use is as the raw material for sulfuric acid, produced in enormous volumes and used throughout industry, most notably in manufacturing phosphate fertilizers, but also in petroleum refining, mineral processing, and countless other chemical reactions. Sulfur is also a key ingredient in vulcanizing rubber, a process that gives tires and other rubber products their durability and elasticity.
Historically and to this day, sulfur is one of the three ingredients in gunpowder, alongside charcoal and saltpeter. It’s also used in the production of certain fungicides and pesticides in agriculture, and sulfur compounds are added to some foods and beverages as preservatives.
History
Sulfur has no single discoverer — it’s one of the few elements found in nature in pure form, occurring as bright yellow deposits around volcanic vents, and it’s been recognized and used since ancient times under the name “brimstone” in religious and historical texts. Because it required no complex extraction, it was familiar to humans long before the concept of a chemical element existed. French chemist Antoine Lavoisier helped establish sulfur as a genuine element, rather than a compound, in the late 1770s, as part of his broader effort to reform and systematize chemistry.
Fun facts
- Sulfur has been known since ancient times as 'brimstone,' referenced in religious and historical texts centuries before the modern idea of a chemical element existed.
- It's one of the few elements commonly found in nature in pure form, occurring as bright yellow crystalline deposits around volcanoes and hot springs.
- Sulfur is a key ingredient in gunpowder, alongside charcoal and saltpeter, making it part of one of the earliest engineered chemical mixtures in history.
Frequently asked questions
Why does rotten egg smell get blamed on sulfur?
Pure elemental sulfur is actually nearly odorless. The rotten-egg smell comes from hydrogen sulfide gas, a sulfur-containing compound produced when bacteria break down organic matter. It's sulfur compounds like that one, not the element itself, that are responsible for the smell.
Who discovered sulfur if its discovery date is listed as 'ancient'?
No single person gets credit. Sulfur is one of the small number of elements that occurs naturally in pure form, so it's been recognized and used since prehistory without needing to be chemically extracted. It was French chemist Antoine Lavoisier who, in the late 1770s, helped establish that sulfur was a true chemical element rather than a compound.
What is sulfur mainly used for today?
The overwhelming majority of sulfur produced today goes into making sulfuric acid, one of the most heavily produced industrial chemicals in the world, used in fertilizer production, battery manufacturing, and countless other chemical processes.
Compounds
28 notable compounds containing S
- Al2(SO4)3salt
Aluminum sulfate
An ionic salt that hydrolyzes in water to give a mildly acidic solution, historically combined with a second sulfate to form alum.
Used for: Water treatment flocculant, paper sizing, soil pH control
- BaSO4salt
Barium sulfate
An extremely insoluble white solid, safe to ingest despite barium's toxicity because it passes through the body unabsorbed — exactly why it works as a contrast agent.
Used for: Radiocontrast agent for gastrointestinal X-ray imaging
- CdSpigment
Cadmium sulfide
A bright yellow-orange semiconducting solid formed from cadmium and sulfur. Its strong, stable color made it a prized artists' pigment long before its toxicity became a health concern.
Used for: Historic 'cadmium yellow' pigment and light-sensitive photoresistors
- Ce(SO4)2reagent
Cerium(IV) sulfate
A yellow-orange oxidizing salt, also called ceric sulfate, whose precisely standardized solutions are a workhorse titrant in analytical chemistry.
Used for: Oxidimetric titrant in analytical chemistry (cerimetry)
- CoSO4salt
Cobalt(II) sulfate
A reddish crystalline salt (in its common hydrated form) that provides a water-soluble source of cobalt ions for industrial and agricultural applications.
Used for: Electroplating baths and trace-mineral additive in animal feed
- CuSO4salt
Copper(II) sulfate
Best known in its vivid blue pentahydrate form ("blue vitriol"), this is perhaps the most recognizable copper compound, prized for its striking color and long history in classic chemistry demonstrations.
Used for: Fungicide and algicide (Bordeaux mixture) and copper electroplating
- H2Sgas
Hydrogen sulfide
A bent molecule best known for its rotten-egg smell, toxic at meaningful concentrations and commonly produced by decaying organic matter.
Used for: Industrial sulfur and sulfuric acid production, analytical reagent
- In2(SO4)3salt
Indium(III) sulfate
A white, water-soluble indium salt used mainly as a bath component for depositing bright indium coatings by electroplating.
