Cesium (Cs)
alkali-metalSolid
Peso atomico standard
132,905452 uConfigurazione elettronica
[Xe] 6s1Punto di fusione
28,44 °CPunto di ebollizione
670,85 °CDensità
1930 kg/m³Stati di ossidazione
−1, +1Elettronegatività (Pauling)
0,79Energia di ionizzazione (1ª)
3,893906 eVAnno della scoperta
1860Raggio atomico
260 pmDettagli
Cesium is a soft alkali metal with very low ionization energy and an unusually low melting point for a metal. It occurs naturally as the single stable isotope ¹³³Cs, chiefly in rare granitic pegmatite minerals. Chemically it is the heaviest stable group 1 element and forms almost exclusively Cs⁺ salts. Its best-known technological role is in the definition of the second, based on the microwave transition of the ¹³³Cs atom.
The metal is characterized by a spectrum containing two bright lines in the blue along with several others in the red, yellow, and green wavelengths. It is silvery white, soft, and ductile. It is the most electropositive and most alkaline element.
Cesium, gallium, and mercury are the only three metals that are liquid at room temperature. Cesium reacts explosively with cold water, and reacts with ice at temperatures above -116C. Cesium hydroxide, the strongest base known, attacks glass.
The name derives from the Latin caesius for "sky blue", which was the colour of the caesium line in the spectroscope. Caesium was discovered by the German chemist Robert Wilhelm Bunsen and the German physicist Gustav Robert Kirchhoff in 1860. It was first isolated by the German chemist Carl Setterberg in 1882.
Cesium was discovered by Robert Wilhelm Bunsen and Gustav Robert Kirchhoff, German chemists, in 1860 through the spectroscopic analysis of Durkheim mineral water. They named cesium after the blue lines they observed in its spectrum. Today, cesium is primarily obtained from the mineral pollucite (CsAlSi2O6). Obtaining pure cesium is difficult since cesium ores are frequently contaminated with rubidium, an element that is chemically similar to cesium. To obtain pure cesium, cesium and rubidium ores are crushed and heated with sodium metal to 650°C, forming an alloy that can then be separated with a process known as fractional distillation. Metallic cesium is too reactive to easily handle and is usually sold in the form of cesium azide (CsN3). Cesium is recovered from cesium azide by heating it.
From the Latin word caesius, sky blue. Cesium was discovered spectroscopically in 1860 by Bunsen and Kirchhoff in mineral water from Durkheim.
Pure cesium is a pale gold, silvery metal that is solid near ordinary room temperature but melts at about 28.5 °C. It is extremely soft and must be kept under dry inert gas, vacuum, or mineral oil because fresh surfaces tarnish and react rapidly with air or moisture.
Cesium vapor is used in atomic clocks and frequency standards, where ¹³³Cs provides a reproducible microwave reference. Cesium compounds are used in specialty photoemissive and scintillation materials, in some radiation detectors, and in high-density cesium formate brines for demanding oil and gas drilling operations. Radioactive ¹³⁷Cs has been used in industrial gauges, calibration sources, and radiotherapy, although many applications now use alternatives where security or disposal is difficult.
Cesium has the second lowest melting point of all metallic elements, which limits its uses. Cesium readily combines with oxygen and is used as a getter, a material that combines with and removes trace gases from vacuum tubes. Cesium is also used in atomic clocks, in photoelectric cells and as a catalyst in the hydrogenation of certain organic compounds. Since it is easily ionized and has a high mass, cesium ions may one day be used as a propellant in ion engines on spacecraft.
Cesium reacts violently with water and ice, forming cesium hydroxide (CsOH). Cesium hydroxide is the strongest base known and will attack glass. Cesium chloride (CsCl) and cesium nitrate (CsNO3) are cesium's most common compounds and are primarily used in the production of other chemicals.
Because of it has great affinity for oxygen, the metal is used as a "getter" in electron tubes. It is also used in photoelectric cells, as well as a catalyst in the hydrogenation of certain organic compounds.
