Antimony (Sb)
metalloidSolid
Standard Atomic Weight
121.76 uElectron configuration
[Kr] 5s2 4d10 5p3Melting point
630.63 °CBoiling point
1586.85 °CDensity
6685 kg/m³Oxidation states
−3, −2, −1, 0, +1, +2, +3, +4, +5Electronegativity (Pauling)
2.05Ionization energy (1st)
8.608389 eVDiscovery year
1707Atomic radius
145 pmDetails
Antimony is a brittle p-block metalloid in group 15. It commonly shows oxidation states +3 and +5, with chemistry that bridges arsenic and bismuth. The element is best known as a hardening additive for lead alloys and as a component of flame-retardant systems through antimony trioxide. Natural antimony is usually encountered in sulfide minerals rather than as native metal.
Antimony is a poor conductor of heat and electricity. Antimony and many of its compounds are toxic.
The name derives from the Greek, anti + monos for "not alone" or "not one" because it was found in many compounds. The symbol Sb comes from stibium, which is derived from the Greek stibi for "mark" because it was used for blackening eyebrows and eyelashes. The minerals stibnite (Sb2S3) and stibine (SbH3) are two of more than one hundred mineral species, which were known in the ancient world.
Antimony has been known since ancient times. It is sometimes found free in nature, but is usually obtained from the ores stibnite (Sb2S3) and valentinite (Sb2O3). Nicolas Lémery, a French chemist, was the first person to scientifically study antimony and its compounds. He published his findings in 1707. Antimony makes up about 0.00002% of the earth's crust.
From the Greek word anti plus monos - "a metal not found alone". Antimony was recognized in compounds by the ancients and was known as a metal at the beginning of the 17th century and possibly much earlier.
Pure antimony is a silvery white, lustrous solid with a crystalline, flaky fracture. It is hard enough to take a polish but is very brittle and can be pulverized. The stable form at ordinary conditions is metallic in appearance, although it has semimetallic electrical behavior.
The largest uses of antimony are tied to compounds rather than the pure element. Antimony trioxide, Sb₂O₃, is widely used as a synergist with halogenated flame retardants in plastics, textiles, and coatings. Metallic antimony hardens lead in lead-acid battery grids, ammunition, and some bearing or type-metal alloys. Smaller uses include glass fining, ceramic opacifiers or color modifiers, and antimony-containing semiconductors such as indium antimonide, InSb.
Antimony is a brittle metal and is a poor conductor of heat and electricity. Very pure antimony is used to make certain types of semiconductor devices, such as diodes and infrared detectors. Antimony is alloyed with lead to increase lead's durability. Antimony alloys are also used in batteries, low friction metals, type metal and cable sheathing, among other products. Antimony compounds are used to make flame-proofing materials, paints, ceramic enamels, glass and pottery. The ancient Egyptians used antimony, in the form of stibnite, for black eye make-up.
Antimony is finding use in semiconductor technology for making infrared detectors, diodes and Hall-effect devices. It greatly increases the hardness and mechanical strength of lead. Batteries, antifriction alloys, type metal, small arms and tracer bullets, cable sheathing, and minor products use about half the metal produced. Compounds taking up the other half are oxides, sulfides, sodium antimonate, and antimony trichloride. These are used in manufacturing flame-proofing compounds, paints ceramic enamels, glass, and pottery.
