Technetium (Tc)
transition-metalSolid
Peso atomico standard
[98]Configurazione elettronica
[Kr] 5s2 4d5Punto di fusione
2156,85 °CPunto di ebollizione
4264,85 °CDensità
1,1e+4 kg/m³Stati di ossidazione
−3, −1, +1, +2, +3, +4, +5, +6, +7Elettronegatività (Pauling)
1,9Energia di ionizzazione (1ª)
7,11938 eVAnno della scoperta
1937Raggio atomico
135 pmDettagli
Technetium is a radioactive transition metal in group 7, between molybdenum and ruthenium. It was the first element discovered without a stable isotope. Only trace natural technetium occurs, mainly from spontaneous fission of uranium and from neutron capture processes; practical quantities are made artificially. Its chemistry resembles rhenium and manganese in several oxidation states, and the isotope ⁹⁹ᵐTc is central to diagnostic nuclear medicine.
Technetium is a silvery-gray metal that tarnishes slowly in moist air. The common oxidation states of technetium are +7, +5, and +4. Under oxidizing conditions technetium (VII) will exist as the pertechnetate ion, TcO4-. The chemistry of technetium is said to be similar to that of rhenium. Technetium dissolves in nitric acid, aqua regia, and concentrated sulfuric acid, but is not soluble in hydrochloric acid of any strength. The element is a remarkable corrosion inhibitor for steel. The metal is an excellent superconductor at 11K and below.
Technetium was the first artificially produced element. It was isolated by Carlo Perrier and Emilio Segrè in 1937. Technetium was created by bombarding molybdenum atoms with deuterons that had been accelerated by a device called a cyclotron. Today, technetium is produced by bombarding molybdenum-98 with neutrons. Molybdenum-98 becomes molybdenum-99 when it captures a neutron. Molybdenum-99, with a half-life of 65.94 hours, decays into technetium-99 through beta decay. While technetium has never been found to occur naturally on earth, its spectral lines have been observed in S-, M- and N-type stars.
Technetium's most stable isotope, technetium-98, has a half-life of about 4,200,000 years. It decays into ruthenium-98 through beta decay.
From the Greek word technetos, artificial. Element 43 was predicted on the basis of the periodic table, and was erroneously reported as having been discovered in 1925, at which time it was named masurium. The element was actually discovered by Perrier and Segre in Italy in 1937. It was also found in a sample of molybdenum sent by E. Lawrence that was bombarded by deuterons in the Berkeley cyclotron. Technetium was the first element to be produced artificially. Since its discovery, searches for the element in terrestrial material have been made. Finally in 1962, technetium-99 was isolated and identified in African pitchblende (a uranium rich ore) in extremely minute quantities as a spontaneous fission product of uranium-238 by B.T. Kenna and P.K. Kuroda. If it does exist, the concentration must be very small. Technetium has been found in the spectrum of S-, M-, and N-type stars, and its presence in stellar matter is leading to new theories of the production of heavy elements in the stars.
Macroscopic technetium metal is a silvery-gray, metallic solid when prepared in the laboratory. Because all isotopes are radioactive, specimens are handled as controlled radioactive materials rather than ordinary metal samples.
The most important use is isotope-specific: ⁹⁹ᵐTc is used as a short-lived gamma-emitting tracer in many diagnostic imaging procedures, usually bound in radiopharmaceutical complexes selected for particular organs or physiological processes. Longer-lived ⁹⁹Tc has been studied as a corrosion inhibitor for steel in closed systems, but its radioactivity and regulatory burden prevent ordinary industrial use. Other technetium isotopes and compounds are used mainly in chemical, nuclear, and tracer research.
Small amounts of technetium can retard the corrosion of steel, although this protection can only be applied to closed systems due to technetium's radioactivity. Technetium can also be used as a medical tracer and to calibrate particle detectors.
