Thallium (Tl)
post-transition-metalSolid
Masse atomique relative standard
204,38 u [204,382, 204,385]Configuration électronique
[Xe] 6s2 4f14 5d10 6p1Point de fusion
303,85 °CPoint d’ébullition
1472,85 °CMasse volumique
1,18e+4 kg/m³États d’oxydation
−5, −2, −1, +1, +2, +3Électronégativité (Pauling)
1,62Énergie d’ionisation (1re)
6,108287 eVAnnée de découverte
1861Rayon atomique
190 pmDétails
Thallium is a soft post-transition metal in group 13. It is chemically notable for the stability of the +1 oxidation state, which reflects the inert-pair effect and makes many thallium(I) salts resemble alkali-metal salts in size and solubility behavior. The element is rare in ores and is usually recovered as a by-product of processing sulfide minerals. Its severe toxicity has greatly reduced former consumer and agricultural uses.
When freshly exposed to air, thallium exhibits a metallic luster, but soon develops a bluish-gray tinge, resembling lead in appearance. A heavy oxide builds up on thallium if left in air, and in the presence of water the hydride is formed. The metal is very soft and malleable. It can be cut with a knife. Twenty five isotopic forms of thallium, with atomic masses ranging from 184 to 210 are recognized. Natural thallium is a mixture of two isotopes. A mercury-thallium alloy, which forms a eutectic at 8.5% thallium, is reported to freeze at -60C, some 20 degrees below the freezing point of mercury.
The name derives from the Greek thallos for "green shoot" or "twig" because of the bright green line in its spectrum. Thallium was discovered by the English physicist and chemist William Crookes in 1861. Metallic thallium was first isolated by the French chemist Claude-Auguste Lamy in 1862.
Thallium was discovered spectroscopically by Sir William Crookes, an English chemist, in 1861. Crooks had obtained the sludge left over from the production of sulfuric acid (H2SO4) from a friend. After removing all of the selenium from the sludge, he inspected it with a device known as a spectroscope to look for signs of tellurium. Rather than seeing the yellow spectral lines produced by tellurium, he observed a bright green line that no one had ever seen before. He named the new element that was producing the green line thallium, after the greek word for 'green twig', thallos. He isolated samples of thallium the next year. Thallium is found in the minerals crooksite (CuThSe), lorandite (TlAsS2) and hutchinsonite ((Pb, Tl)2As5S9), but is usually obtained as a byproduct of the production of sulfuric acid or as a byproduct of refining zinc or lead.
From Greek thallos, meanin a green shoot or twig. Thallium was discovered spectroscopically in 1861 by Crookes. The element was named after the beautiful green spectral line, which identified the element. The metal was isolated both by Crookes and by Lamy in 1862 at about the same time.
Pure thallium is a very soft, heavy metal with a fresh silvery luster. It tarnishes readily in air, developing a dull gray oxide coating. It is malleable enough to be cut with a knife and has a relatively low melting point for a metal.
Current uses are limited by toxicity and regulation. Thallium is used in some specialty infrared optical materials, low-melting glasses, and semiconductor or detector research. Thallium-201 is an important medical radioisotope for diagnostic imaging of cardiac perfusion. Historical uses included rodenticides, insecticides, and depilatory agents, but these were abandoned or tightly restricted in many countries because of poisoning risks.
There are no uses for metallic thallium since pure thallium quickly combines with oxygen and water vapor from the atmosphere, forming a black, powdery substance. Thallium, used in conjunction with sulfur or selenium and arsenic, forms low melting glass. Thallium sulfate (Tl2SO4), an odorless, tasteless thallium compound, was once used as a rat and ant poison, although it has been banned from household use in the United States since 1974. Thallium sulfide (Tl2S), thallium iodide (TlI) and thallium bromide (TlBr) are all compounds used in devices to detect infrared radiation.
Thallium sulfate has been widely employed as a rodenticide and ant killer. It is odorless and tasteless, giving no warning of its presence. Its use, however, has been prohibited in the U.S. since 1975 as a household insecticide and rodenticide. The electrical conductivity of thallium sulfide changes with exposure to infrared light, and this compound is used in photocells. Thallium bromide-iodide crystals have been used as infrared optical materials. Thallium has been used, with sulfur or selenium and arsenic, to produce low melting glasses with become fluid between 125 and 150C. These glasses have properties at room temperatures similar to ordinary glasses and are said to be durable and insoluble in water. Thallium oxide has been used to produce glasses with a high index of refraction, and is used in the manufacture of photo cells. Thallium has been used in treating ringworm and other skin infections; however, its use has been limited because of the narrow margin between toxicity and therapeutic benefits.