Isotopes in Earth/Planetary Science
Molecules, atoms, and ions of the stable isotopes of antimony possess slightly different physical and chemical properties, and they commonly will be fractionated during physical, chemical, and biological processes, giving rise to variations in isotopic abundances and in atomic weights. There are measureable substantial variations in the isotopic abundances of antimony in natural terrestrial materials (Fig. IUPAC.51.1) [370] O. Rouxel, J. Ludden, Y. Fouquet. Chem. Geol.200, 25 (2003).. The stable isotopes 121Sb and 123Sb have been used to measure movement of sediments and rocks originating from locations high in antimony. 121Sb and 123Sb move with the sediments and have been used as tracers in areas low in antimony to determine the originating location of certain metal/metalloid contaminants in streams [371] B. Chauvenet, M. M. Be, M. N. Amiot, C. Bobin, M. C. Lepy, T. Branger, I. Laniece, A. Luca, M. Sahagia, A. C. Watjen, K. Kossert, O. Ott, O. Nahle, P. Dryak, J. Sochorova, P. Kovar, P. Auerbach, T. Altzitzoglou, S. Pomme, G. Sibbens, R. Van Ammel, J. Paepen, A. Iwahara, J. U. Delgado, R. Poledna, C. J. da Silva, L. Johansson, A. Stroak, C. Bailat, Y. Nedjadi, P. Spring. Appl. Radiat. Isot.68, 1207 (2010)., [372] M. Baeza, J. Ren, S. Krishnamurthy, T. C. Vaughan. Arch. Environ. Contam. Toxicol.8, 299 (2010)., [373] L. Wilson. “Determination of trace element provenance in the Rio Loa Basin, Chile”, in 2010 Geological Society of America Presentation..
Isotopes in Industry
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] R. Gibbs. Popular Mech.117, 117 (1955)..
Isotopes Used as a Source of Radioactive Isotope(s)
123Sb is used to produce 124I (with a half-life of 100 h), which is used in radioimmunotherapy and also in positron emission tomography. It can be produced from the 123Sb (3He, 2n) 124I reaction [376] M. S. Uddin, A. Hermanne, S. Sudár, M. N. Aslam, B. Scholten, H. H. Coenen, S. M. Qaim. Appl. Radiat. Isot.69, 699 (2010).. 121Sb and 123Sb can both be used for the production of 123I (with a half-life of 13.2 h) via 3He and alpha particle-induced reactions with 121Sb and 123Sb, although the most common production route is via 124Xe or 123Te [377] K. F. Hassan, S. M. Qaim, Z. A. Saleh, H. H. Coenen. Appl. Radiat. Isot.64, 101 (2006)..
Antimony forms stable trivalent and pentavalent compounds, with Sb(III) generally more common. Stibnite, Sb₂S₃, is the principal ore mineral and a representative sulfide. Antimony trioxide, Sb₂O₃, is amphoteric and dissolves in strong acids or bases under suitable conditions. Antimony pentachloride, SbCl₅, is a strong Lewis acid, while antimony trifluoride, SbF₃, is a useful fluorinating reagent. Complex antimonates contain Sb(V) in oxide frameworks.
See more information at the Antimony compound page.
Elemental antimony is less readily absorbed than many soluble compounds, but dust and fumes can irritate the respiratory tract and should be controlled. Soluble antimony(III) compounds are generally more toxic than many antimony(V) compounds. Antimony trioxide, Sb₂O₃, has occupational inhalation concerns and is classified in several jurisdictions as a suspected or possible carcinogenic hazard. Stibine, SbH₃, is a highly toxic gas.
Antimony is a trace element in the crust and is concentrated mainly in sulfide deposits. Weathering of antimony minerals can release antimony species to soils and waters, where mobility depends strongly on pH, redox state, and adsorption to iron and manganese oxides. Mining, smelting, coal combustion, waste incineration, and wear or disposal of antimony-containing products can add local contamination. It has no known essential biological role.
Antimony supply is based mainly on mining and processing stibnite ores, with additional recovery as a by-product from some complex lead, copper, and precious-metal operations. Concentrates are roasted or otherwise converted to oxides and then reduced or refined, depending on the desired product. Demand is dominated by flame-retardant applications and lead-alloy use, especially batteries. Supply is relatively concentrated geographically, so recycling from lead-acid batteries and substitution in flame-retardant systems are important industrial considerations.
Antimony is not abundant, but is found in over 100 mineral species. It is sometimes found natively, but more frequently it is found as the sulfide stibnite.
Antimony is a relatively uncommon heavy element in the cosmos. Its stable isotopes are produced chiefly by neutron-capture processes in earlier generations of stars, including slow neutron capture in evolved stars and rapid neutron capture in explosive events. In planetary materials it behaves as a chalcophile element, tending to associate with sulfur-rich phases rather than silicate minerals.