Isotopes in Medicine
99mTc is an isomer of 99Tc with a half-life of approximately 6 h that is used to label peptides for morphologic (the form and structure of an organism) and dynamic modeling of renal (kidney), hepatic (liver), bone, and cardiac imaging [320] U. Abram, R. Alberto. J. Braz. Chem. Soc.17, 1486 (2006)., [322] M. Pérez Díaz, J. Quevedo Garcia, O. Diaz Rizo, R. Dopico Hernandez, E. Estevez Aparicio, A. Viamonte Marin, O. Cabrera Gorrin. Alasbimn J.4 (16), (2002).. 99mTc radiopharmaceuticals absorb to a variety of tumors. These tumors can be imaged using single-photon emission computed tomography (SPECT) coupled with non-invasive computed tomography (CT scan), which provides a high level of functional and anatomical information in a three-dimensional image (Fig. IUPAC.43.1) [323] A. Ballard. Biomarkers Key to Drug Development: Imaging and Biomarkers Drive Drug Development Engineered for Personalized Medicine, Imaging Technology News (2014), Feb. 26; http://www.itnonline.com/article/biomarkers-key-drug-development., [324] P. Ghosh, M. Kelly. Expanding the Power of PET with 18F-Sodium Fluoride, Siemens Medical Solutions USA, Inc (2017), Feb. 26; https://usa.healthcare.siemens.com/siemens_hwem-hwem_ssxa_websites-context-root/wcm/idc/groups/public/@us/@imaging/@molecular/documents/mdaw/ndu0/∼edisp/white_paper10_sodium_fluoride-00309726.. Medronate is a radioactive pharmaceutical, which has been used to find, treat, or study certain diseases or body functions. 99mTc-labeled medronate (99mTc-MDP) is used in a diagnostic test to detect metastases from prostate, lung or thyroid cancer, making use of a gamma camera to record the distribution of 99mTc-MDP within the body. A two-dimensional image of the affected areas is produced.
Technetium shows rich redox chemistry, with common oxidation states including +7, +4, and lower states in coordination complexes. Pertechnetate, TcO₄⁻, contains technetium(VII) and is chemically analogous to perrhenate; sodium pertechnetate, NaTcO₄, is a key soluble form in radiochemistry. Technetium dioxide, TcO₂, contains technetium(IV) and is much less mobile in many reducing environments. Technetium forms halides, oxides, sulfides, and numerous complexes with phosphines, carbonyls, and biological ligands.
See more information at the Technetium compound page.
All technetium isotopes are radioactive, but hazards differ strongly by isotope, activity, chemical form, and route of exposure. ⁹⁹ᵐTc has a short half-life and is managed under medical radiation controls. ⁹⁹Tc is a long-lived beta emitter; ingestion or inhalation of soluble pertechnetate is a principal concern because it can distribute in body fluids. Metal dusts and contaminated laboratory surfaces require radiological containment and monitoring.
It is reported that mild carbon steels may be effectively protected by as little as 55 ppm of KTcO4 in aerated distilled water at temperatures up to 250°C. This corrosion protection is limited to closed systems, since technetium is radioative and must be confined. 98Tc has a specific activity of 6.2 x 108 Bq/g. Activity of this level must not be allowed to spread. 99Tc is a contamination hazard and should be handled in a glove box.
Natural technetium is extremely scarce and transient on geological scales. Environmental technetium of practical concern comes mainly from nuclear fission products in reactor fuel, reprocessing streams, waste, and fallout residues. Pertechnetate, TcO₄⁻, is soluble and relatively mobile under oxidizing conditions, while reduced technetium(IV) species such as TcO₂ are less soluble and can be retained by sediments or engineered waste forms.
Technetium has no normal commodity market as a bulk metal. Supply is tied to the nuclear industry and to isotope generation. Medical ⁹⁹ᵐTc is obtained from decay of ⁹⁹Mo in generator systems, with ⁹⁹Mo produced mainly by fission or neutron-activation routes. Long-lived ⁹⁹Tc is available as a fission product recovered in specialized facilities, but demand is limited by regulation and by its lack of ordinary commercial applications. Costs are dominated by reactor or accelerator production, radiochemical processing, transport timing, quality control, and waste management rather than by the elemental metal itself.
Made first by bombarding molybdenum with deuterons (heavy hydrogen) in a cyclotron.
Technetium has no stable nuclides, so any primordial technetium has decayed away. It is produced in stars by neutron-capture nucleosynthesis, and its spectroscopic detection in some red giant stars shows that freshly made heavy elements can be brought to stellar surfaces. In planetary materials it is expected only in trace radiogenic or cosmogenic amounts unless introduced by nuclear processes.
- Technetium was identified in molybdenum targets irradiated with deuterons.
- Its name comes from a Greek word meaning artificial.
- The diagnostic isotope ⁹⁹ᵐTc decays to ⁹⁹Tc.
- Pertechnetate, TcO₄⁻, is often the most mobile oxidized form in water.
- A visible technetium spectrum in a star proved that some stellar heavy elements are made recently.
