Chromium (Cr)
transition-metalSolid
標準原子量
51.9961 u電子配置
[Ar] 3d5 4s1融点
1906.85 °C沸点
2670.85 °C密度
7150 kg/m³酸化数
−4, −2, −1, 0, +1, +2, +3, +4, +5, +6電気陰性度（Pauling）
1.66第1イオン化エネルギー
6.76651 eV発見年
1797原子半径
140 pm詳細
Chromium is a hard transition metal best known for forming adherent, protective oxide films and for giving many minerals and compounds strong colors. It occurs mainly in chromite ores and is an important alloying element in stainless and heat-resisting steels. Its chemistry spans several oxidation states, especially +3 and +6, with a sharp contrast between relatively stable Cr(III) compounds and strongly oxidizing, often toxic Cr(VI) species.
Chromium is used extensively in automobile trim as chromium metal because of its shiny finish and corrosion resistance.
The name derives from the Greek chroma for "colour", from the many coloured compounds of chromium. It was discovered in 1797 by the French chemist and pharmacist Nicolas-Louis Vauquelin, who also isolated chromium in 1798.
Chromium was discovered by Louis-Nicholas Vauquelin while experimenting with a material known as Siberian red lead, also known as the mineral crocoite (PbCrO4), in 1797. He produced chromium oxide (CrO3) by mixing crocoite with hydrochloric acid (HCl). Although he believed a method for isolating chromium didn't yet exist, Vauquelin was pleasantly surprised in 1798 to discover that he was able to obtain metallic chromium by simply heating chromium oxide in a charcoal oven. Today, chromium is primarily obtained by heating the mineral chromite (FeCr2O4) in the presence of aluminum or silicon.
From the Greek word chroma, color. Chromium is a steel-gray, lustrous, hard metal that takes a high polish. Discovered in 1797 by the Frenchman Louis Nicolas Vauquelin.
Pure chromium is a lustrous, silvery-gray metal with a high polish and a relatively high melting point. It is hard and brittle at room temperature, and its surface is rapidly passivated by a very thin oxide layer that resists further corrosion under many conditions.
The largest use of chromium is in ferrochrome for stainless steel, where chromium provides corrosion resistance by forming a passive surface film. It is also used in tool steels, superalloys, wear-resistant coatings, and hard chromium electroplating. Chromium compounds have been used in pigments, leather tanning, wood preservation, catalysts, and refractory materials, although several Cr(VI)-based uses have been restricted or replaced because of toxicity and environmental persistence.
Chromium is a blue-white metal that is hard, brittle and very corrosion resistant. Chromium can be polished to form a very shiny surface and is often plated to other metals to form a protective and attractive covering. Chromium is added to steel to harden it and to form stainless steel, a steel alloy that contains at least 10% chromium. Other chromium-steel alloys are used to make armor plate, safes, ball bearings and cutting tools.
Chromium forms many colorful compounds that have industrial uses. Lead chromate (PbCrO4), also known as chrome yellow, has been used as a yellow pigment in paints. Chromic oxide (Cr2O3), also known as chrome green, is the ninth most abundant compound in the earth's crust and is a widely used green pigment. Rubies and emeralds also owe their colors to chromium compounds. Potassium dichromate (K2Cr2O7) is used in the tanning of leather while other chromium compounds are used as mordants, materials which permanently fix dyes to fabrics. Chromium compounds are also used to anodize aluminum, a process which coats aluminum with a thick, protective layer of oxide. Chromite, chromium's primary ore, is used to make molds for the firing of bricks because of its high melting point, moderate thermal expansion and stable crystal structure.
Chromium is used to harden steel, manufacture stainless steel, and form many useful alloys. It is mostly used in plating to produce a hard, beautiful surface and to prevent corrosion. Chromium gives glass an emerald green color and is widely used as a catalyst.
The refractory industry uses chromite for forming bricks and shapes, as it has a high melting point, moderate thermal expansion, and stability of crystalline structure.
