Cesium (Cs)
alkali-metalSolid
標準原子量
132.905452 u電子配置
[Xe] 6s1融点
28.44 °C沸点
670.85 °C密度
1930 kg/m³酸化数
−1, +1電気陰性度（Pauling）
0.79第1イオン化エネルギー
3.893906 eV発見年
1860原子半径
260 pm詳細
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.
画像
性質
物理的性質
- 原子半径（経験値）
- 260 pm 全元素の原子半径（経験値）を比較 →
- 共有結合半径
- 244 pm 全元素の共有結合半径を比較 →
- ファンデルワールス半径
- 343 pm 全元素のファンデルワールス半径を比較 →
- 金属半径
- 235 pm 全元素の金属半径を比較 →
- 密度
- 1930 kg/m³ 全元素の密度を比較 →
- モル体積
- 0.07 L/mol
- 標準温度・圧力（STP）での相
- 固体 全元素の標準温度・圧力（STP）での相を比較 →
- 融点
- 28.44 °C 全元素の融点を比較 →
- 沸点
- 670.85 °C 全元素の沸点を比較 →
- 熱伝導率
- 35.9 W/(m·K) 全元素の熱伝導率を比較 →
- 比熱容量
- 0.242 J/(g·K) 全元素の比熱容量を比較 →
- モル熱容量
- 32.21 J/(mol·K) 全元素のモル熱容量を比較 →
- 結晶構造
- 体心立方構造 全元素の結晶構造を比較 →
化学的性質
- 電気陰性度（Pauling）
- 0.79 全元素の電気陰性度（Pauling）を比較 →
- 電気陰性度（Allen）
- 0.659
- 電子親和力
- 0.4716 eV
- 第1イオン化エネルギー
- 3.893906 eV 全元素の第1イオン化エネルギーを比較 →
- 第2イオン化エネルギー
- 23.15753 eV 全元素の第2イオン化エネルギーを比較 →
- 第3イオン化エネルギー
- 33.195114 eV 全元素の第3イオン化エネルギーを比較 →
- 第4イオン化エネルギー
- 43.000148 eV 全元素の第4イオン化エネルギーを比較 →
- 第5イオン化エネルギー
- 56.000193 eV 全元素の第5イオン化エネルギーを比較 →
- 酸化数
- −1, +1 全元素の酸化数を比較 →
- 価電子
- 1 全元素の価電子を比較 →
- 電子配置
- [Xe] 6s1
熱力学的性質
- 臨界点（温度）
- 1665 °C
- 臨界点（圧力）
- 9.4e+6 Pa
- 融解熱
- 0.0216614 eV 全元素の融解熱を比較 →
- 蒸発熱
- 0.67367985 eV 全元素の蒸発熱を比較 →
- 昇華熱
- 0.79286936 eV
- 原子化熱
- 0.79286936 eV
- 原子化エンタルピー
- 0.79286936 eV
原子核
- 陽子数
- 55 全元素の陽子数を比較 →
- 中性子数
- 78 全元素の中性子数を比較 →
- 既知の同位体
- 42 全元素の既知の同位体を比較 →
- 安定同位体
- 1 全元素の安定同位体を比較 →
- 最も安定な同位体
- Cs-133
- 発見年
- 1860
存在度
- 存在度（地殻）
- 3 mg/kg 全元素の存在度（地殻）を比較 →
- 存在度（海洋）
- 3 × 10−4 mg/L 全元素の存在度（海洋）を比較 →
結晶構造
- 格子定数a
- 605 pm
電子構造
- 各電子殻の電子数
- 2, 8, 18, 18, 8, 1 全元素の各電子殻の電子数を比較 →
識別子
- CAS登録番号
- 7440-46-2 全元素のCAS登録番号を比較 →
- 項記号
- 2S1/2
- InChI
- InChI=1S/Cs
- InChI Key
- TVFDJXOCXUVLDH-UHFFFAOYSA-N
電子配置 測定値
Cs: 6s¹[Xe] 6s¹1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 6s¹原子モデル
同位体によって中性子数、質量、安定性は変わりますが、中性原子の電子配置は変わりません。
模式的な原子モデルです。実際の縮尺とは異なります。
原子の指紋
発光／吸収スペクトル
同位体分布
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 |
|---|---|---|---|
| 133 安定 | 132.905451961 ± 0.000000008 | 100.0000% | 安定 |
相／状態
理由: 融点（28.44 °C）より3.4 °C低い
模式図、実際の縮尺とは異なります
相転移点
相転移エネルギー
融点で1 molを融解させるのに必要なエネルギー
沸点で1 molを蒸発させるのに必要なエネルギー
昇華点で1 molを昇華させるのに必要なエネルギー
密度
標準条件下
標準条件下
詳細
原子スペクトル
全55件中10件を表示しています。 イオンの電荷の昇順で並べています。
スペクトル線データの収録状況 ?
