Holmium (Ho)
lanthanideSolid
Peso atomico standard
164,93033 uConfigurazione elettronica
[Xe] 6s2 4f11Punto di fusione
1473,85 °CPunto di ebollizione
2699,85 °CDensità
8800 kg/m³Stati di ossidazione
0, +1, +2, +3Elettronegatività (Pauling)
1,23Energia di ionizzazione (1ª)
6,0215 eVAnno della scoperta
1878Raggio atomico
175 pmDettagli
Holmium is a lanthanide metal and one of the heavy rare earth elements. In compounds it is almost always trivalent, forming Ho³⁺ salts with the pink, yellow, or pale colors typical of f-electron transitions. Natural holmium is monoisotopic, consisting essentially of stable ¹⁶⁵Ho. Its large magnetic moment gives the element and some of its compounds unusual magnetic behavior at low temperature.
Pure holmium has a metallic to bright silver luster. It is relatively soft and malleable and is stable in dry air at room temperature but rapidly oxidizes in moist air and at elevated temperatures. The metal has unusual magnetic properties. Few uses have yet been found for the element. The element, as with other rare earths, seems to have a low acute toxic rating.
The name derives from the Latin holmia for Stockholm. It was discovered in erbia earth by the Swiss chemist J. L. Soret in 1878, who referred to it as element X. It was later independently discovered by the Swedish chemist Per Theodor Cleve in 1879. It was first isolated in 1911 by Homberg, who proposed the name holmium either to recognize the discoverer Per Cleve, who was from Stockholm, or perhaps to establish his own name in history.
Holmium 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. Holmium's absorption spectrum was observed earlier that year by J. L. Soret and M. Delafontaine, Swiss chemists. Today, holmium 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 0.05% holmium. Holmium has no commercial applications, although it has unusual magnetic properties that could be exploited in the future.
Holmium forms no commercially important compounds. Some of holmium's compounds include: holmium oxide (Ho2O3), holmium fluoride (HoF3) and holmium iodide (HoI3).
From the Latin word Holmia meaning Stockholm. The special absorption bands of holmium were noticed in 1878 by the Swiss chemists Delafontaine and Soret, who announced the existence of an "Element X." Cleve, of Sweden, later independently discovered the element while working on erbia earth. The element is named after Cleve's native city. Holmia, the yellow oxide, was prepared by Homberg in 1911. Holmium occurs in gadolinite, monazite, and in other rare-earth minerals. It is commercially obtained from monazite, occurring in that mineral to the extent of about 0.05%. It has been isolated by the reduction of its anhydrous chloride or fluoride with calcium metal.
Pure holmium is a soft, silvery, metallic solid that can be cut and worked when freshly prepared. It tarnishes slowly in air and is more reactive as filings or powder. Like other lanthanides, it has a high melting point and a close-packed metallic structure under ordinary conditions.
Holmium has specialized uses rather than large-volume applications. Holmium-doped yttrium aluminium garnet, Y₃Al₅O₁₂, is used in solid-state lasers emitting near 2.1 micrometres, including surgical and materials-processing systems. Holmium oxide, Ho₂O₃, is used as a colorant for glass and cubic zirconia and as a wavelength calibration material in optical spectrophotometry. Metallic holmium and holmium-containing alloys are also used in magnetic research and in some high-field magnet pole pieces.
It has very few practical applications; however, it has some unusual magnetic properties that offer some hope for future applications.