Isotopes in Earth/Planetary Science
Molecules, atoms, and ions of the stable isotopes of chromium possess slightly different physical and chemical properties, and they commonly will be fractionated during physical, chemical, and biological processes, giving rise to variations in isotopic abundances and in atomic weights. There are measureable variations in the isotopic abundances of chromium in natural terrestrial materials (Fig. IUPAC.24.1).
SiC grains are formed in very high-temperature events that occurred before the formation of the Solar System. The chemical and isotopic composition of certain elements in these grains, such as chromium, provides insights into the origin of the Solar System. The 54Cr nucleus is only produced by supernovae. Excess amounts of this isotope in the SiC grains (relative to terrestrial isotopic composition) in primitive meteorites suggest a heterogeneous distribution of 54Cr in the early Solar System and different sources of material to our Solar System [206] L. Qin, L. R. Nittler, C. M. O. D. Alexander, J. Wang, F. J. Stadermann, R. W. Carlson. Geochim. Cosmochim. Acta.75, 629 (2010).. The early solar nebula was divided into two components. One contained chromium depleted in the lighter isotopes and the other contained heavier chromium isotopes. Isotopic studies indicate these components formed a homogeneous mixture in the early Earth, but they separated during partitioning of the Earth’s core (Fig. IUPAC.24.1) [207] F. Moynier, Q. Z. Yin, E. Schauble. Science331, 1417 (2011)., [208] W. F. McDonough. Science331, 1397 (2011)..
Mobility and toxicity of chromium metal depend largely on the oxidation state of the element. Isotopes of chromium are fractionated by reduction-oxidation (redox) chemical reactions. The isotopic composition has been used to trace the origin of the element in the environment and provide information on reduction-oxidation chemical processes [209] A. S. Ellis, T. M. Johnson, T. D. Bullen. Science295, 2060 (2002)..
Isotopes in Medicine
Stable isotopes of chromium are used to investigate the metabolism of chromium (III), which is an essential nutrient. Chromium stable isotopes (53Cr and 54Cr) have been administered to patients and the relative metabolic activity of each isotope is measured to study insulin function in patients suffering from diabetes (a disease in which the body is unable to produce any or enough insulin, and/or is not able to properly use the insulin that it does produce, resulting in elevated levels of glucose in the blood) [210] H. M. Silver, M. A. Seebeck, R. M. Cowett, K. Y. Patterson, C. Veillon. J. Soc. Gynecol. Investig.4, 254 (1997).. 51Cr and 53Cr have been used to label red blood cells to determine blood volume and life-time of red blood cells in the body [210] H. M. Silver, M. A. Seebeck, R. M. Cowett, K. Y. Patterson, C. Veillon. J. Soc. Gynecol. Investig.4, 254 (1997)..
Chromium forms compounds in oxidation states from negative values in organometallic chemistry to +6, but +3 and +6 dominate common inorganic chemistry. Chromium(III) oxide, Cr₂O₃, is a stable green solid and an important pigment and refractory material. Chromium(VI) oxide, CrO₃, chromates such as potassium chromate, K₂CrO₄, and dichromates such as potassium dichromate, K₂Cr₂O₇, are strong oxidants. Chromium(II) chloride, CrCl₂, is a reducing Cr(II) salt used in specialized synthesis.
All compounds of chromium are colored. The most important chromates are those of sodium and potassium, the dichromates, and the potassium and ammonium chrome alums. The dichromates are used as oxidizing agents in quantitative analysis, also in tanning leather.
Other compounds are of industrial value; lead chromate is chrome yellow, a valued pigment. Chromium compounds are used in the textile industry as mordants, and by the aircraft and other industries for anodizing aluminum.
See more information at the Chromium compound page.
Metallic chromium is not highly reactive in bulk form, but dusts and fumes from welding, grinding, or plating operations can be hazardous. Soluble Cr(VI) compounds are toxic, corrosive, sensitizing, and carcinogenic by inhalation, and they require strict exposure control. Cr(III) compounds are generally less mobile and less toxic, although concentrated salts and fine powders still present chemical and occupational hazards.
Chromium compounds are toxic and should be handled with proper safeguards.
