Thulium (Tm)
lanthanideSolid
Peso atómico estándar
168,93422 uConfiguración electrónica
[Xe] 6s2 4f13Punto de fusión
1544,85 °CPunto de ebullición
1949,85 °CDensidad
9320 kg/m³Estados de oxidación
0, +1, +2, +3Electronegatividad (Pauling)
1,25Energía de ionización (1.ª)
6,184402 eVAño de descubrimiento
1879Radio atómico
175 pmDetalles
Thulium is a lanthanide rare-earth metal and the least abundant stable lanthanide in Earth’s crust. It is chemically typical of the series, forming mainly Tm³⁺ compounds with a high affinity for oxygen and halogens. The element is not scarce enough to be unattainable, but it is dispersed and difficult to separate from neighboring lanthanides. Its technological importance is concentrated in isotope sources, specialty lasers, and optical materials rather than bulk structural use.
Thulium can be isolated by reduction of the oxide with lanthanum metal or by calcium reduction of a closed container. The element is silver-gray, soft, malleable, and ductile, and can be cut with a knife. Twenty five isotopes are known, with atomic masses ranging from 152 to 176. Natural thulium, which is 100% 169Tm, is stable.
The name derives from Thule, the earliest name for the northernmost part of the civilized world—Scandinavia. It was discovered in 1879 by the Swedish chemist Per Theodor Cleve in a sample of erbium mineral. Thulium was first isolated by the American chemist Charles James in 1911.
Thulium was discovered by Per Theodor Cleve, a Swedish chemist, in 1879. Cleve used the same method Carl Gustaf Mosander used to discover lanthanum, erbium and terbium, he looked for impurities in the oxides of other rare earth elements. He started with erbia, the oxide of erbium (Er2O3), and removed all of the known contaminants. After further processing, he obtained two new materials, one brown and the other green. Cleve named the brown material holmia and the green material thulia. Holmia is the oxide of the element holmium and thulia is the oxide of the element thulium. Today, thulium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements that can contain as much as 0.007% thulium.
Named after Thule, the earliest name for Scandinavia. Discovered in 1879 by Cleve. Thulium occurs in small quantities along with other rare earths in a number of minerals. It is obtained commercially from monazite, which contains about 0.007% of the element. Thulium is the least abundant of the rare earth elements, but with new sources recently discovered, it is now considered to be about as rare as silver,gold, or cadmium.
Pure thulium is a soft, malleable, silvery metal. It slowly tarnishes in air as oxide forms on the surface and reacts more readily when heated. Like many lanthanides, it can be cut with a knife and is normally stored to limit oxidation.
Thulium has specialized uses where its nuclear or optical properties are useful. Neutron-activated ¹⁷⁰Tm produces ¹⁷⁰Tm, a portable gamma and X-ray source formerly used in industrial radiography and still of technical interest where compact sealed sources are suitable. Thulium-doped yttrium aluminium garnet, commonly written Y₃Al₅O₁₂:Tm, and other host crystals are used in solid-state lasers near the two-micrometre infrared region. Thulium-doped silica fibers are also used in fiber lasers and amplifiers. Small amounts may be used in research alloys and magnetic studies, but there is no large-volume elemental application.
Thulium is the least abundant of the naturally occurring rare earth elements. Metallic thulium is relatively expensive and has only recently become available. It currently has no commercial applications, although one of its isotopes, thulium-169, could be used as a radiation source for portable X-ray machines.
Thulium forms no commercially important compounds. Some of thulium's compounds include: thulium oxide (Tm2O3), thulium fluoride (TmF3) and thulium iodide (TmI3).
Because of the relatively high price of the metal, thulium has not yet found many practical applications. 169Tm bombarded in a nuclear reactor can be used as a radiation source in portable X-ray equipment. 171Tm is potentially useful as an energy source. Natural thulium also has possible use in ferrites (ceramic magnetic materials) used in microwave equipment, and can be used for doping fiber lasers. As with other lanthanides, thulium has a low-to-moderate acute toxic rating. It should be handled with care.
Isotopes in Industry
170Tm (with a half-life of about 130 days) is used in the petrochemical industry for industrial radiography to test welds in pipes and tanks [486] Industrial Applications of Sealed Radiation Sources and Alternative Non Nuclear Technologies, Final Report, 68-D-00-210, p. 37. Trinity Engineering Associates Ohio (2002)..