Isotopes in Medicine
Radiosynovectomy with 166Ho-radiopharmaceutical agents can be used for treatment of arthritis. The half-life of 166Ho is 1.1 days. 166Ho ferric hydroxide macroaggregate ([ 166Ho] FHMA) radiosynovectomy is being used because FHMA minimizes extra-articular (outside a joint) leakage of the radioisotope [472] S. Zeisler, K. Weber. J. Radioanal. Nucl. Chem.227, 105 (1998)., [473] O. T. Mäkelä, M. J. Lammi, H. Uusitalo, M. M. Hyttinen, E. Vuorio, H. J. Helminen, R. M. Tulamo. Ann. Rheum. Dis.62, 43 (2003).. 166Ho has been used for radioimmunotherapy (RIT) with labeled antibodies [474] H. Mohsin, F. Jia, G. Sivaguru, M. J. Hudson, T. D. Shelton, T. J. Hoffman, C. S. Cutler, A. R. Ketring, P. S. Athey, J. Simon, R. K. Frank, S. S. Jurisson, M. R. Lewis. Bioconjugate Chem.17, 485 (2006).. The 166Ho-chitosan complex (a linear polysaccharide, which is a long-chain molecule like cellulose that is used by the body for energy storage) is being used for hepatic (liver) cancer therapy [475] M. L. Smits, J. F. Nijsen, M. A. van den Bosch, M. G. Lam, M. A. Vente, J. E. Huijbregts, A. D. van het Schip, M. Elschot, W. Bult, H. W. de Jong, P. C. Meulenhoff, B. A. Zonnenberg. J. Exp. Clin. Cancer Res.29, 70 (2010).. 166Ho-labeled radiopharmaceuticals have been used for alleviating pain from bone metastases [443] International Atomic Energy Agency. Optimization of Production and Quality Control of Therapeutic Radionuclides and Radiopharmaceuticals, IAEA-TECDOC-1114, IAEA VIENNA (1999)., [473] O. T. Mäkelä, M. J. Lammi, H. Uusitalo, M. M. Hyttinen, E. Vuorio, H. J. Helminen, R. M. Tulamo. Ann. Rheum. Dis.62, 43 (2003)., [476] F. Melichar, M. Kropacek, M. Mirzajevova. J. Label. Compd. Radiopharm.46 (S1), S303 (2003). https://onlinelibrary.wiley.com/doi/abs/10.1002/jlcr.772..
166Ho microspheres have been used for intra-arterial radioembolization (treatment where radioactive particles are delivered to a tumor through the bloodstream) of liver metastases (Fig. IUPAC.67.1) [475] M. L. Smits, J. F. Nijsen, M. A. van den Bosch, M. G. Lam, M. A. Vente, J. E. Huijbregts, A. D. van het Schip, M. Elschot, W. Bult, H. W. de Jong, P. C. Meulenhoff, B. A. Zonnenberg. J. Exp. Clin. Cancer Res.29, 70 (2010).. 166Ho is paramagnetic and emits both beta and gamma radiation, which makes it ideal for radioembolization. These properties also enable the distribution of 166Ho microspheres to be visualized with magnetic resonance imaging and single-photon emission computed tomography (SPECT) [475] M. L. Smits, J. F. Nijsen, M. A. van den Bosch, M. G. Lam, M. A. Vente, J. E. Huijbregts, A. D. van het Schip, M. Elschot, W. Bult, H. W. de Jong, P. C. Meulenhoff, B. A. Zonnenberg. J. Exp. Clin. Cancer Res.29, 70 (2010)..
The 166Ho-Patch is a specially designed radioactive skin patch that is used for external radiation of superficial skin cancers and Bowen’s disease in areas that are sensitive and difficult to treat by methods that are more destructive and have poor cosmetic results (i.e. areas of the face) [477] J. D. Lee, K. K. Park, M. G. Lee, E. H. Kim, K. J. Rhim, J. T. Lee, H. S. Yoo, Y. M. Kim, K. B. Park, J. R. Kim. J. Nucl. Med.38, 697 (1997)., [478] Y. L. Chung, J. D. Lee, D. Bang, J. B. Lee, K. B. Park, M. G. Lee. Eur. J. Nucl. Med. Mol. Imaging27, 842 (2000)..
Holmium chemistry is dominated by the +3 oxidation state. Holmium(III) oxide, Ho₂O₃, is the common oxide and is a starting material for many other salts. Holmium(III) chloride, HoCl₃, and holmium(III) nitrate, Ho(NO₃)₃, form hydrated salts that dissolve in water to give Ho³⁺ aquo complexes. The metal reacts with halogens to form trihalides and with acids to produce salts while evolving H₂. Lower oxidation states are not important in ordinary aqueous or solid-state chemistry.