Chromium is a natural trace constituent of rocks, soils, and sediments, commonly associated with ultramafic rocks and chromite minerals. In the environment, Cr(III) tends to form insoluble hydroxides and complexes with organic matter, while Cr(VI) oxyanions are more mobile in oxygenated waters. Industrial releases from plating, tanning, pigment manufacture, and waste disposal have produced localized contamination where redox conditions control persistence and transport.
Chromium is produced chiefly by mining chromite ore and reducing it to ferrochrome for steelmaking. South Africa, Kazakhstan, India, Turkey, and several other countries are important sources of chromite, so supply is tied to ore quality, energy costs, and metallurgical capacity. Demand is dominated by stainless steel production, with smaller markets for chemicals, refractories, and plating. Recycling occurs mainly through stainless steel and alloy scrap, which returns chromium to steel production and reduces dependence on primary ore.
The principal ore is chromite, which is found in Zimbabwe, Russia, New Zealand, Turkey, Iran, Albania, Finland, Democratic Republic of Madagascar, and the Phillippines. The metal is usually produced by reducing the oxide with aluminum.
Chromium is a minor but widespread element in the cosmos, made mainly in massive stars and supernova nucleosynthesis near the iron peak. It is present in the Sun, meteorites, and rocky planetary materials. Isotopic ratios of chromium in meteorites are used in cosmochemistry to trace early Solar System reservoirs and nucleosynthetic contributions.
- The name chromium comes from the Greek word for color, reflecting its vividly colored compounds.
- Ruby owes its red color to trace Cr³⁺ substituting for aluminum in corundum.
- Chrome plating can be decorative, but engineering hard chrome is used mainly for wear resistance.
- Passivation by chromium oxide is the key reason stainless steel does not behave like ordinary carbon steel.
- Lead chromate, PbCrO₄, was once a major yellow pigment but is now restricted in many applications.
- Chromium metal is usually traded through ferrochrome rather than as pure metal.
画像
性質
物理的性質
- 原子半径（経験値）
- 140 pm 全元素の原子半径（経験値）を比較 →
- 共有結合半径
- 139 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
- 189 pm 全元素のファンデルワールス半径を比較 →
- 金属半径
- 119 pm 全元素の金属半径を比較 →
- 密度
- 7150 kg/m³ 全元素の密度を比較 →
- モル体積
- 0.00723 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
- 1906.85 °C 全元素の融点を比較 →
- 沸点
- 2670.85 °C 全元素の沸点を比較 →
- 熱伝導率
- 93.9 W/(m·K) 全元素の熱伝導率を比較 →
- 比熱容量
- 0.449 J/(g·K) 全元素の比熱容量を比較 →
- モル熱容量
- 23.35 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）
- 1.66 全元素の電気陰性度（Pauling）を比較 →
- 電気陰性度（Allen）
- 1.65
- 電子親和力
- 0.675 eV
- 第1イオン化エネルギー
- 6.76651 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
- 16.486362 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
- 30.959107 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
- 49.160169 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
- 69.460239 eV 全元素の第5イオン化エネルギーを比較 →
- 酸化数
- −4, −2, −1, 0, +1, +2, +3, +4, +5, +6 全元素の酸化数を比較 →
- 価電子
- 6 全元素の価電子を比較 →
- 電子配置
- [Ar] 3d5 4s1
熱力学的性質
- 融解熱
- 0.21246826 eV 全元素の融解熱を比較 →