Isotopes in Medicine
167Tm (with a half-life of 9.2 days) is useful for tumor and bone studies [487] F. Tárkányi, A. Hermanne, S. Takács, B. Király, I. Spahn, A. V. Ignatyuk. Appl. Radiat. Isot.68, 250 (2010).. Stable 169Tm can be bombarded in a nuclear reactor to create 170Tm, via the 169Tm (n, γ) 170Tm reaction, which emits X-rays and has been used in portable X-ray equipment as a radiation source [488] D. Granero, J. Pérez-Calatayud, F. Ballester, A. J. Bos, J. Venselaar. Radiat. Prot. Dosimetry118, 11 (2006).. 170Tm has been used in high-dose-rate (HDR) brachytherapy [489] F. Ballester, D. Granero, J. Perez-Calatayud, J. L. Venselaar, M. J. Rivard. Med. Phys.37, 1629 (2010). and for use in radiosynovectomy of medium sized joints (Fig. IUPAC.69.1) [490] A. Polyak, T. Das, S. Chakraborty, R. Kiraly, G. Dabasi, R. P. Joba, C. Jakab, J. Thuroczy, Z. Postenyi, V. Haasz, G. Janoki, G. A. Janoki, M. R. A. Pillai, L. Balogh. Cancer Biother. Radiopharm.29, 330 (2014)..
Thulium chemistry is dominated by the +3 oxidation state. Thulium(III) oxide, Tm₂O₃, is the common oxide and is a useful starting material for preparing other salts and optical ceramics. Thulium(III) chloride, TmCl₃, and thulium(III) fluoride, TmF₃, are representative halides; the fluoride is sparingly soluble and useful in separations and fluoride materials. A +2 state is known in some strongly reducing solid compounds, but it is much less stable than Tm³⁺ in ordinary aqueous chemistry. In solution, Tm³⁺ salts are typically pale green to nearly colorless depending on concentration and ligand field.
See more information at the Thulium compound page.
Metallic thulium has low acute chemical toxicity compared with many heavy metals, but fine powder is a fire hazard and can react with air or moisture. Soluble thulium salts should be handled as toxic laboratory chemicals because rare-earth ions can affect biological processes at elevated exposure. Radioactive ¹⁷⁰Tm presents an external radiation hazard and an internal hazard if contamination occurs; sealed sources require isotope-specific controls.
Thulium occurs naturally only as a minor constituent of rare-earth minerals, especially minerals that contain the heavy lanthanides. Weathering releases it mainly as Tm³⁺, which tends to bind to clays, oxides, phosphates, and organic matter rather than remain highly mobile. It has no known biological role. Environmental concentrations are usually very low, so ecological effects are mainly a concern near rare-earth mining, processing, or disposal sites.
Thulium is obtained as a by-product of rare-earth extraction rather than mined for its own sake. Sources include ion-adsorption clays and minerals such as monazite and xenotime that contain small fractions of heavy rare earths. Separation relies on solvent extraction, ion exchange, and conversion through oxide or salt intermediates, with cost driven more by separation complexity than by absolute crustal scarcity. Demand is small and specialized, so supply is tied to broader rare-earth processing rather than an independent commodity chain. Recycling is limited because applications use small amounts in dispersed devices or sealed sources.
Found with other rare earths in the minerals gadolinite, euxenite, xenotime, and monazite. Monazite is often 50% rare earth by weight and 0.007% thulium.
Thulium is a rare cosmic element produced mainly by neutron-capture processes in evolved stars and stellar explosions. Its odd atomic number and position among the heavy lanthanides make it much less abundant than lighter rock-forming elements and less abundant than several neighboring rare earths. In planets and meteorites it follows refractory lithophile behavior and partitions with other rare-earth elements rather than forming native metal.
- Thulium is the least abundant lanthanide that has a stable isotope.
- Natural thulium is essentially all ¹⁶⁹Tm.
- ¹⁷⁰Tm can be made by neutron irradiation of ¹⁶⁹Tm.
- Thulium was named after Thule, a classical name associated with the far north.
- Despite its rarity among lanthanides, thulium is more abundant in Earth’s crust than silver.
