Sulfur (S)
Element 16 · Nonmetal · atomic mass 32.06 u · group 16, period 3
Electron shells: 2, 8, 6
Sulfur is a yellow non-metal found pure near volcanoes and in vast underground deposits. More sulfuric acid is made than any other industrial chemical, which makes sulfur a bellwether for an economy.
A country's sulfuric acid consumption used to be a standard proxy for how industrialised it was.
- Atomic number
- 16
- Atomic mass
- 32.06 u
- Electron configuration
- [Ne] 3s² 3p⁴
- Group · period · block
- 16 · 3 · p
- Oxidation states
- −2, +2, +4, +6
- Electronegativity
- 2.58 (Pauling)
- Melting point
- 115 °C
- Boiling point
- 445 °C
- Density
- 2.067 g/cm³
- State at 20 °C
- Solid
- Appearance
- Bright yellow crystalline solid
- Discovered
- Known since antiquity
16 protons, and 16 electrons when neutral
IUPAC interval [32.059, 32.076]
Chalcogens
What Sulfur is used for
- Sulfuric acid production
- Vulcanising rubber
- Fungicides and fertilisers
- Gunpowder and matches
Atomic structure of Sulfur
A neutral sulfur atom has 16 protons and 16 electrons. Its most common isotope carries about 16 neutrons, which is where the mass number 32 comes from. Change the neutron count and you have a different isotope of sulfur; change the proton count and you have a different element entirely.
Those electrons fill shells from the inside out: 2, 8, 6. In orbital notation that is [Ne] 3s² 3p⁴, leaving 6 valence electrons in the outer shell — the ones that do the chemistry.
3D electron orbitals
See where Sulfur's electrons actually are — a cloud of 26,000 points sampled from the probability density |ψ|², not a cartoon of a lobe.
Where Sulfur sits in the periodic table
Poor conductors that gain or share electrons rather than losing them. They make up almost all the mass of living things.
- Directly above: Oxygen — same group, so similar chemistry with a smaller atom.
- Directly below: Selenium — same group, one shell larger.
- One proton lighter: Phosphorus.
- One proton heavier: Chlorine.
Discovery and naming
Sulfur has been known and used since antiquity, long before anyone could describe it as an element. Its name comes from Latin sulphur.
Keep exploring
Atomic weight from IUPAC/CIAAW; physical properties from PubChem (US National Library of Medicine). Values that have never been measured are shown as “not measured” rather than estimated.
Related Calculators
Frequently Asked Questions
What is the atomic mass of Sulfur?
The standard atomic weight of Sulfur is 32.06 u. Because the natural isotope mix varies between sources, IUPAC publishes it as the interval [32.059, 32.076], and 32.06 is the conventional single value to use in calculations.
How many protons, neutrons and electrons does Sulfur have?
Sulfur has 16 protons, because the atomic number is the proton count and that is what makes an atom Sulfur at all. A neutral Sulfur atom has the same number of electrons, 16. The neutron count varies by isotope; the most common one has about 16, since 32 − 16 = 16.
What is the electron configuration of Sulfur?
The electron configuration of Sulfur is [Ne] 3s² 3p⁴. Its electrons are arranged 2, 8, 6 across 3 shells.
Is Sulfur a metal?
No. Sulfur is classified as a nonmetal, on the right-hand side of the table where elements gain or share electrons rather than losing them.
What group and period is Sulfur in?
Sulfur is in group 16 (the chalcogens), period 3, in the p-block. The group is its column and the period is its row.
What is the charge of Sulfur?
Sulfur most commonly forms a 2− ion. It is 2 electrons short of a full outer shell, so it gains them rather than losing 6. Across all its compounds it shows oxidation states of −2, +2, +4, +6.
What is the melting point of Sulfur?
Sulfur melts at 115 °C and boils at 445 °C. That puts it in the solids at everyday temperatures.
What is Sulfur used for?
Sulfuric acid production, Vulcanising rubber, Fungicides and fertilisers, Gunpowder and matches. Sulfur is a yellow non-metal found pure near volcanoes and in vast underground deposits.
Who discovered Sulfur, and where does its name come from?
Sulfur (S) has been known and used since antiquity, long before anyone could describe it as an element. The name comes from Latin sulphur.