Average mass of an atom in unified atomic mass units (1 u is 1/12 of the mass of a carbon-12 atom). Accounts for the natural mix of the element’s isotopes.
Number of the vertical column, 1 to 18 in IUPAC numbering. Elements in a group share the same outer-shell layout, so their properties are alike.
Number of the horizontal row. Usually equal to the number of electron shells in the atom; palladium is the exception, with four shells in period 5.
The subshell (s, p, d or f) that receives the last electrons in the usual filling order; it divides the table into four blocks. Real atoms sometimes differ: lanthanum starts the f-block but has no f electrons.
[Ne] 3s² 3p⁴
How electrons are arranged in subshells. The bracket stands for the previous noble gas; the superscript is the number of electrons in a subshell.
2, 8, 6
Number of electrons in each shell, from the nucleus outwards.
115.2 °C (388.36 K)
Temperature at which the solid turns liquid at standard pressure. Helium, carbon and arsenic do not melt at normal pressure: helium needs about 25 atm, carbon and arsenic turn straight into vapour.
444.6 °C (717.75 K)
Temperature at which the liquid boils at standard pressure. For carbon and arsenic, the temperature at which the solid turns straight into vapour (sublimation).
2.067 g/cm³
Mass of one cubic centimetre of the substance. For gases, at 0 °C and standard pressure.
2.58 Pauling
How strongly an atom pulls electrons towards itself in a chemical bond. On the Pauling scale it runs from 0.79 for caesium to 3.98 for fluorine.
10.36 eV
Energy needed to remove the most loosely bound electron from an atom. The lower it is, the more easily the element gives up an electron, which is typical of metals.
2.077 eV
Energy released when a neutral atom gains an electron. Highest for the halogens. Noble gases, nitrogen and some metals form no stable negative ion.
105 pm
Half the length of a single covalent bond between two atoms of the element. It shows the size of an atom inside a molecule or crystal: 76 pm for carbon, 132 pm for iron.
+6, +4, +2, -2
Charges the atom would have in its compounds if all its bonds were ionic; the main ones are listed.
Sulfur (S) is a chemical element with atomic number 16. It sits in group 16 and period 3 of the periodic table, in the p-block. It is a nonmetal. At room temperature it is a solid. Its standard atomic weight is 32.06.
Origin of the name
The word comes from Latin sulpur; Romans later spelled it sulphur, wrongly thinking it was Greek. The old English name, brimstone, means ‘burning stone’ and appears in the Bible. The Greek word, theîon, lives on in the chemical prefix thio-, which marks sulfur in a compound name.
Where is sulfur found?
Pure sulfur forms yellow crystals around volcanoes and hot springs. Much more of it is bound in minerals such as pyrite, galena, sphalerite, cinnabar and gypsum. Today most sulfur is recovered when natural gas and oil are cleaned of it. Sulfur is the tenth most abundant element in the universe, and every living thing needs it: it holds together the proteins of hair.
What is sulfur used for?
Most sulfur is turned into sulfuric acid, the chemical made in the largest amounts, which goes mainly into fertilisers. Sulfur hardens rubber for tyres (vulcanisation), protects grapevines and crops from fungi, and was one of the three ingredients of gunpowder. Sulfur dioxide keeps wine and dried fruit from spoiling.
Interesting facts
The rotten-egg smell comes not from sulfur itself but from hydrogen sulfide, a poisonous gas.
Nearly 2,800 years ago Homer described burning sulfur to drive away pests and purify a house.