Imágenes
Propiedades
Físicas
- Radio atómico (empírico)
- 175 pm Comparar Radio atómico (empírico) de todos los elementos →
- Radio covalente
- 190 pm Comparar Radio covalente de todos los elementos →
- Radio de van der Waals
- 227 pm Comparar Radio de van der Waals de todos los elementos →
- Densidad
- 9320 kg/m³ Comparar Densidad de todos los elementos →
- Volumen molar
- 0,0181 L/mol
- Fase en CNPT
- Sólido Comparar Fase en CNPT de todos los elementos →
- Punto de fusión
- 1544,85 °C Comparar Punto de fusión de todos los elementos →
- Punto de ebullición
- 1949,85 °C Comparar Punto de ebullición de todos los elementos →
- Capacidad calorífica específica
- 0,16 J/(g·K) Comparar Capacidad calorífica específica de todos los elementos →
- Capacidad calorífica molar
- 27,03 J/(mol·K) Comparar Capacidad calorífica molar de todos los elementos →
- Estructura cristalina
- Hexagonal compacta Comparar Estructura cristalina de todos los elementos →
Químicas
- Electronegatividad (Pauling)
- 1,25 Comparar Electronegatividad (Pauling) de todos los elementos →
- Afinidad electrónica
- 1,029 eV
- Energía de ionización (1.ª)
- 6,184402 eV Comparar Energía de ionización (1.ª) de todos los elementos →
- Energía de ionización (2.ª)
- 12,065042 eV Comparar Energía de ionización (2.ª) de todos los elementos →
- Energía de ionización (3.ª)
- 23,660081 eV Comparar Energía de ionización (3.ª) de todos los elementos →
- Energía de ionización (4.ª)
- 42,410146 eV Comparar Energía de ionización (4.ª) de todos los elementos →
- Energía de ionización (5.ª)
- 65,400225 eV Comparar Energía de ionización (5.ª) de todos los elementos →
- Estados de oxidación
- 0, +1, +2, +3 Comparar Estados de oxidación de todos los elementos →
- Electrones de valencia
- 3 Comparar Electrones de valencia de todos los elementos →
- Configuración electrónica
- [Xe] 6s2 4f13
Termodinámicas
- Calor de fusión
- 0,12437166 eV Comparar Calor de fusión de todos los elementos →
- Calor de vaporización
- 1,979582 eV Comparar Calor de vaporización de todos los elementos →
- Calor de sublimación
- 2,404519 eV
- Calor de atomización
- 2,404519 eV
- Entalpía de atomización
- 2,406592 eV
Nucleares
- Protones
- 69 Comparar Protones de todos los elementos →
- Neutrones
- 100 Comparar Neutrones de todos los elementos →
- Isótopos conocidos
- 39 Comparar Isótopos conocidos de todos los elementos →
- Isótopos estables
- 1 Comparar Isótopos estables de todos los elementos →
- Isótopo más estable
- Tm-169
- Año de descubrimiento
- 1879
Abundancia
- Abundancia (corteza terrestre)
- 0,52 mg/kg Comparar Abundancia (corteza terrestre) de todos los elementos →
- Abundancia (océano)
- 1,7 × 10−7 mg/L Comparar Abundancia (océano) de todos los elementos →
Estructura cristalina
- Constante de red a
- 354 pm
Estructura electrónica
- Electrones por capa
- 2, 8, 18, 31, 8, 2 Comparar Electrones por capa de todos los elementos →
Identificadores
- Número CAS
- 7440-30-4 Comparar Número CAS de todos los elementos →
- Símbolo del término
- 2F°7/2
- InChI
- InChI=1S/Tm
- Clave InChI
- FRNOGLGSGLTDKL-UHFFFAOYSA-N
Configuración electrónica Medido
Tm: 4f¹³ 6s²[Xe] 4f¹³ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹³ 6s²Modelo atómico
Los isótopos cambian el número de neutrones, la masa y la estabilidad, pero no la configuración electrónica de un átomo neutro.
Modelo atómico esquemático, no a escala.
Huella atómica
Espectro de emisión / absorción
Distribución isotópica
| Número másico | Masa atómica (u) | Abundancia natural | Periodo de semidesintegración |
|---|---|---|---|
| 169 Estable | 168,9342179 ± 0,0000022 | 100,0000% | Estable |
Fase / Estado
Motivo: 1519,8 °C por debajo del punto de fusión (1544,85 °C)
Esquemático, no a escala
Puntos de transición de fase
Energías de transición
Energía necesaria para fundir 1 mol en el punto de fusión
Energía necesaria para vaporizar 1 mol en el punto de ebullición
Energía necesaria para sublimar 1 mol en el punto de sublimación
Densidad
En condiciones estándar
En condiciones estándar
Espectros atómicos
Se muestran 10 de 69. Ordenado por carga del ion (ascendente).