See more information at the Holmium compound page.
Bulk holmium metal has low acute toxicity compared with many industrial metals, but powders and turnings are flammable and can irritate skin, eyes, and lungs. Soluble holmium salts should be handled as toxicologically insufficiently characterized rare-earth compounds. Natural holmium is stable and not a radiological hazard, although neutron activation can produce radioactive isotopes for research or medical studies.
Holmium occurs dispersed in rare-earth minerals such as monazite and xenotime, not as native metal. In weathering environments it behaves like other trivalent lanthanides, tending to bind to phosphates, carbonates, oxides, and clay surfaces rather than remaining highly mobile as a free ion. It has no known essential biological role, and environmental concentrations are normally very low except near rare-earth mining, processing, or waste streams.
Holmium is obtained as a minor by-product of rare-earth extraction, especially from heavy-rare-earth concentrates derived from ion-adsorption clays, xenotime, and some monazite sources. Separation depends on solvent extraction or ion-exchange methods because adjacent lanthanides have very similar chemistry. Demand is small and specialized, so supply is tied to broader rare-earth processing capacity rather than to dedicated holmium mining. Recycling is limited because most uses contain small dispersed amounts.
Occurs in gadolinite. Most often from monazite which is often 50% rare earth and typically 0.05% holmium.
Holmium is a rare cosmic element. Its stable isotope is produced mainly by slow and rapid neutron-capture processes in evolved stars and explosive stellar events, followed by radioactive decay chains that end at stable nuclei. In the Solar System it is concentrated with other refractory lithophile rare earths in rocky material and is depleted in volatile-rich reservoirs only by dilution, not by volatility.
- Holmium has one of the largest magnetic moments of any naturally occurring element.
- Its name comes from Holmia, the Latin name for Stockholm.
- Natural holmium is essentially all ¹⁶⁵Ho.
- Holmium oxide solutions and glasses give sharp optical absorption bands useful for calibration.
- The element was identified spectroscopically before it was isolated in relatively pure form.
Immagini
Proprietà
Fisiche
- Raggio atomico (empirico)
- 175 pm Confronta Raggio atomico (empirico) di tutti gli elementi →
- Raggio covalente
- 192 pm Confronta Raggio covalente di tutti gli elementi →
- Raggio di van der Waals
- 216 pm Confronta Raggio di van der Waals di tutti gli elementi →
- Densità
- 8800 kg/m³ Confronta Densità di tutti gli elementi →
- Volume molare
- 0,0187 L/mol
- Fase in condizioni STP
- Solido Confronta Fase in condizioni STP di tutti gli elementi →
- Punto di fusione
- 1473,85 °C Confronta Punto di fusione di tutti gli elementi →
- Punto di ebollizione
- 2699,85 °C Confronta Punto di ebollizione di tutti gli elementi →
- Capacità termica specifica
- 0,165 J/(g·K) Confronta Capacità termica specifica di tutti gli elementi →
- Capacità termica molare
- 27,15 J/(mol·K) Confronta Capacità termica molare di tutti gli elementi →
- Struttura cristallina
- Esagonale compatta Confronta Struttura cristallina di tutti gli elementi →
Chimiche