Isotopes in Earth/Planetary Science
Because molecules, atoms, and ions of the stable isotopes of thallium possess slightly different physical and chemical properties, they commonly will be fractionated during physical, chemical, and biological processes, giving rise to variations in isotopic abundances and in atomic weights. There are substantial variations in the isotopic abundances of thallium in natural terrestrial materials (Fig. IUPAC.81.1). These variations are useful in investigating the origin of substances and studying environmental, hydrological, and geological processes [538] M. Rehkamper, M. Frank, J. R. Hein, D. Porcelli, A. Halliday, J. Ingri, V. Liebetrau. Earth. Planet. Sci. Lett.197, 65 (2002).. The isotope-amount ratio n(205Tl)/n(203Tl) has been used to study how trace metals are transported and distributed in hydrothermal fluids [538] M. Rehkamper, M. Frank, J. R. Hein, D. Porcelli, A. Halliday, J. Ingri, V. Liebetrau. Earth. Planet. Sci. Lett.197, 65 (2002).. The n(205Tl)/n(203Tl) ratio has also been used to study the cycling, distribution, and behavior of thallium in the marine environment [538] M. Rehkamper, M. Frank, J. R. Hein, D. Porcelli, A. Halliday, J. Ingri, V. Liebetrau. Earth. Planet. Sci. Lett.197, 65 (2002)..
Isotopes in Medicine
201Tl scintigraphy is used to detect coronary artery disease [539] G. A. Beller, B. L. Zaret. Circulation101, 1465 (2000).. Imaging of 201Tl (with a half-life of 3 days), can be used for exercise perfusion tests of the myocardium (muscular tissue of the heart), which determine damage to the heart caused by a heart attack or by heart disease (Fig. IUPAC.81.2) [539] G. A. Beller, B. L. Zaret. Circulation101, 1465 (2000)..
Isotopes Used as a Source of Radioactive Isotope(s)
203Tl is used in the production of 201Tl via the 203Tl (p, 3 n) 201Pb reaction, which is followed by a subsequent electron capture decay reaction of 201Pb to finally yield 201Tl. 205Tl is used as an alternative target in the production of 201Tl.
Thallium chemistry is dominated by thallium(I), Tl⁺, and thallium(III), Tl³⁺, with Tl⁺ usually more stable in aqueous and many solid-state compounds. Representative thallium(I) compounds include thallium(I) sulfate, Tl₂SO₄, thallium(I) nitrate, TlNO₃, and thallium(I) chloride, TlCl. Thallium(III) oxide, Tl₂O₃, and thallium(III) chloride, TlCl₃, are stronger oxidizing or less stable species. Mixed thallium compounds occur in chalcogenide and halide materials used for optical and electronic studies.
See more information at the Thallium compound page.
Thallium and soluble thallium compounds are highly toxic by ingestion, inhalation, or skin exposure. Tl⁺ can interfere with potassium-dependent biological processes, and poisoning may have delayed neurological, gastrointestinal, and hair-loss symptoms. Dusts, fumes, and soluble salts are the main occupational hazards. Radioisotopes such as thallium-201 add external and internal radiation hazards that are isotope- and activity-dependent.
The element and its compounds are toxic and should be handled carefully. Contact of the metal with skin is dangerous, and when melting the metal adequate ventilation should be provided. Exposure to thallium (soluble compounds) - skin, as Tl, should not exceed 0.1 mg/m3 (8-hour time-weighted average - 40-hour work week). Thallium is suspected of carcinogenic potential for man.
Thallium occurs naturally at low concentrations, commonly associated with potassium minerals, sulfide ores, and some coals. Mining, smelting, cement production, and coal combustion can mobilize it locally. In the environment, Tl⁺ is relatively mobile in some waters and can be taken up by plants because of its chemical similarity to K⁺. It has no known beneficial biological role and can be a concern near contaminated industrial sites.