- The symbol Sb comes from stibium, a Latin name associated with antimony sulfide.
- Antimony expands slightly on solidifying, a property useful in sharp-casting alloys.
- Stibnite crystals can form long metallic-gray blades with a very low hardness.
- Indium antimonide, InSb, has a very narrow band gap and is used in infrared detectors.
- Antimony has two stable natural isotopes, ¹²¹Sb and ¹²³Sb.
Images
Properties
Physical
- Atomic radius (empirical)
- 145 pm Compare Atomic radius (empirical) of all elements →
- Covalent radius
- 139 pm Compare Covalent radius of all elements →
- Van der Waals radius
- 206 pm Compare Van der Waals radius of all elements →
- Metallic radius
- 139 pm Compare Metallic radius of all elements →
- Density
- 6685 kg/m³ Compare Density of all elements →
- Molar volume
- 0.0184 L/mol
- Phase at STP
- Solid Compare Phase at STP of all elements →
- Melting point
- 630.63 °C Compare Melting point of all elements →
- Boiling point
- 1586.85 °C Compare Boiling point of all elements →
- Thermal conductivity
- 24.43 W/(m·K) Compare Thermal conductivity of all elements →
- Specific heat capacity
- 0.207 J/(g·K) Compare Specific heat capacity of all elements →
- Molar heat capacity
- 25.23 J/(mol·K) Compare Molar heat capacity of all elements →
- Crystal structure
- Rhombohedral Compare Crystal structure of all elements →
Chemical
- Electronegativity (Pauling)
- 2.05 Compare Electronegativity (Pauling) of all elements →
- Electronegativity (Allen)
- 1.984
- Electron affinity
- 1.07 eV
- Ionization energy (1st)
- 8.608389 eV Compare Ionization energy (1st) of all elements →
- Ionization energy (2nd)
- 16.626057 eV Compare Ionization energy (2nd) of all elements →
- Ionization energy (3rd)
- 25.323587 eV Compare Ionization energy (3rd) of all elements →
- Ionization energy (4th)
- 43.804151 eV Compare Ionization energy (4th) of all elements →
- Ionization energy (5th)
- 55.000189 eV Compare Ionization energy (5th) of all elements →
- Oxidation states
- −3, −2, −1, 0, +1, +2, +3, +4, +5 Compare Oxidation states of all elements →
- Valence electrons
- 5 Compare Valence electrons of all elements →
- Allotropes
- ["gray"]
- Electron configuration
- [Kr] 5s2 4d10 5p3
Thermodynamic
- Heat of fusion
- 0.20417682 eV Compare Heat of fusion of all elements →
- Heat of vaporization
- 0.70477276 eV Compare Heat of vaporization of all elements →
- Heat of sublimation
- 2.02104 eV
- Heat of atomization
- 2.715448 eV
- Atomization enthalpy
- 2.740322 eV
Nuclear
- Protons
- 51 Compare Protons of all elements →
- Neutrons
- 70 Compare Neutrons of all elements →
- Known isotopes
- 41 Compare Known isotopes of all elements →
- Stable isotopes
- 2 Compare Stable isotopes of all elements →
- Most stable isotope
- Sb-121
- Discovery year
- 1707
Abundance
- Abundance (Earth's crust)
- 0.2 mg/kg Compare Abundance (Earth's crust) of all elements →
- Abundance (ocean)
- 2.4 × 10−4 mg/L Compare Abundance (ocean) of all elements →
Crystal Structure
- Lattice constant a
- 451 pm
Electronic Structure
- Electrons per shell
- 2, 8, 18, 18, 5 Compare Electrons per shell of all elements →
Identifiers
- CAS number
- 7440-36-0 Compare CAS number of all elements →
- Term symbol
- 4S°3/2
- InChI
- InChI=1S/Sb
- InChI Key
- WATWJIUSRGPENY-UHFFFAOYSA-N
Electron Configuration Measured
Sb: 4d¹⁰ 5s² 5p³[Kr] 4d¹⁰ 5s² 5p³1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p³Atomic model
Isotopes change neutron count, mass, and stability — not the electron configuration of a neutral atom.