| イオン | 電荷 | スペクトル線の総数 | 遷移確率 | 準位の表記 |
|---|---|---|---|---|
| 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 |
準位データの収録状況 ?
| イオン | 電荷 | 準位 |
|---|---|---|
| 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 |
イオン半径
| 電荷 | 配位 | スピン | 半径 |
|---|---|---|---|
| +1 | 6 | データなし | 167 pm |
| +1 | 8 | データなし | 174 pm |
| +1 | 9 | データなし | 178 pm |
| +1 | 10 | データなし | 181 pm |
| +1 | 11 | データなし | 185 pm |
| +1 | 12 | データなし | 188 pm |
化合物
同位体 (1)
Cesium has more isotopes than any element32with masses ranging from 114 to 145.
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 | 崩壊形式 | |
|---|---|---|---|---|---|
| 133 安定 | 132.905451961 ± 0.000000008 | 100.0000% | 安定 | stable |
スペクトル線
全728件中50件を表示しています。 初期設定では、強度の測定値があるスペクトル線のみを表示します。
| 波長（nm） | 強度 | 電離段階 | 種類 | 遷移 | 精度 | 出典 | |
|---|---|---|---|---|---|---|---|
| 460.37908 nm | 10000000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | 測定値 | NIST | |
| 522.70372 nm | 7500000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | 測定値 | NIST | |
| 592.56312 nm | 5100000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[7/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | 測定値 | NIST | |
| 556.3024 nm | 3900000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[3/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | 測定値 | NIST | |
| 495.28523 nm | 3700000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | 測定値 | NIST | |
| 695.54998 nm | 3700000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[7/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | 測定値 | NIST | |
| 524.93849 nm | 2900000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | 測定値 | NIST | |
| 504.38026 nm | 2700000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | 測定値 | NIST | |
| 483.01864 nm | 2500000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | 測定値 | NIST | |
| 583.11404 nm | 2400000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | 測定値 | NIST | |
| 537.09876 nm | 2200000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | 測定値 | NIST | |
| 452.67416 nm | 2000000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | 測定値 | NIST | |
| 487.00392 nm | 1900000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | 測定値 | NIST | |
| 427.71303 nm | 1800000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | 測定値 | NIST | |
| 697.96684 nm | 1600000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[5/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | 測定値 | NIST | |
| 426.470255 nm | 1400000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[5/2] → 5p5.(2P*<3/2>).6d 2[7/2]* | 測定値 | NIST | |
| 721.9603 nm | 1400000 | Cs III | emission | 5s2.5p5 2P* → 5s2.5p5 2P* | 測定値 | NIST | |
| 714.95415 nm | 1300000 | Cs II | emission | 5p5.(2P*<1/2>).5d 2[5/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | 測定値 | NIST | |
| 450.15517 nm | 1200000 | Cs II | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | 測定値 | NIST | |
| 527.40539 nm | 1100000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | 測定値 | NIST | |
| 534.91319 nm | 1000000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | 測定値 | NIST | |
| 653.6445 nm | 1000000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | 測定値 | NIST | |
| 612.86072 nm | 980000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | 測定値 | NIST | |
| 672.44659 nm | 960000 | Cs II | emission | 5p5.(2P*<1/2>).5d 2[5/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | 測定値 | NIST | |
| 664.65663 nm | 880000 | Cs II | emission | 5p5.(2P*<1/2>).5d 2[3/2]* → 5p5.(2P*<1/2>).6p 2[1/2] | 測定値 | NIST | |
| 400.65447 nm | 860000 | Cs III | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).6p 2[3]* | 測定値 | NIST | |
| 649.55329 nm | 830000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[7/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | 測定値 | NIST | |
| 497.25963 nm | 820000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[5/2] → 5p5.(2P*<3/2>).7s 2[3/2]* | 測定値 | NIST | |
