Quick Facts
| Property | Value |
|---|---|
| Symbol | Sb |
| Atomic Number | 51 |
| Atomic Mass | 121.76 u |
| Category | Metalloid |
| Period | 5 |
| Group | 15 |
| Block | p |
| Electron Configuration | [Kr] 4d¹⁰ 5s² 5p³ |
Physical Properties
| Property | Value |
|---|---|
| State at 20°C | Solid |
| Density | 6.697 g/cm³ |
| Melting Point | 630.63°C (903.78 K) |
| Boiling Point | 1587°C (1860 K) |
| Appearance | Silvery, lustrous, bluish-white |
Atomic Properties
| Property | Value |
|---|---|
| Electron Configuration | [Kr] 4d¹⁰ 5s² 5p³ |
| Electronegativity | 2.05 (Pauling scale) |
| First Ionization Energy | 834 kJ/mol |
| Atomic Radius | 140 pm |
| Covalent Radius | 139 pm |
| Van der Waals Radius | 206 pm |
History and Discovery
Discovered by: Known since antiquity Year of Discovery: ~3000 BCE Location: Ancient Egypt and Mesopotamia
Etymology
The symbol "Sb" comes from Latin "stibium," from Greek "stibi" (mark), because antimony sulfide was used as eye cosmetic. "Antimony" may come from Greek "anti-monos" (not alone) as it occurs with other elements.
Discovery Story
Antimony has been known since ancient times. Egyptian women used stibnite (antimony sulfide) as black eye makeup. The German monk Basil Valentine described antimony's extraction in the 15th century. Its use in printing type began in the 1450s with Gutenberg.
Isotopes
| Isotope | Natural Abundance | Half-life | Decay Mode |
|---|---|---|---|
| ¹²¹Sb | 57.21% | Stable | - |
| ¹²³Sb | 42.79% | Stable | - |
Occurrence
Natural Abundance
Antimony comprises about 0.2 ppm of Earth's crust. It is found as stibnite (Sb₂S₃) and in various other minerals. China produces about 80% of the world's antimony.
Extraction and Production
- Roasting: Of stibnite to antimony trioxide
- Reduction: With carbon or iron
- Sources: Primarily stibnite mining
- Global production: about 150,000 tons annually
Applications and Uses
Flame Retardants
- Antimony trioxide synergist (main use—about 60%)
- Plastics, textiles, and electronics
- Cable sheathing
Alloys
- Lead-antimony batteries
- Printing type metal (historical)
- Babbitt metal (bearings)
- Pewter
Semiconductors
- Antimony compounds in LEDs
- Infrared detectors (InSb)
- Thermoelectric devices
Other Uses
- Glass and ceramic colorant
- Primers for ammunition
- Antiprotozoan drugs
Biological Role
Antimony has no known beneficial biological role and is toxic to humans.
In the Human Body
Antimony is not normally found in the body. It can accumulate with chronic exposure.
Toxicity
Antimony compounds are toxic, causing gastrointestinal and cardiac effects. Historically used medicinally (tartar emetic).
Safety and Hazards
Toxicity
Antimony and its compounds are toxic. Antimony trioxide is a possible carcinogen. Stibine (SbH₃) is highly toxic.
Handling Precautions
- Avoid inhalation of dust
- Some compounds are carcinogenic
- Stibine gas is extremely hazardous
- Use appropriate PPE
Environmental Impact
Antimony mining and smelting can contaminate local environments. China's dominance in production raises supply concerns.
Interesting Facts
- Ancient Egyptians used antimony sulfide (kohl) as eye makeup 5,000 years ago
- China controls about 80% of global antimony production
- Antimony was used in early printing type because it expands on cooling
- Some bullets use antimony to harden the lead
- The name may come from Greek meaning "not alone" or "against monks" (legend)