Thallium is not mined as a primary product. It is recovered mainly from flue dusts, residues, and by-product streams generated during refining of zinc, lead, copper, and other sulfide ores. Demand is small and specialized, with toxicity limiting broader applications and encouraging substitution. Supply can therefore depend more on base-metal processing practices, regulatory controls, and purification capacity than on dedicated thallium mining. Recycling is limited to particular industrial or research materials.
Thallium occurs in crooksite, lorandite, and hutchinsonite. It is also present in pyrites and is recovered from the roasting of this ore in connection with the production of sulfuric acid. It is also obtained from the smelting of lead and zinc ores. Extraction is somewhat complex and depends on the source of the thallium. Manganese nodules, found on the ocean floor, contain thallium.
Thallium is a heavy, rare element in cosmic terms. Its stable isotopes, ²⁰³Tl and ²⁰⁵Tl, are produced by neutron-capture processes in earlier generations of stars, with contributions from both slow and rapid neutron-capture pathways. It is not a major rock-forming element, but on planets it can concentrate in sulfide phases and volatile-rich geochemical reservoirs.
- Thallium was discovered by its bright green spectral line, which inspired its name from the Greek word for a green shoot
- Fresh thallium can be cut easily, but the exposed surface dulls quickly in air
- Tl⁺ is close enough in behavior to K⁺ to enter some biological potassium pathways
- Thallium(I) sulfate, Tl₂SO₄, was once used as a rodenticide before its toxicity led to severe restrictions
- Natural thallium consists chiefly of two stable isotopes, ²⁰³Tl and ²⁰⁵Tl
Images
Propriétés
Propriétés physiques
- Rayon atomique (empirique)
- 190 pm Comparer : Rayon atomique (empirique) de tous les éléments →
- Rayon covalent
- 145 pm Comparer : Rayon covalent de tous les éléments →
- Rayon de van der Waals
- 196 pm Comparer : Rayon de van der Waals de tous les éléments →
- Rayon métallique
- 144 pm Comparer : Rayon métallique de tous les éléments →
- Masse volumique
- 1,18 × 104 kg/m³ Comparer : Masse volumique de tous les éléments →
- Volume molaire
- 0,0172 L/mol
- Phase aux CNTP
- Solide Comparer : Phase aux CNTP de tous les éléments →
- Point de fusion
- 303,85 °C Comparer : Point de fusion de tous les éléments →
- Point d’ébullition
- 1472,85 °C Comparer : Point d’ébullition de tous les éléments →
- Conductivité thermique
- 46,1 W/(m·K) Comparer : Conductivité thermique de tous les éléments →
- Capacité thermique massique
- 0,129 J/(g·K) Comparer : Capacité thermique massique de tous les éléments →
- Capacité thermique molaire
- 26,32 J/(mol·K) Comparer : Capacité thermique molaire de tous les éléments →
- Structure cristalline
- Hexagonal compact Comparer : Structure cristalline de tous les éléments →
Propriétés chimiques
- Électronégativité (Pauling)
- 1,62 Comparer : Électronégativité (Pauling) de tous les éléments →
- Électronégativité (Allen)
- 1,789
- Affinité électronique
- 0,377 eV
- Énergie d’ionisation (1re)
- 6,108287 eV Comparer : Énergie d’ionisation (1re) de tous les éléments →
- Énergie d’ionisation (2e)
- 20,42837 eV Comparer : Énergie d’ionisation (2e) de tous les éléments →