Schematic atomic model, not to scale.
Atomic Fingerprint
Emission / Absorption Spectrum
Isotope Distribution
| Mass number | Atomic mass (u) | Natural abundance | Half-life |
|---|---|---|---|
| 121 Stable | 120.903812 ± 0.000003 | 57.2100% | Stable |
| 123 Stable | 122.9042132 ± 0.0000023 | 42.7900% | Stable |
Phase / State
Reason: 605.6 °C below melting point (630.63 °C)
Schematic, not to scale
Phase transition points
Transition energies
Energy required to melt 1 mol at melting point
Energy required to vaporize 1 mol at boiling point
Energy required to sublime 1 mol at sublimation point
Density
At standard conditions
At standard conditions
Atomic Spectra
Showing 10 of 51. Sorted by ion charge (ascending).
Lines Holdings ?
| Ion | Charge | Total lines | Transition probabilities | Level designations |
|---|---|---|---|---|
| Sb I | 0 | 135 | 10 | 128 |
| Sb II | +1 | 90 | 2 | 61 |
| Sb III | +2 | 61 | 0 | 0 |
| Sb IV | +3 | 14 | 0 | 0 |
| Sb V | +4 | 8 | 0 | 0 |
Levels Holdings ?
| Ion | Charge | Levels |
|---|---|---|
| Sb I | 0 | 153 |
| Sb II | +1 | 110 |
| Sb III | +2 | 24 |
| Sb IV | +3 | 29 |
| Sb V | +4 | 9 |
| Sb VI | +5 | 60 |
| Sb VII | +6 | 2 |
| Sb VIII | +7 | 2 |
| Sb IX | +8 | 2 |
| Sb X | +9 | 2 |
Ionic Radii
| Charge | Coordination | Spin | Radius |
|---|---|---|---|
| +3 | 4 | N/A | 76 pm |
| +3 | 5 | N/A | 80 pm |
| +3 | 6 | N/A | 76 pm |
| +5 | 6 | N/A | 60 pm |
Compounds
Isotopes (2)
| Mass number | Atomic mass (u) | Natural abundance | Half-life | Decay mode | |
|---|---|---|---|---|---|
| 121 Stable | 120.903812 ± 0.000003 | 57.2100% ± 0.0500% | Stable | stable | |
| 123 Stable | 122.9042132 ± 0.0000023 | 42.7900% ± 0.0500% | Stable | stable |
Spectral Lines
| Wavelength (nm) | Intensity | Ion stage | Type | Transition | Accuracy | Source | |
|---|---|---|---|---|---|---|---|
| 403.35367 nm | 200 | Sb I | emission | 5p3 2P* → 5p2.(3P).6s 4P | Measured | NIST | |
| 475.77494 nm | 20 | Sb I | emission | 5p2.(3P).6s 4P → 5p2.(3P<2>).7p (2,3/2)* | Measured | NIST | |
| 549.02252 nm | N/A | Sb I | emission | 5p2.(3P).6s 4P → 5p2.(3P<2>).7p (2,1/2)* | Measured | NIST | |
| 555.60108 nm | N/A | Sb I | emission | 5p2.(3P).6s 2P → 5p2.(1D<2>).6p (2,1/2)* | Measured | NIST | |
| 560.20647 nm | N/A | Sb I | emission | 5p2.(3P).6s 4P → 5p2.(3P<1>).7p (1,3/2)* | Measured | NIST | |
| 563.19352 nm | N/A | Sb I | emission | 5p2.(3P).6s 4P → 5p2.(3P<0>).7p (0,3/2)* | Measured | NIST | |
| 573.02392 nm | N/A | Sb I | emission | 5p2.(3P).6s 2P → 5p2.(3P<2>).7p (2,3/2)* | Measured | NIST | |
| 661.1381 nm | 20 | Sb I | emission | 5p2.(3P).6s 2P → 5p2.(1D<2>).6p (2,1/2)* | Measured | NIST |
Extended Properties
Covalent Radii (Extended)
- Covalent radius (Pyykkö)
- 140 pm
- Covalent radius (Pyykkö, double)
- 133 pm
- Covalent radius (Pyykkö, triple)
- 127 pm
- Covalent radius (Bragg)
- 140 pm
Van der Waals Radii
- Truhlar
- 206 pm
- Batsanov
- 220 pm
- Alvarez
- 247 pm
- UFF
- 442 pm
- MM3
- 252 pm
- Dreiding
- 435 pm
Atomic & Metallic Radii
- Atomic radius (Rahm)
- 246 pm
- Metallic radius (C12)
- 166 pm
Numbering Scales
- Mendeleev
- 96
- Pettifor
- 88
- Glawe
- 91
Electronegativity Scales
- Ghosh
- 0
- Miedema
- 4
- Gunnarsson–Lundqvist
- 5
- Robles–Bartolotti
- 4
Polarizability & Dispersion
- Dipole polarizability
- 43 a.u.