Immagini
Proprietà
Fisiche
- Raggio atomico (empirico)
- 135 pm Confronta Raggio atomico (empirico) di tutti gli elementi →
- Raggio covalente
- 147 pm Confronta Raggio covalente di tutti gli elementi →
- Raggio di van der Waals
- 209 pm Confronta Raggio di van der Waals di tutti gli elementi →
- Raggio metallico
- 127 pm Confronta Raggio metallico di tutti gli elementi →
- Densità
- 1,1 × 104 kg/m³ Confronta Densità di tutti gli elementi →
- Volume molare
- 0,0085 L/mol
- Fase in condizioni STP
- Solido Confronta Fase in condizioni STP di tutti gli elementi →
- Punto di fusione
- 2156,85 °C Confronta Punto di fusione di tutti gli elementi →
- Punto di ebollizione
- 4264,85 °C Confronta Punto di ebollizione di tutti gli elementi →
- Conducibilità termica
- 50,6 W/(m·K) Confronta Conducibilità termica di tutti gli elementi →
- Struttura cristallina
- Esagonale compatta Confronta Struttura cristallina di tutti gli elementi →
Chimiche
- Elettronegatività (Pauling)
- 1,9 Confronta Elettronegatività (Pauling) di tutti gli elementi →
- Elettronegatività (Allen)
- 1,51
- Affinità elettronica
- 0,55 eV
- Energia di ionizzazione (1ª)
- 7,11938 eV Confronta Energia di ionizzazione (1ª) di tutti gli elementi →
- Energia di ionizzazione (2ª)
- 15,260053 eV Confronta Energia di ionizzazione (2ª) di tutti gli elementi →
- Energia di ionizzazione (3ª)
- 29,550102 eV Confronta Energia di ionizzazione (3ª) di tutti gli elementi →
- Energia di ionizzazione (4ª)
- 41,000141 eV Confronta Energia di ionizzazione (4ª) di tutti gli elementi →
- Energia di ionizzazione (5ª)
- 57,000196 eV Confronta Energia di ionizzazione (5ª) di tutti gli elementi →
- Stati di ossidazione
- −3, −1, +1, +2, +3, +4, +5, +6, +7 Confronta Stati di ossidazione di tutti gli elementi →
- Elettroni di valenza
- 7 Confronta Elettroni di valenza di tutti gli elementi →
- Configurazione elettronica
- [Kr] 5s2 4d5
Termodinamiche
- Calore di fusione
- 0,24667047 eV Confronta Calore di fusione di tutti gli elementi →
- Calore di vaporizzazione
- 5,182153 eV Confronta Calore di vaporizzazione di tutti gli elementi →
- Calore di sublimazione
- 6,063119 eV
- Calore di atomizzazione
- 6,063119 eV
- Entalpia di atomizzazione
- 7,026999 eV
Nucleari
- Protoni
- 43 Confronta Protoni di tutti gli elementi →
- Neutroni
- 55 Confronta Neutroni di tutti gli elementi →
- Isotopi noti
- 40 Confronta Isotopi noti di tutti gli elementi →
- Isotopi stabili
- 0 Confronta Isotopi stabili di tutti gli elementi →
- Numero di massa (isotopo più stabile)
- 98
- Isotopo più stabile
- Tc-98
- Anno della scoperta
- 1937
Abbondanza
N/D
Struttura cristallina
- Costante reticolare a
- 274 pm
Struttura elettronica
- Elettroni per guscio
- 2, 8, 18, 13, 2 Confronta Elettroni per guscio di tutti gli elementi →
Identificativi
- Numero CAS
- 7440-26-8 Confronta Numero CAS di tutti gli elementi →
- Simbolo di termine
- 6S5/2
- InChI
- InChI=1S/Tc
- Chiave InChI
- GKLVYJBZJHMRIY-UHFFFAOYSA-N
Configurazione elettronica Misurato
Tc: 4d⁵ 5s²[Kr] 4d⁵ 5s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁵ 5s²Modello 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
Nessun isotopo stabile.
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita |
|---|---|---|---|
| 109 Radioattivo | 108,920256 ± 0,00001 | N/D | 905 ms |
| 110 Radioattivo | 109,923744 ± 0,00001 | N/D | 900 ms |
| 111 Radioattivo | 110,925901 ± 0,000011 | N/D | 350 ms |
| 112 Radioattivo | 111,9299458 ± 0,000006 | N/D | 323 ms |
| 94 Radioattivo | 93,9096536 ± 0,0000044 | N/D | 293 minuti |
Fase / Stato
Motivo: 2131,8 °C sotto il punto di fusione (2156,85 °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 43. Ordinamento per carica ionica crescente.