- Énergie d’ionisation (3e)
- 29,852103 eV Comparer : Énergie d’ionisation (3e) de tous les éléments →
- Énergie d’ionisation (4e)
- 51,140176 eV Comparer : Énergie d’ionisation (4e) de tous les éléments →
- Énergie d’ionisation (5e)
- 62,600215 eV Comparer : Énergie d’ionisation (5e) de tous les éléments →
- États d’oxydation
- −5, −2, −1, +1, +2, +3 Comparer : États d’oxydation de tous les éléments →
- Électrons de valence
- 3 Comparer : Électrons de valence de tous les éléments →
- Configuration électronique
- [Xe] 6s2 4f14 5d10 6p1
Propriétés thermodynamiques
- Enthalpie de fusion
- 0,04290822 eV Comparer : Enthalpie de fusion de tous les éléments →
- Enthalpie de vaporisation
- 1,71011 eV Comparer : Enthalpie de vaporisation de tous les éléments →
- Enthalpie de sublimation
- 1,888376 eV
- Enthalpie d’atomisation
- 1,888376 eV
- Enthalpie d’atomisation
- 1,888376 eV
Propriétés nucléaires
- Protons
- 81 Comparer : Protons de tous les éléments →
- Neutrons
- 124 Comparer : Neutrons de tous les éléments →
- Isotopes connus
- 43 Comparer : Isotopes connus de tous les éléments →
- Isotopes stables
- 2 Comparer : Isotopes stables de tous les éléments →
- Isotope le plus stable
- Tl-205
- Année de découverte
- 1861
Abondance
- Abondance (croûte terrestre)
- 0,85 mg/kg Comparer : Abondance (croûte terrestre) de tous les éléments →
- Abondance (océan)
- 1,9 × 10−5 mg/L Comparer : Abondance (océan) de tous les éléments →
Structure cristalline
- Paramètre de maille a
- 346 pm
Structure électronique
- Électrons par couche
- 2, 8, 18, 32, 18, 3 Comparer : Électrons par couche de tous les éléments →
Identifiants
- Numéro CAS
- 7440-28-0 Comparer : Numéro CAS de tous les éléments →
- Symbole de terme
- 2P°1/2
- InChI
- InChI=1S/Tl
- Clé InChI
- BKVIYDNLLOSFOA-UHFFFAOYSA-N
Configuration électronique Mesuré
Tl: 4f¹⁴ 5d¹⁰ 6s² 6p¹[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p¹1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p¹Modèle atomique
Les isotopes diffèrent par leur nombre de neutrons, leur masse et leur stabilité — pas par la configuration électronique de l’atome neutre.
Modèle atomique schématique, non à l’échelle.
Empreinte atomique
Spectre d’émission / d’absorption
Distribution isotopique
| Nombre de masse | Masse atomique (u) | Abondance naturelle | Demi-vie |
|---|---|---|---|
| 203 Stable | 202,9723446 ± 0,0000014 | 29,5200% | Stable |
| 205 Stable | 204,9744278 ± 0,0000014 | 70,4800% | Stable |
Phase / État
Explication: 278,9 °C en dessous du point de fusion (303,85 °C)
Schématique, non à l’échelle
Points de transition de phase
Énergies de transition
Énergie nécessaire pour faire fondre 1 mol au point de fusion
Énergie nécessaire pour vaporiser 1 mol au point d’ébullition
Énergie nécessaire pour sublimer 1 mol au point de sublimation
Masse volumique
Dans les conditions standard
Dans les conditions standard
Spectres atomiques
Affichage de 10 sur 81. Tri par charge ionique croissante.
Raies répertoriées ?
| Ion | Charge | Nombre total de raies | Probabilités de transition | Désignations des niveaux |
|---|---|---|---|---|
| Tl I | 0 | 65 | 25 | 11 |
| Tl II | +1 | 82 | 3 | 7 |
| Tl III | +2 | 22 | 0 | 0 |
| Tl IV | +3 | 35 | 0 | 0 |
Niveaux répertoriés ?