Used for: Electrolyte in indium electroplating baths
- PbSO4salt
Lead(II) sulfate
A white, nearly insoluble salt known naturally as the mineral anglesite, and the compound that coats both plates of a lead-acid battery once it has been discharged.
Used for: Forms on lead-acid battery electrodes during discharge
- PbSmineral
Lead(II) sulfide
The natural mineral galena, forming dull gray cubic crystals that are the world's primary ore of lead and one of the earliest semiconductors ever used in electronics.
Used for: Principal lead ore and rectifying crystal in early 'cat's whisker' radio receivers
- MgSO4salt
Magnesium sulfate
An ionic salt best known in its hydrated form, Epsom salt, which dissolves readily in water to give a bitter-tasting solution.
Used for: Epsom salt baths, soil magnesium supplement, medical treatment
- HgSmineral
Mercury(II) sulfide
The natural mineral cinnabar, occurring as bright red hexagonal crystals and as a black cubic form; it is the chief ore from which metallic mercury has been extracted for thousands of years.
Used for: Historic red pigment (vermilion) and primary mercury ore
- MoS2mineral
Molybdenum disulfide
A soft, dark gray solid with a layered structure similar to graphite, occurring naturally as the mineral molybdenite and prized as a dry lubricant.
Used for: Solid lubricant additive in greases and high-temperature/vacuum applications
- NiSO4salt
Nickel(II) sulfate
A blue-green crystalline salt that is the primary nickel source used in electroplating baths, valued for its high solubility and consistent nickel(II) ion supply.
Used for: Nickel electroplating
- As2S3mineral
Orpiment (arsenic trisulfide)
A soft, golden-yellow mineral built from layered As2S3 sheets, long prized for its vivid color. It occurs naturally around hot springs and volcanic vents, often alongside realgar.
Used for: Historic yellow pigment in painting and a natural arsenic ore
- RaSO4mineral
Radium sulfate
An extremely insoluble salt that closely mirrors barium sulfate in structure and behavior, which is why trace radium co-precipitates with barite and other barium sulfate minerals in nature.
Used for: Explains radium's natural association with barium-bearing ores
- As4S4mineral
Realgar (arsenic sulfide)
A red-orange mineral built from cage-like As4S4 molecules, historically mined as an arsenic ore and pigment. It slowly degrades to a yellow powder called pararealgar when exposed to light.
Used for: Historic red pigment and traditional pesticide
- Ag2Smineral
Silver sulfide
A dark, highly insoluble compound that forms as a thin black film whenever silver metal contacts trace sulfur compounds in the air. It is, quite literally, the tarnish on silverware.
Used for: Occurs naturally as the mineral acanthite; the cause of silver tarnish
- Na2SO4salt
Sodium sulfate
An ionic salt known historically as Glauber's salt in its hydrated form, colorless and highly soluble in water.
Used for: Detergent filler, glass and paper manufacturing, textile dyeing
- Sb2S3mineral
Stibnite
A lustrous, metallic gray mineral and the principal ore of antimony, long used in the ancient world as a dark eye cosmetic known as kohl.
Used for: Primary ore of antimony metal; historic cosmetic pigment
- SrSO4mineral
Strontium sulfate
A sparingly soluble white mineral known as celestine, the principal natural ore from which strontium metal and its compounds are extracted.
Used for: Primary commercial ore of strontium
- SO2gas
Sulfur dioxide
A bent, pungent gas released by burning sulfur-containing fuels and by volcanic activity, which dissolves readily in water to form an acidic solution.
Used for: Wine and food preservative, bleaching agent, sulfuric acid production
- SF6gas
Sulfur hexafluoride
A colorless, odorless gas with an octahedral shape that is chemically inert and an excellent electrical insulator.
Used for: Insulating gas in high-voltage electrical equipment
- H2SO4acid
Sulfuric acid
A dense, strong diprotic acid and one of the most heavily produced industrial chemicals in the world, notable for its powerful dehydrating ability.
Used for: Car batteries, fertilizer manufacturing, industrial chemical processing
- Tl2SO4salt
Thallium(I) sulfate
A colorless, odorless, water-soluble salt whose lack of taste or smell made it dangerously easy to misuse before its restriction, since thallium(I) mimics potassium closely enough to be absorbed by the body.
Used for: Formerly a widely used rodenticide and ant killer, now banned in most countries
- WS2industrial
Tungsten disulfide
A dark grey solid with a layered, slippery crystal structure similar to graphite, letting its layers slide past each other with very low friction.