The metal has recently found application in ion propulsion systems. Cesium is used in atomic clocks, which are accurate to 5 s in 300 years. Its chief compounds are the chloride and the nitrate.
Isotopes in Biology
137Cs (with a half-life of 30 years) can be used as a tracer in fungal mycelia (an extensive matrix of underground hyphae (stems of growth from a fungus)) to monitor the immobilization of this radioactive caesium isotope. After the nuclear reactor accident at Chernobyl, large quantities of 137Cs were released as fission products into the environment. Areas with large fungal populations and fungal mycelia seemed to immobilize the 137Cs isotope, which limited the spread of the radioactive isotope [399] S. N. Gray, J. Dighton, S. Olsson, D. H. Jennings. New Phytol.129, 449 (1995)., [400] J. Dighton, G. M. Clint, J. Poskitt. Mycol. Res.95, 1052 (1991)..
Isotopes in Earth/Planetary Science
River floodplains are an important site for storing suspended sediments and contaminants transferred from upstream catchments. 137Cs measurements of floodplain sediments provide a technique for estimating overbank sediment deposition, and it can provide information on spatial patterns of sediment deposition (Fig. IUPAC.55.1) [401] R. H. Gardner, W. W. Hargrove, D. A. Levine, S. M. Pearson, K. A. Rose. Spatial Analysis of Cesium in Sediments of Watts Bar Reservoir, Oak Ridge National Laboratory (2014), Feb. 27; http://research.esd.ornl.gov/CRERP/WATTSBAR/INDEX.HTM., [402] C. R. Olsen, I. L. Larson, P. D. Lowry, C. R. Moriones, C. J. Ford, K. C. Dearstone, R. R. Turner, B. L. Kimmel, C. C. Brandt. Transport and Accumulation of Cesium-137 and Mercury in the Clinch River and Watts Bar Reservoir system, ORNL/ER-7, Oak Ridge National Laboratory, Oak Ridge, TN (1992)., [403] D. E. Walling, Q. He. Catena29, 263 (1997)..
Isotopes in Geochronology
Nuclear fission of 235U (or other fissionable materials) yields 137Cs as a product. Although 137Cs is not naturally present in the environment, it can be collected from nuclear reactor processing and then used as an environmental tracer. 137Cs adheres tightly to porous sediments and will follow the movement of the sediment. By exposing sediments to 137Cs and allowing this combination to move dynamically, gamma ray spectrometry can then be used to measure the activity of 137Cs and monitor the movement of the radioactive sediments [404] W. G. Winn. J. Radioanal. Nucl. Chem.195, 345 (1995)., [405] A. V. Chesnokov, A. P. Govorun, F. V. N., O. P. Ivanov, V. I. Liksonov, V. N. Potapov, S. B. Shcherbak, S. V. Smirnov, L. I. Urutskoev. Nucl. Instrm. Methods Phys. Res. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.420, 336 (1999)., [406] A. Albrecht, R. Reiser, A. Lück, J. M. A. Stoll, W. Giger. Environ. Sci. Technol.32, 1882 (1998)..
137Cs dating of sediments not older than 60 years is useful in natural and artificial lakes and other environments because of its widespread production and release during atmospheric nuclear weapons testing, which began in the late 1940s, plus subsequent releases, such as during the accident at the Chernobyl nuclear reactor in April 1986. The 137Cs concentration profile in a sediment core can be matched with the historical record of 137Cs release to determine the approximate age profile of the sediment [406] A. Albrecht, R. Reiser, A. Lück, J. M. A. Stoll, W. Giger. Environ. Sci. Technol.32, 1882 (1998)., [407] M. S. Humphries, A. Kindness, W. N. Ellery, J. C. Hughes, C. R. Benitez-Nelson. Geomorphology119, 88 (2010)..