- Dipole polarizability (unc.)
- 2 a.u.
- C₆
- 492 Ha·Bohr6
- C₆ (Gould–Bučko)
- 504 Ha·Bohr6
Miedema Parameters
- Miedema molar volume
- 16.95 cm3/mol
- Miedema electron density
- 2
Supply Risk & Economics
- Production concentration
- 88
- Relative supply risk
- 9
- Reserve distribution
- 53
- Political stability (top producer)
- 24
- Political stability (top reserve)
- 24
Phase Transitions & Allotropes
| Melting point | 903.78 K |
| Boiling point | 1860.15 K |
Oxidation State Categories
Advanced Reference Data
Screening Constants (11)
| n | Orbital | σ |
|---|---|---|
| 1 | s | 1.0256 |
| 2 | p | 4.1274 |
| 2 | s | 13.4046 |
| 3 | d | 14.2002 |
| 3 | p | 17.8161 |
| 3 | s | 17.7909 |
| 4 | d | 32.0256 |
| 4 | p | 28.8188 |
| 4 | s | 27.4564 |
| 5 | p | 41.0055 |
Crystal Radii Detail (4)
| Charge | CN | Spin | rcrystal (pm) | Origin |
|---|---|---|---|---|
| 3 | IVPY | 90 | ||
| 3 | V | 94 | ||
| 3 | VI | 90 | Ahrens (1952) ionic radius, | |
| 5 | VI | 74 |
Isotope Decay Modes (61)
| Isotope | Mode | Intensity |
|---|---|---|
| 102 | p | — |
| 103 | p | — |
| 104 | B+ | — |
| 104 | B+p | 7% |
| 104 | p | 7% |
| 104 | A | — |
| 105 | B+ | 100% |
| 105 | p | 0.1% |
| 105 | B+p | — |
| 106 | B+ | 100% |
X‑ray Scattering Factors (508)
| Energy (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 9.95091 |
| 10.1617 | — | 10.0681 |
| 10.3261 | — | 9.92927 |
| 10.4931 | — | 9.42377 |
| 10.6628 | — | 8.92685 |
| 10.8353 | — | 8.35287 |
| 11.0106 | — | 7.84004 |
| 11.1886 | — | 7.4678 |
| 11.3696 | — | 7.10503 |
| 11.5535 | — | 6.73907 |
Additional Data
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
2×10-1 milligrams per kilogram
References (1)
- [5] Antimony https://education.jlab.org/itselemental/ele051.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
2.4×10-4 milligrams per liter
References (1)
- [5] Antimony https://education.jlab.org/itselemental/ele051.html
Sources
Sources of this element.
Antimony is not abundant, but is found in over 100 mineral species. It is sometimes found natively, but more frequently it is found as the sulfide stibnite.
References (1)
- [6] Antimony https://periodic.lanl.gov/51.shtml
References
(9)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
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The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Antimony.
The element property data was retrieved from publications.