Righe disponibili ?
| Ione | Carica | Righe totali | Probabilità di transizione | Designazioni dei livelli |
|---|---|---|---|---|
| Tc I | 0 | 600 | 13 | 561 |
| Tc II | +1 | 40 | 6 | 23 |
Livelli disponibili ?
| Ione | Carica | Livelli |
|---|---|---|
| Tc I | 0 | 290 |
| Tc II | +1 | 34 |
| Tc III | +2 | 2 |
| Tc IV | +3 | 2 |
| Tc V | +4 | 2 |
| Tc VI | +5 | 2 |
| Tc VII | +6 | 2 |
| Tc VIII | +7 | 2 |
| Tc IX | +8 | 2 |
| Tc X | +9 | 2 |
Raggi ionici
| Carica | Coordinazione | Spin | Raggio |
|---|---|---|---|
| +4 | 6 | N/D | 64.5 pm |
| +5 | 6 | N/D | 60 pm |
| +7 | 4 | N/D | 37 pm |
| +7 | 6 | N/D | 56.00000000000001 pm |
Composti
Isotopi (5)
Twenty-two isotopes of technetium with masses ranging from 90 to 111 are reported. All the isotopes of technetium are radioactive. It is one of two elements with Z < 83 that have no stable isotopes; the other element is promethium (Z = 61). Technetium has three long lived radioactive isotopes: 97Tc (T1/2 = 2.6 x 106 years), 98Tc (T1/2 = 4.2 x 106 years) and 99Tc (T1/2 = 2.1 x 105 years). 95Tcm ("m" stands for meta state) (T1/2 = 61 days) is used in tracer work. However, the most useful isotope of technetium is 99Tcm (T1/2 = 6.01 hours) is used in many medical radioactive isotope tests because of its half-life being short, the energy of the gamma ray it emits, and the ability of technetium to be chemically bound to many biologically active molecules. Because 99Tc is produced as a fission product from the fission of uranium in nuclear reactors, large quantities have been produced over the years. There are kilogram quantities of technetium currently existing.
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita | Modalità di decadimento | |
|---|---|---|---|---|---|
| 109 Radioattivo | 108,920256 ± 0,00001 | N/D | 905 ms | β- =100%β-n =0.08±0.2% | |
| 110 Radioattivo | 109,923744 ± 0,00001 | N/D | 900 ms | β- =100%β-n =0.04±0.2% | |
| 111 Radioattivo | 110,925901 ± 0,000011 | N/D | 350 ms | β- =100%β-n =0.85±2% | |
| 112 Radioattivo | 111,9299458 ± 0,000006 | N/D | 323 ms | β- =100%β-n =1.5±0.2% | |
| 94 Radioattivo | 93,9096536 ± 0,0000044 | N/D | 293 minuti | β+ =100% |
Righe spettrali
Sono visualizzati 50 di 277. Per impostazione predefinita sono mostrate soltanto le righe spettrali con intensità misurata.
| Lunghezza d'onda (nm) | Intensità | Stadio di ionizzazione | Tipo | Transizione | Accuratezza | Fonte | |
|---|---|---|---|---|---|---|---|
| 485.359 nm | 20000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4F* | Misurata | NIST | |
| 409.5662 nm | 15000 | Tc I | emission | 4d6.(5D).5s 6D → 4d6.(5D).5p 6D* | Misurata | NIST | |
| 408.8702 nm | 10000 | Tc I | emission | 4d6.(5D).5s 6D → 4d6.(5D).5p 6D* | Misurata | NIST | |
| 411.5065 nm | 10000 | Tc I | emission | 4d6.(5D).5s 6D → 4d6.(5D).5p 6D* | Misurata | NIST | |
| 416.5605 nm | 10000 | Tc I | emission | 4d6.(5D).5s 4D → 4d5.(6S).5s.(5S).5p 4P* | Misurata | NIST | |
| 426.2245 nm | 10000 | Tc I | emission | 4d5.5s2 6S → 4d5.(6S).5s.(7S).5p 6P* | Misurata | NIST | |
| 429.7034 nm | 10000 | Tc I | emission | 4d5.5s2 6S → 4d5.(6S).5s.(7S).5p 6P* | Misurata | NIST | |
| 452.283 nm | 10000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4D* | Misurata | NIST | |
| 474.0602 nm | 10000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4F* | Misurata | NIST | |