- Elettronegatività (Pauling)
- 1,23 Confronta Elettronegatività (Pauling) di tutti gli elementi →
- Affinità elettronica
- 0,338 eV
- Energia di ionizzazione (1ª)
- 6,0215 eV Confronta Energia di ionizzazione (1ª) di tutti gli elementi →
- Energia di ionizzazione (2ª)
- 11,781041 eV Confronta Energia di ionizzazione (2ª) di tutti gli elementi →
- Energia di ionizzazione (3ª)
- 22,790078 eV Confronta Energia di ionizzazione (3ª) di tutti gli elementi →
- Energia di ionizzazione (4ª)
- 42,520146 eV Confronta Energia di ionizzazione (4ª) di tutti gli elementi →
- Energia di ionizzazione (5ª)
- 63,90022 eV Confronta Energia di ionizzazione (5ª) di tutti gli elementi →
- Stati di ossidazione
- 0, +1, +2, +3 Confronta Stati di ossidazione di tutti gli elementi →
- Elettroni di valenza
- 3 Confronta Elettroni di valenza di tutti gli elementi →
- Configurazione elettronica
- [Xe] 6s2 4f11
Termodinamiche
- Calore di fusione
- 0,11608022 eV Confronta Calore di fusione di tutti gli elementi →
- Calore di vaporizzazione
- 2,591076 eV Confronta Calore di vaporizzazione di tutti gli elementi →
- Calore di sublimazione
- 3,119656 eV
- Calore di atomizzazione
- 3,119656 eV
- Entalpia di atomizzazione
- 3,11551 eV
Nucleari
- Protoni
- 67 Confronta Protoni di tutti gli elementi →
- Neutroni
- 98 Confronta Neutroni di tutti gli elementi →
- Isotopi noti
- 39 Confronta Isotopi noti di tutti gli elementi →
- Isotopi stabili
- 1 Confronta Isotopi stabili di tutti gli elementi →
- Isotopo più stabile
- Ho-165
- Anno della scoperta
- 1878
Abbondanza
- Abbondanza (crosta terrestre)
- 1,3 mg/kg Confronta Abbondanza (crosta terrestre) di tutti gli elementi →
- Abbondanza (oceano)
- 2,2 × 10−7 mg/L Confronta Abbondanza (oceano) di tutti gli elementi →
Struttura cristallina
- Costante reticolare a
- 358 pm
Struttura elettronica
- Elettroni per guscio
- 2, 8, 18, 29, 8, 2 Confronta Elettroni per guscio di tutti gli elementi →
Identificativi
- Numero CAS
- 7440-60-0 Confronta Numero CAS di tutti gli elementi →
- Simbolo di termine
- 4I°15/2
- InChI
- InChI=1S/Ho
- Chiave InChI
- KJZYNXUDTRRSPN-UHFFFAOYSA-N
Configurazione elettronica Misurato
Ho: 4f¹¹ 6s²[Xe] 4f¹¹ 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹¹ 6s²Modello atomico
Gli isotopi modificano il numero di neutroni, la massa e la stabilità — non la configurazione elettronica di un atomo neutro.
Modello atomico schematico, non in scala.
Impronta atomica
Spettro di emissione / assorbimento
Distribuzione isotopica
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita |
|---|---|---|---|
| 165 Stabile | 164,9303288 ± 0,0000021 | 100,0000% | Stabile |
Fase / Stato
Motivo: 1448,8 °C sotto il punto di fusione (1473,85 °C)
Schema non in scala
Punti di transizione di fase
Energie di transizione
Energia necessaria per fondere 1 mol al punto di fusione
Energia necessaria per vaporizzare 1 mol al punto di ebollizione
Energia necessaria per sublimare 1 mol al punto di sublimazione
Densità
In condizioni standard
In condizioni standard
Spettri atomici
Sono visualizzati 10 di 67. Ordinamento per carica ionica crescente.
Righe disponibili ?
| Ione | Carica | Righe totali | Probabilità di transizione | Designazioni dei livelli |
|---|---|---|---|---|
| Ho I | 0 | 282 | 13 | 13 |
| Ho II | +1 | 284 | 4 | 12 |
Livelli disponibili ?