Isotopes in Industry
High-energy gamma rays from 137Cs serve as food irradiation devices to remove bacteria and other harmful microorganisms (living single celled organisms such as virus, algae and fungus) from food. Although 137Cs is not used commercially for large-scale food irradiation, it has been proposed that it can be used this way. Gamma rays from the radioactive 137Cs destroy the DNA of organisms to enable foods to last longer (i.e. irradiation of fruits and vegetables stops the ripening process) and be contamination free [408] D. W. Hayer. J. Food Quality13, 147 (1990)., [409] United States General Accounting Office. Food Irradiation: Available Research Indicates that Benefits Outweigh the Risks, GAO/RCED-00-217, GAO (2000)..
Cesium chemistry is dominated by the +1 oxidation state and by large, highly soluble salts. Cesium chloride (CsCl), cesium nitrate (CsNO₃), cesium carbonate (Cs₂CO₃), and cesium sulfate (Cs₂SO₄) are common laboratory compounds. Cesium hydroxide (CsOH) is a very strong base, and cesium fluoride (CsF) is valued as a fluoride source in some syntheses. The element forms oxides and superoxides, including cesium superoxide (CsO₂), when exposed to oxygen under suitable conditions.
See more information at the Cesium compound page.
Metallic cesium is highly reactive and can ignite or explode on contact with water, forming cesium hydroxide (CsOH) and hydrogen (H₂). Soluble cesium salts can be taken up by the body in ways broadly similar to potassium, so toxic or radioactive isotopes require strict control. ¹³⁷Cs is a significant gamma-emitting contamination hazard because it is mobile in many environments and has a half-life of about 30 years.
Natural cesium is a trace constituent of crustal rocks and is enriched in some pegmatites. In soils and sediments, Cs⁺ can be strongly fixed by clay minerals, especially at selective exchange sites, but mobility increases in low-clay or organic-rich settings. Fallout-derived ¹³⁷Cs is useful as an environmental tracer, while accidental releases can contaminate food chains through uptake by plants and animals.
Cesium is produced in small quantities compared with major industrial metals. The principal ore mineral is pollucite, a hydrated cesium aluminosilicate found in rare pegmatite deposits. Processing commonly converts ore to soluble cesium salts, from which metal or specialty compounds can be prepared. Demand is concentrated in specialized uses, so supply is shaped more by a few deposits, inventory management, and technical purity than by broad commodity trading. Recycling is limited, except for controlled recovery of sealed radioactive sources and some specialty materials.
Cesium, an alkali metal, occurs in lepidolite, pollucte (a hydrated silicate of aluminum and cesium), and in other sources. One of the world's richest sources of cesium is located at Bernic Lake, Manitoba. The deposits are estimated to contain 300,000 tons of pollucite, averaging 20% cesium.
It can be isolated by elecytrolysis of the fused cyanide and by a number of other methods. Very pure, gas-free cesium can be prepared by thermal decomposition of cesium azide.
Cesium is a rare element in cosmic terms. Its stable isotope ¹³³Cs is produced mainly by slow neutron-capture processes in evolved stars, with contributions from other neutron-rich nucleosynthesis pathways. In planetary materials it behaves as an incompatible, lithophile alkali element, tending to concentrate in late-stage melts rather than in common rock-forming minerals.
- Cesium is one of the few metals that can melt in a warm hand, though handling it that way would be dangerous.
- The official SI second is defined using a hyperfine transition of neutral ¹³³Cs.
- Pollucite is important because cesium has few concentrated ore minerals.
- Cesium salts often make dense solutions because the Cs⁺ ion is very heavy.
- The name comes from the blue spectral lines observed when the element was discovered.