| 403.985602 nm | 800000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[5/2] → 5p5.(2P*<3/2>).6d 2[7/2]* | 測定値 | NIST | |
| 436.329875 nm | 760000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[3/2] → 5p5.(2P*<3/2>).6d 2[5/2]* | 測定値 | NIST | |
| 388.83763 nm | 740000 | Cs III | emission | 5s2.5p4.(3P<1>).5d 2[3] → 5s2.5p4.(3P<2>).6p 2[3]* | 測定値 | NIST | |
| 441.02226 nm | 720000 | Cs III | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).6p 2[2]* | 測定値 | NIST | |
| 450.67197 nm | 720000 | Cs III | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).6p 2[2]* | 測定値 | NIST | |
| 476.36362 nm | 700000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[1/2] | 測定値 | NIST | |
| 520.95813 nm | 650000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | 測定値 | NIST | |
| 392.55957 nm | 620000 | Cs III | emission | 5s2.5p4.(3P<2>).5d 2[3] → 5s2.5p4.(3P<2>).6p 2[3]* | 測定値 | NIST | |
| 442.56759 nm | 560000 | Cs III | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).6p 2[2]* | 測定値 | NIST | |
| 428.837507 nm | 510000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[3/2] → 5p5.(2P*<3/2>).6d 2[5/2]* | 測定値 | NIST | |
| 488.00516 nm | 490000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[1/2] | 測定値 | NIST | |
| 581.41641 nm | 450000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[3/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | 測定値 | NIST | |
| 395.95055 nm | 420000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | 測定値 | NIST | |
| 461.61693 nm | 420000 | Cs II | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).6p 2[1/2] | 測定値 | NIST | |
| 453.896566 nm | 410000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[3/2] → 5p5.(2P*<3/2>).6d 2[3/2]* | 測定値 | NIST | |
| 440.525568 nm | 390000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[1/2] → 5p5.(2P*<3/2>).7s 2[3/2]* | 測定値 | NIST | |
| 437.30356 nm | 370000 | Cs II | emission | 5p5.(2P*<3/2>).5d 2[1/2]* → 5p5.(2P*<3/2>).6p 2[3/2] | 測定値 | NIST | |
| 452.28578 nm | 350000 | Cs III | emission | 5s2.5p4.(3P<2>).6s 2[2] → 5s2.5p4.(3P<2>).6p 2[2]* | 測定値 | NIST | |
| 389.698641 nm | 340000 | Cs II | emission | 5p5.(2P*<3/2>).6p 2[1/2] → 5p5.(2P*<3/2>).6d 2[1/2]* | 測定値 | NIST | |
| 404.34262 nm | 310000 | Cs III | emission | 5s2.5p4.(1D<2>).6s 2[2] → 5s2.5p4.(1D<2>).6p 2[3]* | 測定値 | NIST | |
| 645.6318 nm | 310000 | Cs III | emission | 5s2.5p4.(3P<2>).7p 2[3]* → 5s2.5p4.(3P<2>).7d 2[4] | 測定値 | NIST | |
| 607.9854 nm | 300000 | Cs III | emission | 5s2.5p4.(3P<2>).5f 2[2]* → 5s2.5p4.(3P<2>).5g 2[3] | 測定値 | NIST |
詳細な性質
共有結合半径（詳細）
- 共有結合半径（Pyykkö）
- 232 pm
- 共有結合半径（Pyykkö、二重結合）
- 209 pm
- 共有結合半径（Bragg）
- 237 pm
ファンデルワールス半径
- Truhlar
- 343 pm
- Batsanov
- 300 pm
- Alvarez
- 348 pm
- UFF
- 451.7 pm
- MM3
- 344 pm
原子半径と金属半径
- 原子半径（Rahm）
- 249 pm
- 金属半径（C12）
- 267 pm
番号付けの尺度
- Mendeleev
- 5
- Pettifor
- 8
- Glawe
- 8
電気陰性度の尺度
- Ghosh
- 0
- Miedema
- 2
- Gunnarsson–Lundqvist
- 2
- Robles–Bartolotti
- 1
分極率と分散
- 双極子分極率
- 400.9 a.u.
- 双極子分極率（不確かさ）
- 0.7 a.u.
- C₆ (Gould–Bučko)
- 6660 Ha·Bohr6
ミーデマパラメータ
- ミーデマモル体積
- 69.23 cm3/mol
- ミーデマ電子密度
- 0
相転移と同素体
| 融点 | 301.65 K |
| 沸点 | 944.15 K |
| 臨界点（温度） | 1938.15 K |
| 臨界点（圧力） | 9.4 MPa |
酸化数の分類
専門参考データ
遮蔽定数 (12)
| n | 軌道 | 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 |
結晶半径の詳細 (6)
| 電荷 | CN | スピン | rcrystal (pm) | 由来 |
|---|---|---|---|---|
| 1 | VI | 181 | ||
| 1 | VIII | 188 | ||
| 1 | IX | 192 | ||
| 1 | X | 195 | ||
| 1 | XI | 199 | ||
| 1 | XII | 202 |
同位体の崩壊形式 (74)
| 同位体 | モード | 強度 |
|---|---|---|
| 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% |
X線散乱因子 (508)
| エネルギー (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 |
追加データ
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
3 milligrams per kilogram
参考文献 (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
3×10-4 milligrams per liter
参考文献 (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.
参考文献 (1)
- [6] Cesium https://periodic.lanl.gov/55.shtml
参考文献
(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.