Sulfur (S)
“Known to scripture as "brimstone", the burning stone — this bright yellow element puts the bang in gunpowder, the bounce in rubber and the strike in every match.”
How its electrons are arranged
Computed from the aufbau principle, with known real-world exceptions applied automatically.
Characteristics
- A bright yellow solid whose atoms link into eight-membered S₈ rings; it is brittle, melts at just 115 °C, and refuses to dissolve in water (though carbon disulfide dissolves it easily).
- Burns in air with a startling blue flame to give sulfur dioxide (SO₂), the sharp, choking gas behind the smell of struck matches and firecrackers.
- Sits in Group 16 with oxygen but, unlike that gaseous neighbour, is a solid at room temperature; its valence shell [Ne] 3s² 3p⁴ carries six electrons.
- Shows oxidation states all the way from −2 to +6: as sulfide (S²⁻) in iron pyrites and as sulfate (SO₄²⁻) in gypsum and Epsom salt.
A bright yellow, brittle, crystalline solid that snaps like chalk and melts at only about 115 °C. Its atoms famously link into S₈ rings — eight-membered crowns of sulfur — which is why native sulfur forms soft, yellow crystals around volcano craters.
Where you meet it
✦ Uses
- Making sulfuric acid (H₂SO₄), the "king of chemicals" — TSP-type fertiliser plants and the lead-acid batteries of cars, IPS units and rickshaw lamps all stand on it.
- Gunpowder and match chemistry — black powder mixes sulfur with saltpetre (KNO₃) and charcoal, while matchheads rely on sulfur plus phosphorus to catch fire.
- Vulcanising rubber — Charles Goodyear’s 1839 trick of heating raw rubber with sulfur is what makes tyres, hoses and shoe soles tough yet flexible.
- Sulfur dust as a fungicide on mango, cucumber and vegetable fields, and the age-old sulfur ointment still dabbed on the itch of scabies.
◍ Everyday examples
- Rotten eggs release hydrogen sulfide (H₂S), the "smell of sulfur"; the pungency of onion and garlic comes from sulfur compounds as well.
- Volcano craters and hot springs, from Sicily to Java’s Kawah Ijen, are fringed with crystals of pure native sulfur.
- Dried apricots and raisins keep their golden colour because they were fumigated with SO₂, and a struck match releases its own tiny puff of the same gas.
History & name
Sulfur is one of the handful of elements known since antiquity — ancient Egyptians used its fumes to bleach linen and purify rooms, and the Bible calls it brimstone, the "burning stone". Because it was so familiar, chemists long argued over whether it was truly an element; in 1777 Antoine Lavoisier’s combustion experiments finally established sulfur as a simple, un-decomposable substance rather than a compound. For centuries afterwards, Sicily’s volcanic deposits supplied most of the world, until the Frasch process (1894) began melting deep sulfur out of the salt domes of Texas and Louisiana with superheated water.