| Ione | Carica | Livelli |
|---|---|---|
| Ho I | 0 | 234 |
| Ho II | +1 | 55 |
| Ho III | +2 | 126 |
| Ho IV | +3 | 21 |
| Ho V | +4 | 2 |
| Ho VI | +5 | 2 |
| Ho VII | +6 | 2 |
| Ho VIII | +7 | 2 |
| Ho IX | +8 | 2 |
| Ho X | +9 | 2 |
Raggi ionici
| Carica | Coordinazione | Spin | Raggio |
|---|---|---|---|
| +3 | 6 | N/D | 90.10000000000001 pm |
| +3 | 8 | N/D | 101.49999999999999 pm |
| +3 | 9 | N/D | 107.2 pm |
| +3 | 10 | N/D | 112.00000000000001 pm |
Composti
Isotopi (1)
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita | Modalità di decadimento | |
|---|---|---|---|---|---|
| 165 Stabile | 164,9303288 ± 0,0000021 | 100,0000% | Stabile | stable |
Proprietà estese
Raggi covalenti (dati estesi)
- Raggio covalente (Pyykkö)
- 166 pm
- Raggio covalente (Pyykkö, legame doppio)
- 133 pm
Raggi di van der Waals
- Alvarez
- 281 pm
- UFF
- 340,9 pm
- MM3
- 267 pm
Raggi atomici e metallici
- Raggio atomico (Rahm)
- 273 pm
Scale di numerazione
- Mendeleev
- 33
- Pettifor
- 24
- Glawe
- 23
Scale di elettronegatività
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 5
- Robles–Bartolotti
- 4
Polarizzabilità e dispersione
- Polarizzabilità dipolare
- 156 a.u.
- Polarizzabilità dipolare (inc.)
- 10 a.u.
- C₆ (Gould–Bučko)
- 2280 Ha·Bohr6
Parametri di Miedema
- Volume molare di Miedema
- 18,76 cm3/mol
- Densità elettronica di Miedema
- 2
Rischio di approvvigionamento ed economia
- Concentrazione della produzione
- 97
- Rischio relativo di approvvigionamento
- 10
- Distribuzione delle riserve
- 50
- Stabilità politica (principale produttore)
- 24
- Stabilità politica (principale detentore di riserve)
- 24
Transizioni di fase e allotropi
| Punto di fusione | 1745,15 K |
| Punto di ebollizione | 2973,15 K |
Categorie degli stati di ossidazione
Dati di riferimento avanzati
Costanti di schermaggio (13)
| n | Orbitale | σ |
|---|---|---|
| 1 | s | 1,3088 |
| 2 | p | 4,3332 |
| 2 | s | 17,5444 |
| 3 | d | 13,6531 |
| 3 | p | 20,2546 |
| 3 | s | 20,7649 |
| 4 | d | 35,3284 |
| 4 | f | 39,5304 |
| 4 | p | 32,4372 |
| 4 | s | 31,688 |
Dettaglio dei raggi cristallini (4)
| Carica | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 3 | VI | 104,1 | from r^3 vs V plots, | |
| 3 | VIII | 115,5 | from r^3 vs V plots, | |
| 3 | IX | 121,2 | from r^3 vs V plots, | |
| 3 | X | 126 |
Modalità di decadimento degli isotopi (57)
| Isotopo | Modalità | Intensità |
|---|---|---|
| 140 | p | — |
| 140 | B+ | — |
| 140 | B+p | — |
| 141 | p | 100% |
| 141 | B+ | — |
| 141 | B+p | — |
| 142 | B+ | 100% |
| 142 | B+p | — |
| 142 | p | 0% |
| 143 | B+ | — |
Fattori di diffusione dei raggi X (514)
| Energia (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0,16762 |
| 10,1617 | — | 0,17164 |
| 10,3261 | — | 0,17576 |
| 10,4931 | — | 0,17997 |
| 10,6628 | — | 0,18429 |
| 10,8353 | — | 0,1887 |
| 11,0106 | — | 0,19366 |
| 11,1886 | — | 0,20086 |
| 11,3696 | — | 0,20833 |
| 11,5535 | — | 0,21608 |
Dati aggiuntivi
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
1.3 milligrams per kilogram
Riferimenti (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
2.2×10-7 milligrams per liter
Riferimenti (1)
Riferimenti
(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 Holmium.
The element property data was retrieved from publications.