Periodic table › Sulfur
1. Identity and classification
Non-conducting gas or brittle molecular/network solid
- Name and symbol
- Sulfur (Sulfur) · S
- Atomic number
- 16
- Relative atomic weight / mass number
- 32.06 ± 0.02
- Group · period · block
- 16 · 3 · p
- Category
- Reactive Nonmetal
- State near room temperature
- Solid
- Stable isotopes
- At least one stable isotope
- CAS number
- 7704-34-9
Square brackets [A] indicate a representative isotope mass number, not an average atomic weight. Neutron counts differ between isotopes.
2. Atomic structure and electron configuration
- Protons · electrons in a neutral atom
- 16 · 16
- Neutrons in reference isotope
- 16 (32S)
- Full electron configuration
1s² 2s² 2p⁶ 3s² 3p⁴- Abbreviated configuration
[Ne]3s² 3p⁴- Electrons per shell
- 2, 8, 6
- Listed oxidation states
- +6, +4, -2
- Electronegativity
- 2.58 (Pauling)
- First ionization energy
- 999.588 kJ/mol · 10.36 eV
- Electron affinity
- 200.4 kJ/mol
- Covalent radius
- 105 pm
- van der Waals radius
- 180 pm
Configurations of superheavy elements may include theoretical predictions. Different definitions of atomic radius are not interchangeable.
3. Physical and thermal properties
- Density
- 2.067 g/cm³
- Melting point
- 388.36 K · 115.21 °C · 239.378 °F
- Boiling point
- 717.75 K · 444.6 °C · 832.28 °F
- Crystal structure
- Orthorhombic
- Specific heat
- 0.71 J/(g·K)
- Thermal conductivity
- 0.205 W/(m·K)
- Enthalpy of fusion
- 1.727 kJ/mol
- Enthalpy of vaporization
- 45 kJ/mol
- Magnetic ordering
- Diamagnetic
- Mohs hardness
- 2
- Speed of sound
- 1950 m/s
Density and structure depend on temperature, pressure and allotrope. 25°C is a room-temperature reference, not STP. Unestablished values are not zero.
4. Chemical behavior and compounds
The listed electron configuration and oxidation states describe atomic structure; compound properties depend on bonding and composition.
Selected compounds: SO / S₂O₃ (Oxide) · SClₙ (Chloride) · SFₙ (Fluoride)
Reaction reference
Oxidation behavior depends on temperature, surface passivation and the chemical environment.
Direct reaction with water is element- and condition-dependent.
5. Isotopes
| Isotope | Status | Natural abundance | Half-life |
|---|---|---|---|
| 32S | Stable | 94.850% | Stable |
| 33S | Stable | 0.763% | Stable |
| 34S | Stable | 4.365% | Stable |
| 36S | Stable | 0.0158% | Stable |
Half-life units: s seconds, m minutes, h hours, d days, Y years. A dash means no natural-abundance value is given, not zero. Listed records are selected ground states; metastable states are distinct.
6. Discovery and occurrence
- Discovery
- Known since antiquity; no exact discovery year
- Scientists associated with discovery
- Known since antiquity
- Location
- Ancient India, China, Egypt & Greece
- Origin
- Natural
- Listed crustal abundance
- Not established
Minerals and naming reference
Native Sulfur, Pyrite (FeS₂), Galena, Sphalerite, Gypsum (CaSO₄·2H₂O)
Named from scientific/historical roots associated with Sulfur (S), discovered or characterized by Known since antiquity.
7. Applications
Sulfuric acid (H₂SO₄) industrial production, vulcanization of rubber tires, gunpowder, essential amino acids (cysteine & methionine)
Detailed applications by field
- everyday
- Sulfuric acid (H₂SO₄) industrial production, vulcanization of rubber tires, gunpowder, essential amino acids (cysteine & methionine)
- industry
- Used in reactive nonmetal processing, specialized alloys, and chemical manufacturing (Sulfuric acid (H₂SO₄) industrial production, vulcanization of rubber tires, gunpowder, essential amino acids (cysteine & methionine)).
- electronics
- Applied in electronic components, semiconductors, or functional coatings where Sulfur's electronic structure ([Ne] 3s² 3p⁴) provides target conductivity.
- medicine
- Diagnostic imaging, biomedical instrumentation, or pharmaceutical synthesis research.
- energy
- Utilized in power generation, battery materials, catalysts, or nuclear technology involving Sulfur.
- aerospace
- High-performance materials, structural alloys, or space instrumentation utilizing Sulfur.
- agriculture
- Soil geochemistry analysis, trace micronutrient research, or analytical environmental monitoring.
- science
- Spectroscopic standard, crystallography, and quantum chemistry studies of Period 3 p-block elements.
8. Biological role and safety
Hazard depends on the isotope, chemical form, dose and exposure route.
Elemental substances, ions, compounds and radioisotopes can have different health effects. This is an educational reference; laboratory work requires the material safety data sheet and trained supervision.
Biological role reference
Classified as essential in human and biological systems.