Líneas disponibles ?
| Ion | Carga | Total de líneas | Probabilidades de transición | Designaciones de los niveles |
|---|---|---|---|---|
| Tm I | 0 | 538 | 408 | 525 |
| Tm II | +1 | 267 | 13 | 13 |
| Tm III | +2 | 186 | 0 | 0 |
Niveles disponibles ?
| Ion | Carga | Niveles |
|---|---|---|
| Tm I | 0 | 631 |
| Tm II | +1 | 367 |
| Tm III | +2 | 128 |
| Tm IV | +3 | 8 |
| Tm V | +4 | 2 |
| Tm VI | +5 | 2 |
| Tm VII | +6 | 2 |
| Tm VIII | +7 | 2 |
| Tm IX | +8 | 2 |
| Tm X | +9 | 2 |
Radios iónicos
| Carga | Coordinación | Espín | Radio |
|---|---|---|---|
| +2 | 6 | N/D | 103 pm |
| +2 | 7 | N/D | 109.00000000000001 pm |
| +3 | 6 | N/D | 88 pm |
| +3 | 8 | N/D | 99.4 pm |
| +3 | 9 | N/D | 105.2 pm |
Compuestos
Isótopos (1)
| Número másico | Masa atómica (u) | Abundancia natural | Periodo de semidesintegración | Modo de desintegración | |
|---|---|---|---|---|---|
| 169 Estable | 168,9342179 ± 0,0000022 | 100,0000% | Estable | stable |
Propiedades ampliadas
Radios covalentes (ampliados)
- Radio covalente (Pyykkö)
- 164 pm
- Radio covalente (Pyykkö, enlace doble)
- 131 pm
Radios de van der Waals
- Alvarez
- 279 pm
- UFF
- 337,4 pm
- MM3
- 267 pm
Radios atómicos y metálicos
- Radio atómico (Rahm)
- 271 pm
Escalas de numeración
- Mendeleev
- 37
- Pettifor
- 22
- Glawe
- 20
Escalas de electronegatividad
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 6
- Robles–Bartolotti
- 5
Polarizabilidad y dispersión
- Polarizabilidad dipolar
- 144 a.u.
- Polarizabilidad dipolar (incert.)
- 15 a.u.
- C₆ (Gould–Bučko)
- 2020 Ha·Bohr6
Parámetros de Miedema
- Volumen molar de Miedema
- 18,12 cm3/mol
- Densidad electrónica de Miedema
- 2
Riesgo de suministro y economía
- Concentración de la producción
- 97
- Riesgo relativo de suministro
- 10
- Distribución de las reservas
- 50
- Estabilidad política (principal productor)
- 24
- Estabilidad política (país con mayores reservas)
- 24
Transiciones de fase y alótropos
| Punto de fusión | 1818,15 K |
| Punto de ebullición | 2223,15 K |
Categorías de estados de oxidación
Datos de referencia avanzados
Constantes de apantallamiento (13)
| n | Orbital | σ |
|---|---|---|
| 1 | s | 1,3437 |
| 2 | p | 4,3588 |
| 2 | s | 18,0522 |
| 3 | d | 13,6257 |
| 3 | p | 20,5239 |
| 3 | s | 21,0816 |
| 4 | d | 36,056 |
| 4 | f | 40,366 |
| 4 | p | 33,012 |
| 4 | s | 31,8624 |
Detalle de los radios cristalinos (5)
| Carga | CN | Espín | rcrystal (pm) | Origen |
|---|---|---|---|---|
| 2 | VI | 117 | ||
| 2 | VII | 123 | ||
| 3 | VI | 102 | from r^3 vs V plots, | |
| 3 | VIII | 113,4 | from r^3 vs V plots, | |
| 3 | IX | 119,2 | from r^3 vs V plots, |
Modos de desintegración de los isótopos (58)
| Isótopo | Modo | Intensidad |
|---|---|---|
| 144 | p | — |
| 144 | B+ | — |
| 145 | p | 100% |
| 146 | p | 100% |
| 146 | B+ | — |
| 146 | B+p | — |
| 147 | B+ | 85% |
| 147 | p | 15% |
| 148 | B+ | 100% |
| 148 | B+p | — |
Factores de dispersión de rayos X (514)
| Energía (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0,17918 |
| 10,1617 | — | 0,18356 |
| 10,3261 | — | 0,18805 |
| 10,4931 | — | 0,19265 |
| 10,6628 | — | 0,19737 |
| 10,8353 | — | 0,2022 |
| 11,0106 | — | 0,20714 |
| 11,1886 | — | 0,21221 |
| 11,3696 | — | 0,21741 |
| 11,5535 | — | 0,22273 |
Datos adicionales
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
5.2×10-1 milligrams per kilogram
Referencias (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
1.7×10-7 milligrams per liter
Referencias (1)
Referencias
(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.
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/
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 Thulium.
The element property data was retrieved from publications.