Immagini
Proprietà
Fisiche
- Raggio atomico (empirico)
- 260 pm Confronta Raggio atomico (empirico) di tutti gli elementi →
- Raggio covalente
- 244 pm Confronta Raggio covalente di tutti gli elementi →
- Raggio di van der Waals
- 343 pm Confronta Raggio di van der Waals di tutti gli elementi →
- Raggio metallico
- 235 pm Confronta Raggio metallico di tutti gli elementi →
- Densità
- 1930 kg/m³ Confronta Densità di tutti gli elementi →
- Volume molare
- 0,07 L/mol
- Fase in condizioni STP
- Solido Confronta Fase in condizioni STP di tutti gli elementi →
- Punto di fusione
- 28,44 °C Confronta Punto di fusione di tutti gli elementi →
- Punto di ebollizione
- 670,85 °C Confronta Punto di ebollizione di tutti gli elementi →
- Conducibilità termica
- 35,9 W/(m·K) Confronta Conducibilità termica di tutti gli elementi →
- Capacità termica specifica
- 0,242 J/(g·K) Confronta Capacità termica specifica di tutti gli elementi →
- Capacità termica molare
- 32,21 J/(mol·K) Confronta Capacità termica molare di tutti gli elementi →
- Struttura cristallina
- Cubica a corpo centrato Confronta Struttura cristallina di tutti gli elementi →
Chimiche
- Elettronegatività (Pauling)
- 0,79 Confronta Elettronegatività (Pauling) di tutti gli elementi →
- Elettronegatività (Allen)
- 0,659
- Affinità elettronica
- 0,4716 eV
- Energia di ionizzazione (1ª)
- 3,893906 eV Confronta Energia di ionizzazione (1ª) di tutti gli elementi →
- Energia di ionizzazione (2ª)
- 23,15753 eV Confronta Energia di ionizzazione (2ª) di tutti gli elementi →
- Energia di ionizzazione (3ª)
- 33,195114 eV Confronta Energia di ionizzazione (3ª) di tutti gli elementi →
- Energia di ionizzazione (4ª)
- 43,000148 eV Confronta Energia di ionizzazione (4ª) di tutti gli elementi →
- Energia di ionizzazione (5ª)
- 56,000193 eV Confronta Energia di ionizzazione (5ª) di tutti gli elementi →
- Stati di ossidazione
- −1, +1 Confronta Stati di ossidazione di tutti gli elementi →
- Elettroni di valenza
- 1 Confronta Elettroni di valenza di tutti gli elementi →
- Configurazione elettronica
- [Xe] 6s1
Termodinamiche
- Punto critico (temperatura)
- 1665 °C
- Punto critico (pressione)
- 9,4e+6 Pa
- Calore di fusione
- 0,0216614 eV Confronta Calore di fusione di tutti gli elementi →
- Calore di vaporizzazione
- 0,67367985 eV Confronta Calore di vaporizzazione di tutti gli elementi →
- Calore di sublimazione
- 0,79286936 eV
- Calore di atomizzazione
- 0,79286936 eV
- Entalpia di atomizzazione
- 0,79286936 eV
Nucleari
- Protoni
- 55 Confronta Protoni di tutti gli elementi →
- Neutroni
- 78 Confronta Neutroni di tutti gli elementi →
- Isotopi noti
- 42 Confronta Isotopi noti di tutti gli elementi →
- Isotopi stabili
- 1 Confronta Isotopi stabili di tutti gli elementi →
- Isotopo più stabile
- Cs-133
- Anno della scoperta
- 1860
Abbondanza
- Abbondanza (crosta terrestre)
- 3 mg/kg Confronta Abbondanza (crosta terrestre) di tutti gli elementi →
- Abbondanza (oceano)
- 3 × 10−4 mg/L Confronta Abbondanza (oceano) di tutti gli elementi →
Struttura cristallina
- Costante reticolare a
- 605 pm
Struttura elettronica
- Elettroni per guscio
- 2, 8, 18, 18, 8, 1 Confronta Elettroni per guscio di tutti gli elementi →
Identificativi
- Numero CAS
- 7440-46-2 Confronta Numero CAS di tutti gli elementi →
- Simbolo di termine
- 2S1/2
- InChI
- InChI=1S/Cs
- Chiave InChI
- TVFDJXOCXUVLDH-UHFFFAOYSA-N
Configurazione elettronica Misurato
Cs: 6s¹[Xe] 6s¹1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 6s¹Modello 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 |
|---|---|---|---|
| 133 Stabile | 132,905451961 ± 0,000000008 | 100,0000% | Stabile |
Fase / Stato
Motivo: 3,4 °C sotto il punto di fusione (28,44 °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
Avanzate
Spettri atomici
Sono visualizzati 10 di 55. Ordinamento per carica ionica crescente.
