Periodic Table

Antimony

Metalloid

Quick Facts about Antimony

Sn
  • solid- state of matter at room temperature
  • Stable- has at least one stable isotope
  • +5, +3, -3- common oxidation states in compounds
  • RHL- crystal structure, atomic arrangement in solid form
Te

Antimony (Sb) is element 51 on the periodic table. Atomic mass of Sb: 121.7600 u. Sb is in period 5, group 15. Melting point of Sb: 903.78 K.Density of Sb: 6.70 g/cm³.

Why Antimony Matters

Antimony in everyday life and industry

In Your Home

  • Flame retardants in plastics and textiles use antimony trioxide

Industry Uses

MetallurgyLead-acid car batteries contain antimony alloys
Semiconductor industrySemiconductor industry uses high-purity antimony
IndustryType metal for printing historically used antimony

In Your Body

✗ Not essential

Antimony compounds treat leishmaniasis (tropical disease) Workers in antimony industries face health risks

Safety: Antimony is toxic to humans Historically used as medicine despite toxicity

Discovery of Antimony

Discovered by Known to the ancients.,

Name origin: Greek: anti and monos (not alone); symbol from mineral stibnite.

History & Events

Ancient
Symbol 'Sb' from Latin 'stibium'
Ancient
Used since ancient times in cosmetics (kohl eyeliner)
Ancient
Alchemists considered it important
Ancient
Word 'antimony' may mean 'monk killer' - legend of poisoned monks

Why "Sb" for Antimony?

SbStibium(Latin)

The symbol Sb comes from "Stibium," the Latin name derived from Greek "stibi" referring to the mineral stibnite. The name "Antimony" has uncertain origins, possibly from Greek "anti-monos" (not alone) as it's rarely found pure.

About Antimony

Element of group 15. Multiple allotropic forms. The stable form of antimony is a blue-white metal. Yellow and black antimony are unstable non-metals. Used in flame-proofing, paints, ceramics, enamels, and rubber. Attacked by oxidizing acids and halogens. First reported by Tholden in 1450.

Atomic Properties of Sb

Atomic Number of Sb
51
Atomic Mass of Sb
121.7600 u
Electron Configuration
[Kr] 4d10 5s2 5p3
Electronegativity
2.05
Block
p-block
Group
15
Period
5

Physical Properties of Sb

Phase (STP)
solid
Melting Point of Sb
903.78 K
Boiling Point of Sb
1908.00 K
Density of Sb
6.6970 g/cm3

Thermal Properties

Heat of Fusion
20.08 kJ/mol
Heat of Vaporization
195.20 kJ/mol
Specific Heat
0.21 J/g·K
Molar Heat Capacity
25.23 J/mol·K
Thermal Conductivity
24.43 W/m·K

Atomic Radii

Calculated
145 pm
Covalent
140 pm
Van der Waals
206 pm
Metallic
139 pm

Common Misconceptions

Wrong:Antimony's symbol Sb is arbitrary.
Correct:Sb comes from Latin 'stibium'—ancient Egyptians used antimony sulfide (stibnite) as kohl eyeliner 5,000 years ago.
Wrong:'Antimony' means 'anti-monk' (monk killer).
Correct:The toxic 'monk killer' etymology is likely folk legend. The name probably derives from Greek 'anti-monos' (not alone) since it's always found with other elements.
Wrong:Antimony is related to antibiotics.
Correct:The 'anti-' in antimony has nothing to do with antibiotics. Ironically, antimony compounds WERE used medicinally—as emetics (to induce vomiting).

Allotropes of Antimony

Antimony exists in 3 different structural forms (allotropes), each with unique properties.

Metallic Antimony

Most stable form, silvery-white metal

Structure:Rhombohedral layers
Properties:Brittle, poor conductor, expands on cooling

Yellow Antimony (Sb4)

Unstable molecular form

Structure:Tetrahedral Sb4 molecules
Properties:Metastable, forms below -90°C

Black Antimony

Amorphous form

Structure:Disordered structure
Properties:Forms from rapid cooling of antimony vapor

Isotopes of Antimony

Antimony has 2 naturally occurring isotopes, plus 2 notable radioactive isotopes.

IsotopeAtomic Mass (u)AbundanceHalf-LifeDecay Mode
12151Sb (Sb-121)Antimony-121 isotope120.90381257.21%
12351Sb (Sb-123)Antimony-123 isotope122.904213242.79%
12451Sb (Sb-124)Antimony-124 isotope123.9059350%60.2 daysβ⁻
12551Sb (Sb-125)Antimony-125 isotope124.9052540%2.76 yearsβ⁻

Data source: NIH PubChem (aggregated from IUPAC, NIST)

Isotope Applications

Isotopes of Antimony have important real-world applications in science and industry.

Industrial Applications

In the 1950s, 124Sb and 125Sb (with half-lives of 60 days and about 1000 days, respectively) were used commercially as tracers. They were injected into oil pipelines as a way to detect the residence time and flow rate of the substance through the pipeline. The presence of these isotopes could be detected by means of a Geiger counter held above the pipeline. If the pipeline had a leak, the tracer would escape and its contamination and movement could be detected in the soil. 124Sb and 125Sb are now both treated as environmental contaminants [375].

Abundance

Earth's Crust
200.00 μg/kg
Seawater
2.40×10-4 mg/L

Uses

It is alloyed with other metals to increase their hardness. Also in the manufacture of a few special types of semiconductor devices. Also in plastics and chemicals. A few kinds of over-the-counter cold and flu remedies use antimony compounds.

Sources

Found in stibnite (Sb2S3) and in valentinite (Sb2O3).

Geochemistry

Goldschmidt
chalcophile
Geochemical Class
semi-volatile

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