| 482.0744 nm | 10000 | Tc I | emission | 4d5.(6S).5s.(7S).5p 8P* → 4d5.(6S).5s.(7S).6s e 8S | Misurata | NIST | |
| 486.6732 nm | 10000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4F* | Misurata | NIST | |
| 412.4217 nm | 8000 | Tc I | emission | 4d6.(5D).5s 6D → 4d6.(5D).5p 6D* | Misurata | NIST | |
| 489.1909 nm | 8000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4F* | Misurata | NIST | |
| 414.4961 nm | 6000 | Tc I | emission | 4d6.(5D).5s 6D → 4d6.(5D).5p 6D* | Misurata | NIST | |
| 417.2523 nm | 5000 | Tc I | emission | 4d6.(5D).5s 6D → 4d6.(5D).5p 6D* | Misurata | NIST | |
| 497.6341 nm | 5000 | Tc I | emission | 4d5.(6S).5s.(7S).5p 8P* → 4d5.(6S).5s.(7S).6s e 8S | Misurata | NIST | |
| 509.6269 nm | 5000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 6F* | Misurata | NIST | |
| 417.0266 nm | 4000 | Tc I | emission | 4d6.(5D).5s 6D → 4d6.(5D).5p 6D* | Misurata | NIST | |
| 477.1539 nm | 4000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4F* | Misurata | NIST | |
| 414.5126 nm | 3000 | Tc I | emission | 4d6.(5D).5s 6D → 4d6.(5D).5p 6D* | Misurata | NIST | |
| 448.7049 nm | 3000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4D* | Misurata | NIST | |
| 463.7499 nm | 3000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4D* | Misurata | NIST | |
| 394.709 nm | 2000 | Tc I | emission | 4d6.(3H).5s 4H → 4d6.(3H).5p 2I* | Misurata | NIST | |
| 399.4498 nm | 2000 | Tc I | emission | 4d6.(3H).5s 4H → 4d6.(3H).5p 4G* | Misurata | NIST | |
| 402.0759 nm | 2000 | Tc I | emission | 4d6.(3H).5s 2H → 4d6.(3H).5p 2H* | Misurata | NIST | |
| 453.9513 nm | 2000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4D* | Misurata | NIST | |
| 456.4541 nm | 2000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4D* | Misurata | NIST | |
| 464.8328 nm | 2000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4D* | Misurata | NIST | |
| 466.9303 nm | 2000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4P* | Misurata | NIST | |
| 471.7758 nm | 2000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4F* | Misurata | NIST | |
| 490.9509 nm | 2000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4F* | Misurata | NIST | |
| 517.4813 nm | 2000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 6F* | Misurata | NIST | |
| 383.7565 nm | 1500 | Tc I | emission | 4d6.(3H).5s 4H → 4d6.(3H).5p 4I* | Misurata | NIST | |
| 564.2116 nm | 1500 | Tc I | emission | 4d6.(3F2).5s 4F → 4d6.(5D).5p 4D* | Misurata | NIST | |
| 386.8248 nm | 1000 | Tc I | emission | 4d6.(3H).5s 4H → 4d6.(3H).5p 4I* | Misurata | NIST | |
| 401.1998 nm | 1000 | Tc I | emission | 4d6.(3H).5s 4H → 4d5.(4D).5s.(5D).5p 6F* | Misurata | NIST | |
| 403.9232 nm | 1000 | Tc I | emission | 4d6.(3H).5s 4H → 4d6.(3H).5p 4G* | Misurata | NIST | |
| 411.0214 nm | 1000 | Tc I | emission | 4d6.(1I).5s 2I → 4d6.(1I).5p 2K* | Misurata | NIST | |
| 412.8263 nm | 1000 | Tc I | emission | 4d5.5s2 4G → 4d5.(4G).5s.(5G).5p 4H* | Misurata | NIST | |
| 416.966 nm | 1000 | Tc I | emission | 4d6.(3H).5s 4H → 4d5.(4G).5s.(5G).5p 4H* | Misurata | NIST | |
| 417.6253 nm | 1000 | Tc I | emission | 4d6.(5D).5s 6D → 4d6.(5D).5p 6D* | Misurata | NIST | |
| 426.2682 nm | 1000 | Tc I | emission | 4d6.(5D).5s 4D → 4d5.(6S).5s.(5S).5p 4P* | Misurata | NIST | |