Righe disponibili ?
| Ione | Carica | Righe totali | Probabilità di transizione | Designazioni dei livelli |
|---|---|---|---|---|
| Cs I | 0 | 230 | 42 | 228 |
| Cs II | +1 | 1757 | 2 | 1737 |
| Cs III | +2 | 1010 | 1010 | 1010 |
| Cs IV | +3 | 207 | 0 | 207 |
| Cs V | +4 | 143 | 0 | 143 |
| Cs VI | +5 | 67 | 0 | 67 |
| Cs VII | +6 | 185 | 0 | 185 |
| Cs VIII | +7 | 111 | 13 | 111 |
| Cs IX | +8 | 50 | 16 | 50 |
| Cs X | +9 | 86 | 86 | 86 |
Livelli disponibili ?
| Ione | Carica | Livelli |
|---|---|---|
| Cs I | 0 | 179 |
| Cs II | +1 | 316 |
| Cs III | +2 | 174 |
| Cs IV | +3 | 116 |
| Cs V | +4 | 50 |
| Cs VI | +5 | 32 |
| Cs VII | +6 | 79 |
| Cs VIII | +7 | 55 |
| Cs IX | +8 | 69 |
| Cs X | +9 | 79 |
Raggi ionici
| Carica | Coordinazione | Spin | Raggio |
|---|---|---|---|
| +1 | 6 | N/D | 167 pm |
| +1 | 8 | N/D | 174 pm |
| +1 | 9 | N/D | 178 pm |
| +1 | 10 | N/D | 181 pm |
| +1 | 11 | N/D | 185 pm |
| +1 | 12 | N/D | 188 pm |
Composti
Isotopi (1)
Cesium has more isotopes than any element32with masses ranging from 114 to 145.
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita | Modalità di decadimento | |
|---|---|---|---|---|---|
| 133 Stabile | 132,905451961 ± 0,000000008 | 100,0000% | Stabile | stable |
Righe spettrali
Sono visualizzati 50 di 728. Per impostazione predefinita sono mostrate soltanto le righe spettrali con intensità misurata.
| Lunghezza d'onda (nm) | Intensità | Stadio di ionizzazione | Tipo | Transizione | Accuratezza | Fonte | |
|---|---|---|---|---|---|---|---|
| 460.37908 nm | 10000000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Misurata | NIST | |
| 522.70372 nm | 7500000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | Misurata | NIST | |
| 592.56312 nm | 5100000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[7/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Misurata | NIST | |
| 556.3024 nm | 3900000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[3/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | Misurata | NIST | |
| 495.28523 nm | 3700000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Misurata | NIST | |
| 695.54998 nm | 3700000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[7/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Misurata | NIST | |
| 524.93849 nm | 2900000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | Misurata | NIST | |
| 504.38026 nm | 2700000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | Misurata | NIST | |
| 483.01864 nm | 2500000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Misurata | NIST | |
| 583.11404 nm | 2400000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Misurata | NIST | |
| 537.09876 nm | 2200000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | Misurata | NIST | |
| 452.67416 nm | 2000000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | Misurata | NIST | |
| 487.00392 nm | 1900000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | Misurata | NIST | |
| 427.71303 nm | 1800000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | Misurata | NIST | |
| 697.96684 nm | 1600000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[5/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | Misurata | NIST | |
| 426.470255 nm | 1400000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[5/2] → 5p5.(2P*<3/2>).6d 2[7/2]* | Misurata | NIST | |
| 721.9603 nm | 1400000 | Cs III | emission | 5s2.5p5 2P* → 5s2.5p5 2P* | Misurata | NIST | |
| 714.95415 nm | 1300000 | Cs II | emission | 5p5.(2P*<1/2>).5d 2[5/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | Misurata | NIST | |
| 450.15517 nm | 1200000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | Misurata | NIST | |
| 527.40539 nm | 1100000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | Misurata | NIST | |
| 534.91319 nm | 1000000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | Misurata | NIST | |
| 653.6445 nm | 1000000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Misurata | NIST | |
