Sulfur (S)

Bright yellow solid

Sulfur is a yellow, brittle nonmetal found near volcanoes and in hot springs, and with two unpaired 3p electrons, sulfur forms diverse compounds including SO₂, H₂S, and elemental S₈ rings. It is critical for disulfide bridges in proteins and is the seventh most abundant element in the universe.

Key metrics

Density2.07g/cm³

Melting point388.36K

Boiling point717.8K

Electronegativity2.58Pauling

Discovery

2000discovered

Discovered by: Ancient
Reactivity profile: Burns Easily
Reactivity: Medium
Bonding: Covalent

Electron configuration

\textcolor{#6b7280}{[Ne]}\; \textcolor{#ef4444}{3_{s}^{2}}\; \textcolor{#3b82f6}{3_{p}^{4}}

[Ne] 3s2 3p4

Wave function

\Psi_{\text{S}} \approx \frac{1}{\sqrt{16!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{16}(\mathbf{r}_{16}) \right|

Probability density $|\Psi|^2$ across the S valence shell.

Crystal structure

Orthorhombic

Lattice constantsa 1.00 · b 1.30 · c 0.90

Cell anglesα = β = γ = 90°

Coordination number—

Atoms per cell—

Atomic packing factor0.60

Physical properties

Atomic radius: 103 pm
Ionization energy: 1000 kJ/mol
Electron affinity: 200 kJ/mol
Crystal structure: Orthorhombic

Oxidation states

-2+4+6

Acid/base

Acidic

Strongly acidicStrongly basic

State at 25 °CSolid

388.36 K717.8 K298 K

Emission spectrum

4 transitions

380450500550600650700780

VioletBlueGreenYellowRed

469.5nmS I (blue)Blue50%

527.7nmS I (green)Green100%

556.5nmS IGreen70%

605.2nmS I (orange)Orange40%

Dominant line 527.7 nmRange 470–605 nmTransitions 4