| Ion | Charge | Niveaux |
|---|---|---|
| Tl I | 0 | 70 |
| Tl II | +1 | 82 |
| Tl III | +2 | 109 |
| Tl IV | +3 | 44 |
| Tl V | +4 | 2 |
| Tl VI | +5 | 2 |
| Tl VII | +6 | 2 |
| Tl VIII | +7 | 2 |
| Tl IX | +8 | 2 |
| Tl X | +9 | 2 |
Rayons ioniques
| Charge | Coordinence | Spin | Rayon |
|---|---|---|---|
| +1 | 6 | N/D | 150 pm |
| +1 | 8 | N/D | 159 pm |
| +1 | 12 | N/D | 170 pm |
| +3 | 4 | N/D | 75 pm |
| +3 | 6 | N/D | 88.5 pm |
| +3 | 8 | N/D | 98 pm |
Composés
Isotopes (2)
| Nombre de masse | Masse atomique (u) | Abondance naturelle | Demi-vie | Mode de désintégration | |
|---|---|---|---|---|---|
| 203 Stable | 202,9723446 ± 0,0000014 | 29,5200% ± 0,0100% | Stable | stable | |
| 205 Stable | 204,9744278 ± 0,0000014 | 70,4800% ± 0,0100% | Stable | stable |
Propriétés étendues
Rayons covalents (données étendues)
- Rayon covalent (Pyykkö)
- 144 pm
- Rayon covalent (Pyykkö, liaison double)
- 142 pm
- Rayon covalent (Pyykkö, liaison triple)
- 150 pm
- Rayon covalent (Bragg)
- 190 pm
Rayons de van der Waals
- Bondi
- 196 pm
- Batsanov
- 220 pm
- Alvarez
- 247 pm
- UFF
- 434,7 pm
- MM3
- 259 pm
Rayons atomiques et métalliques
- Rayon atomique (Rahm)
- 242 pm
- Rayon métallique (C12)
- 160 pm
Échelles de numérotation
- Mendeleev
- 85
- Pettifor
- 78
- Glawe
- 81
Échelles d’électronégativité
- Ghosh
- 0
- Miedema
- 4
- Gunnarsson–Lundqvist
- 3
- Robles–Bartolotti
- 2
Polarisabilité et dispersion
- Polarisabilité dipolaire
- 50 a.u.
- Polarisabilité dipolaire (incertitude)
- 2 a.u.
- C₆ (Gould–Bučko)
- 509 Ha·Bohr6
Paramètres de Miedema
- Volume molaire de Miedema
- 17,23 cm3/mol
- Densité électronique de Miedema
- 1
Transitions de phase et allotropes
| Point de fusion | 577,15 K |
| Point d’ébullition | 1746,15 K |
Catégories d’états d’oxydation
Données de référence avancées
Constantes d’écran (15)
| n | Orbitale | σ |
|---|---|---|
| 1 | s | 1,5591 |
| 2 | p | 4,5138 |
| 2 | s | 21,3158 |
| 3 | d | 13,4658 |
| 3 | p | 22,6335 |
| 3 | s | 23,5809 |
| 4 | d | 37,6112 |
| 4 | f | 38,1324 |
| 4 | p | 35,7832 |
| 4 | s | 34,9212 |
Détail des rayons cristallins (6)
| Charge | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 1 | VI | 164 | from r^3 vs V plots, | |
| 1 | VIII | 173 | from r^3 vs V plots, | |
| 1 | XII | 184 | from r^3 vs V plots, estimated, | |
| 3 | IV | 89 | ||
| 3 | VI | 102,5 | from r^3 vs V plots, | |
| 3 | VIII | 112 | calculated, |
Modes de désintégration des isotopes (69)
| Isotope | Mode | Intensité |
|---|---|---|
| 176 | p | 100% |
| 176 | A | — |
| 176 | B+ | — |
| 177 | A | 73% |
| 177 | p | — |
| 178 | A | 62% |
| 178 | B+ | 38% |
| 178 | B+SF | 0,1% |
| 179 | A | 60% |
| 179 | B+ | — |
Facteurs de diffusion des rayons X (516)
| Énergie (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 1,80392 |
| 10,1617 | — | 1,75555 |
| 10,3261 | — | 1,69589 |
| 10,4931 | — | 1,59546 |
| 10,6628 | — | 1,46625 |
| 10,8353 | — | 1,39341 |
| 11,0106 | — | 1,31349 |
| 11,1886 | — | 1,20783 |
| 11,3696 | — | 1,13261 |
| 11,5535 | — | 1,07387 |
Données complémentaires
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
8.5×10-1 milligrams per kilogram
Références (1)
- [5] Thallium https://education.jlab.org/itselemental/ele081.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
1.9×10-5 milligrams per liter
Références (1)
- [5] Thallium https://education.jlab.org/itselemental/ele081.html
Sources
Sources of this element.
Thallium occurs in crooksite, lorandite, and hutchinsonite. It is also present in pyrites and is recovered from the roasting of this ore in connection with the production of sulfuric acid. It is also obtained from the smelting of lead and zinc ores. Extraction is somewhat complex and depends on the source of the thallium. Manganese nodules, found on the ocean floor, contain thallium.
Références (1)
- [6] Thallium https://periodic.lanl.gov/81.shtml
Références
(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.
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This section provides all form of data related to element Thallium.
The element property data was retrieved from publications.