| 612.86072 nm | 980000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Misurata | NIST | |
| 672.44659 nm | 960000 | Cs II | emission | 5p5.(2P*<1/2>).5d 2[5/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | Misurata | NIST | |
| 664.65663 nm | 880000 | Cs II | emission | 5p5.(2P*<1/2>).5d 2[3/2]* → 5p5.(2P*<1/2>).6p 2[1/2] | Misurata | NIST | |
| 400.65447 nm | 860000 | Cs III | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).6p 2[3]* | Misurata | NIST | |
| 649.55329 nm | 830000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[7/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Misurata | NIST | |
| 497.25963 nm | 820000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[5/2] → 5p5.(2P*<3/2>).7s 2[3/2]* | Misurata | NIST | |
| 403.985602 nm | 800000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[5/2] → 5p5.(2P*<3/2>).6d 2[7/2]* | Misurata | NIST | |
| 436.329875 nm | 760000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[3/2] → 5p5.(2P*<3/2>).6d 2[5/2]* | Misurata | NIST | |
| 388.83763 nm | 740000 | Cs III | emission | 5s2.5p4.(3P<1>).5d 2[3] → 5s2.5p4.(3P<2>).6p 2[3]* | Misurata | NIST | |
| 441.02226 nm | 720000 | Cs III | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).6p 2[2]* | Misurata | NIST | |
| 450.67197 nm | 720000 | Cs III | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).6p 2[2]* | Misurata | NIST | |
| 476.36362 nm | 700000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[1/2] | Misurata | NIST | |
| 520.95813 nm | 650000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | Misurata | NIST | |
| 392.55957 nm | 620000 | Cs III | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).6p 2[3]* | Misurata | NIST | |
| 442.56759 nm | 560000 | Cs III | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).6p 2[2]* | Misurata | NIST | |
| 428.837507 nm | 510000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[3/2] → 5p5.(2P*<3/2>).6d 2[5/2]* | Misurata | NIST | |
| 488.00516 nm | 490000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[1/2] | Misurata | NIST | |
| 581.41641 nm | 450000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[3/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | Misurata | NIST | |
| 395.95055 nm | 420000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | Misurata | NIST | |
| 461.61693 nm | 420000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[1/2] | Misurata | NIST | |
| 453.896566 nm | 410000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[3/2] → 5p5.(2P*<3/2>).6d 2[3/2]* | Misurata | NIST | |
| 440.525568 nm | 390000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[1/2] → 5p5.(2P*<3/2>).7s 2[3/2]* | Misurata | NIST | |
| 437.30356 nm | 370000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | Misurata | NIST | |
| 452.28578 nm | 350000 | Cs III | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).6p 2[2]* | Misurata | NIST | |
| 389.698641 nm | 340000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[1/2] → 5p5.(2P*<3/2>).6d 2[1/2]* | Misurata | NIST | |
| 404.34262 nm | 310000 | Cs III | emission | 5s2.5p4.(1D<2>).6s 2[2] → 5s2.5p4.(1D<2>).6p 2[3]* | Misurata | NIST | |
| 645.6318 nm | 310000 | Cs III | emission | 5s2.5p4.(3P<2>).7p 2[3]* → 5s2.5p4.(3P<2>).7d 2[4] | Misurata | NIST | |
| 607.9854 nm | 300000 | Cs III | emission | 5s2.5p4.(3P<2>).5f 2[2]* → 5s2.5p4.(3P<2>).5g 2[3] | Misurata | NIST |
Proprietà estese
Raggi covalenti (dati estesi)
- Raggio covalente (Pyykkö)
- 232 pm
- Raggio covalente (Pyykkö, legame doppio)
- 209 pm
- Raggio covalente (Bragg)
- 237 pm
Raggi di van der Waals
- Truhlar
- 343 pm
- Batsanov
- 300 pm
- Alvarez
- 348 pm
- UFF
- 451,7 pm
- MM3
- 344 pm
Raggi atomici e metallici
- Raggio atomico (Rahm)
- 249 pm
- Raggio metallico (C12)
- 267 pm
Scale di numerazione
- Mendeleev
- 5
- Pettifor
- 8
- Glawe
- 8
Scale di elettronegatività
- Ghosh
- 0
- Miedema
- 2
- Gunnarsson–Lundqvist
- 2
- Robles–Bartolotti
- 1
Polarizzabilità e dispersione
- Polarizzabilità dipolare
- 400,9 a.u.