Used for: Dry, high-temperature solid lubricant for bearings and coatings
- ZnSO4salt
Zinc sulfate
A colorless, highly soluble crystalline salt that supplies zinc ions for a range of agricultural and health applications, since zinc is an essential trace element for both plants and animals.
Used for: Dietary supplement and agricultural micronutrient fertilizer
- ZnSmineral
Zinc sulfide
A compound found naturally as the mineral sphalerite, the world's main zinc ore. Synthetic zinc sulfide is also well known for its ability to phosphoresce after exposure to light.
Used for: Primary zinc ore; historically used in glow-in-the-dark materials
Isotopes
22 known isotopes
Swipe to see all columns →
| Isotope | Natural abundance | Half-life | Decay mode | Mass excess | Binding energy / nucleon | Decay width |
|---|---|---|---|---|---|---|
| S-32 stable | 94.85% | Stable | — | -26,015.54 keV | 8,493.13 keV | — |
| S-33 stable | 0.763% | Stable | — | -26,585.86 keV | 8,497.63 keV | — |
| S-34 stable | 4.365% | Stable | — | -29,931.69 keV | 8,583.5 keV | — |
| S-36 stable | 0.0158% | Stable | — | -30,664.14 keV | 8,575.39 keV | — |
Show all 22 isotopes
| S-26 | — | 79 ns | Proton emission | 27,680 keV | 6,525 keV | 5.78 × 10-9 eV |
| S-27 | — | 15.5 ms | Electron capture / beta-plus decay (100%), Beta-plus, proton emission (2.3%), B+2P (1.1%) | 17,491 keV | 6,960 keV | 2.94 × 10-14 eV |
| S-28 | — | 125 ms | Electron capture / beta-plus decay (100%), ECP (20.7%) | 4,073.2 keV | 7,478.79 keV | 3.65 × 10-15 eV |
| S-29 | — | 188 ms | Electron capture / beta-plus decay (100%), ECP (47%) | -3,094.42 keV | 7,746.38 keV | 2.43 × 10-15 eV |
| S-30 | — | 1.178 s | Electron capture / beta-plus decay (100%) | -14,059.25 keV | 8,122.71 keV | 3.87 × 10-16 eV |
| S-31 | — | 2.5534 s | Electron capture / beta-plus decay (100%) | -19,042.53 keV | 8,281.8 keV | 1.79 × 10-16 eV |
| S-35 | — | 87.37 d | Beta-minus decay (100%) | -28,846.21 keV | 8,537.85 keV | 6.04 × 10-23 eV |
| S-37 | — | 5.05 m | Beta-minus decay (100%) | -26,896.43 keV | 8,459.94 keV | 1.51 × 10-18 eV |
| S-38 | — | 170.3 m | Beta-minus decay (100%) | -26,861.22 keV | 8,448.78 keV | 4.47 × 10-20 eV |
| S-39 | — | 11.5 s | Beta-minus decay (100%) | -23,162.67 keV | 8,344.27 keV | 3.97 × 10-17 eV |
| S-40 | — | 8.8 s | Beta-minus decay (100%) | -22,837.85 keV | 8,329.33 keV | 5.18 × 10-17 eV |
| S-41 | — | 1.99 s | Beta-minus decay (100%), Beta-minus, neutron emission | -19,008.58 keV | 8,229.64 keV | 2.29 × 10-16 eV |
| S-42 | — | 1.016 s | Beta-minus decay (100%), Beta-minus, neutron emission (4%) | -17,637.75 keV | 8,193.23 keV | 4.49 × 10-16 eV |
| S-43 | — | 265 ms | Beta-minus decay (100%), Beta-minus, neutron emission (40%) | -12,195.46 keV | 8,063.83 keV | 1.72 × 10-15 eV |
| S-44 | — | 100 ms | Beta-minus decay (100%), Beta-minus, neutron emission (18%) | -9,204.24 keV | 7,996.02 keV | 4.56 × 10-15 eV |
| S-45 | — | 68 ms | Beta-minus decay (100%), Beta-minus, neutron emission (54%) | -3,340 keV | 7,867 keV | 6.71 × 10-15 eV |
| S-46 | — | 50 ms | Beta-minus decay (100%) | 640 keV | 7,785 keV | 9.12 × 10-15 eV |
| S-48 | — | — | Beta-minus decay | 12,390 keV | 7,552 keV | — |