| 442.9581 nm | 1000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4D* | Misurata | NIST | |
| 448.1534 nm | 1000 | Tc I | emission | 4d6.(3H).5s 2H → 4d6.(3H).5p 4H* | Misurata | NIST | |
| 451.5974 nm | 1000 | Tc I | emission | 4d6.(3H).5s 2H → 4d6.(3H).5p 4H* | Misurata | NIST | |
| 455.7038 nm | 1000 | Tc I | emission | 4d6.(3F2).5s 4F → 4d6.(3F2).5p 4G* | Misurata | NIST | |
| 457.8438 nm | 1000 | Tc I | emission | 4d6.(3G).5s 4G → 4d6.(3H).5p 2I* | Misurata | NIST | |
| 459.3334 nm | 1000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4D* | Misurata | NIST | |
| 461.6842 nm | 1000 | Tc I | emission | 4d5.(6S).5s.(7S).5p 6P* → 4d5.(6S).5s.(7S).5d f 6D | Misurata | NIST | |
| 463.0527 nm | 1000 | Tc I | emission | 4d6.(5D).5s 4D → 4d6.(5D).5p 4D* | Misurata | NIST |
Proprietà estese
Raggi covalenti (dati estesi)
- Raggio covalente (Pyykkö)
- 128 pm
- Raggio covalente (Pyykkö, legame doppio)
- 120 pm
- Raggio covalente (Pyykkö, legame triplo)
- 110 pm
Raggi di van der Waals
- Batsanov
- 205 pm
- Alvarez
- 244 pm
- UFF
- 299,8 pm
- MM3
- 236 pm
Raggi atomici e metallici
- Raggio atomico (Rahm)
- 252 pm
- Raggio metallico (C12)
- 136 pm
Scale di numerazione
- Mendeleev
- 56
- Pettifor
- 58
- Glawe
- 59
Scale di elettronegatività
- Ghosh
- 0
- Miedema
- 5
- Gunnarsson–Lundqvist
- 5
- Robles–Bartolotti
- 4
Polarizzabilità e dispersione
- Polarizzabilità dipolare
- 79 a.u.
- Polarizzabilità dipolare (inc.)
- 10 a.u.
- C₆ (Gould–Bučko)
- 939 Ha·Bohr6
Parametri di Miedema
- Volume molare di Miedema
- 8,64 cm3/mol
- Densità elettronica di Miedema
- 6
Transizioni di fase e allotropi
| Punto di fusione | 2430,15 K |
| Punto di ebollizione | 4535,15 K |
Categorie degli stati di ossidazione
Dati di riferimento avanzati
Costanti di schermaggio (10)
| n | Orbitale | σ |
|---|---|---|
| 1 | s | 0,891 |
| 2 | p | 4,0592 |
| 2 | s | 11,3718 |
| 3 | d | 14,647 |
| 3 | p | 16,6159 |
| 3 | s | 16,2088 |
| 4 | d | 30,118 |
| 4 | p | 27,1888 |
| 4 | s | 25,8016 |
| 5 | s | 35,7735 |
Dettaglio dei raggi cristallini (4)
| Carica | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 4 | VI | 78,5 | from r^3 vs V plots, from metallic oxides, | |
| 5 | VI | 74 | estimated, from r^3 vs V plots, | |
| 7 | IV | 51 | ||
| 7 | VI | 70 | Ahrens (1952) ionic radius, |
Modalità di decadimento degli isotopi (70)
| Isotopo | Modalità | Intensità |
|---|---|---|
| 83 | p | — |
| 83 | B+ | — |
| 83 | B+p | — |
| 84 | p | — |
| 84 | B+ | — |
| 84 | B+p | — |
| 85 | p | — |
| 86 | B+ | 100% |
| 86 | B+p | — |
| 87 | B+ | 100% |
Fattori di diffusione dei raggi X (508)
| Energia (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 1,1689 |
| 10,1617 | — | 1,2263 |
| 10,3261 | — | 1,28651 |
| 10,4931 | — | 1,34968 |
| 10,6628 | — | 1,41595 |
| 10,8353 | — | 1,48547 |
| 11,0106 | — | 1,55841 |
| 11,1886 | — | 1,63493 |
| 11,3696 | — | 1,7152 |
| 11,5535 | — | 1,7906 |
Dati aggiuntivi
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
Not Applicable
Riferimenti (1)
- [5] Technetium https://education.jlab.org/itselemental/ele043.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
Not Applicable
Riferimenti (1)
- [5] Technetium https://education.jlab.org/itselemental/ele043.html
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 Technetium.
The element property data was retrieved from publications.