- Polarizzabilità dipolare (inc.)
- 0,7 a.u.
- C₆ (Gould–Bučko)
- 6660 Ha·Bohr6
Parametri di Miedema
- Volume molare di Miedema
- 69,23 cm3/mol
- Densità elettronica di Miedema
- 0
Transizioni di fase e allotropi
| Punto di fusione | 301,65 K |
| Punto di ebollizione | 944,15 K |
| Punto critico (temperatura) | 1938,15 K |
| Punto critico (pressione) | 9,4 MPa |
Categorie degli stati di ossidazione
Dati di riferimento avanzati
Costanti di schermaggio (12)
| n | Orbitale | σ |
|---|---|---|
| 1 | s | 1,0957 |
| 2 | p | 4,1804 |
| 2 | s | 14,4884 |
| 3 | d | 14,0194 |
| 3 | p | 18,4222 |
| 3 | s | 18,6226 |
| 4 | d | 32,1616 |
| 4 | p | 29,1424 |
| 4 | s | 27,9576 |
| 5 | p | 41,349 |
Dettaglio dei raggi cristallini (6)
| Carica | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 1 | VI | 181 | ||
| 1 | VIII | 188 | ||
| 1 | IX | 192 | ||
| 1 | X | 195 | ||
| 1 | XI | 199 | ||
| 1 | XII | 202 |
Modalità di decadimento degli isotopi (74)
| Isotopo | Modalità | Intensità |
|---|---|---|
| 111 | p | — |
| 112 | p | 100% |
| 112 | A | 0,3% |
| 113 | p | 100% |
| 114 | B+ | 100% |
| 114 | A | 0% |
| 114 | B+p | 8,7% |
| 114 | B+A | 0,2% |
| 115 | B+ | 100% |
| 115 | B+p | 0,1% |
Fattori di diffusione dei raggi X (508)
| Energia (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0,04294 |
| 10,1617 | — | 0,04199 |
| 10,3261 | — | 0,04106 |
| 10,4931 | — | 0,04015 |
| 10,6628 | — | 0,03925 |
| 10,8353 | — | 0,03838 |
| 11,0106 | — | 0,04186 |
| 11,1886 | — | 0,04987 |
| 11,3696 | — | 0,06291 |
| 11,5535 | — | 0,06823 |
Dati aggiuntivi
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
3 milligrams per kilogram
Riferimenti (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
3×10-4 milligrams per liter
Riferimenti (1)
Sources
Sources of this element.
Cesium, an alkali metal, occurs in lepidolite, pollucte (a hydrated silicate of aluminum and cesium), and in other sources. One of the world's richest sources of cesium is located at Bernic Lake, Manitoba. The deposits are estimated to contain 300,000 tons of pollucite, averaging 20% cesium.
It can be isolated by elecytrolysis of the fused cyanide and by a number of other methods. Very pure, gas-free cesium can be prepared by thermal decomposition of cesium azide.
Riferimenti (1)
- [6] Cesium https://periodic.lanl.gov/55.shtml
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 Cesium.
The element property data was retrieved from publications.