- 蒸発熱
- 3.518682 eV 全元素の蒸発熱を比較 →
- 昇華熱
- 4.119811 eV
- 原子化熱
- 4.119811 eV
- 原子化エンタルピー
- 4.119604 eV
原子核
- 陽子数
- 24 全元素の陽子数を比較 →
- 中性子数
- 28 全元素の中性子数を比較 →
- 既知の同位体
- 30 全元素の既知の同位体を比較 →
- 安定同位体
- 3 全元素の安定同位体を比較 →
- 最も安定な同位体
- Cr-52
- 発見年
- 1797
存在度
- 存在度（地殻）
- 102 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
- 288 pm
電子構造
- 各電子殻の電子数
- 2, 8, 13, 1 全元素の各電子殻の電子数を比較 →
識別子
- CAS登録番号
- 7440-47-3 全元素のCAS登録番号を比較 →
- 項記号
- 7S3
- InChI
- InChI=1S/Cr
- InChI Key
- VYZAMTAEIAYCRO-UHFFFAOYSA-N
電子配置 測定値
Cr: 3d⁵ 4s¹[Ar] 3d⁵ 4s¹1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹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 |
|---|---|---|---|
| 52 安定 | 51.94050623 ± 0.00000063 | 83.7890% | 安定 |
| 53 安定 | 52.94064815 ± 0.00000062 | 9.5010% | 安定 |
| 54 安定 | 53.93887916 ± 0.00000061 | 2.3650% | 安定 |
相／状態
理由: 融点（1906.85 °C）より1881.8 °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
原子スペクトル
全24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 |
|---|---|---|---|---|
| Cr I | 0 | 4369 | 527 | 4369 |
| Cr II | +1 | 5370 | 92 | 5370 |
| Cr III | +2 | 136 | 0 | 0 |
| Cr IV | +3 | 188 | 102 | 102 |
| Cr V | +4 | 193 | 104 | 193 |
| Cr VI | +5 | 102 | 26 | 102 |
| Cr VII | +6 | 143 | 4 | 143 |
| Cr VIII | +7 | 36 | 9 | 36 |
| Cr IX | +8 | 58 | 18 | 58 |
| Cr X | +9 | 75 | 46 | 75 |
準位データの収録状況 ?
| イオン | 電荷 | 準位 |
|---|---|---|
| Cr I | 0 | 659 |
| Cr II | +1 | 914 |
| Cr III | +2 | 215 |
| Cr IV | +3 | 155 |
| Cr V | +4 | 47 |
| Cr VI | +5 | 63 |
| Cr VII | +6 | 66 |
| Cr VIII | +7 | 34 |
| Cr IX | +8 | 49 |
| Cr X | +9 | 39 |
イオン半径
| 電荷 | 配位 | スピン | 半径 |
|---|---|---|---|
| +2 | 6 | low | 73 pm |
| +2 | 6 | high | 80 pm |
| +3 | 6 | データなし | 61.5 pm |
| +4 | 4 | データなし | 41 pm |
| +4 | 6 | データなし | 55.00000000000001 pm |
| +5 | 4 | データなし | 34.5 pm |
| +5 | 6 | データなし | 49 pm |
| +5 | 8 | データなし | 56.99999999999999 pm |
| +6 | 4 | データなし | 26 pm |
| +6 | 6 | データなし | 44 pm |
化合物
同位体 (3)
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 | 崩壊形式 | |
|---|---|---|---|---|---|
| 52 安定 | 51.94050623 ± 0.00000063 | 83.7890% ± 0.0180% | 安定 | stable | |
| 53 安定 | 52.94064815 ± 0.00000062 | 9.5010% ± 0.0170% | 安定 | stable | |
| 54 安定 | 53.93887916 ± 0.00000061 | 2.3650% ± 0.0070% | 安定 | stable |
スペクトル線
全2531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 | |
|---|---|---|---|---|---|---|---|
| 540.978408 nm | 8500 | Cr I | emission | 3d4.4s2 a 5D → 3d5.(6S).4p z 5P* | 測定値 | NIST | |
| 534.57965 nm | 5100 | Cr I | emission | 3d4.4s2 a 5D → 3d5.(6S).4p z 5P* | 測定値 | NIST | |
| 529.827202 nm | 3540 | Cr I | emission | 3d4.4s2 a 5D → 3d5.(6S).4p z 5P* | 測定値 | NIST | |
| 435.17622 nm | 3500 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5F* | 測定値 | NIST | |
| 534.83147 nm | 3200 | Cr I | emission | 3d4.4s2 a 5D → 3d5.(6S).4p z 5P* | 測定値 | NIST | |
| 434.450128 nm | 3100 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5F* | 測定値 | NIST | |
| 433.944609 nm | 2600 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5F* | 測定値 | NIST | |
| 526.415341 nm | 2600 | Cr I | emission | 3d4.4s2 a 5D → 3d5.(6S).4p z 5P* | 測定値 | NIST | |
| 464.616212 nm | 2400 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) y 5P* | 測定値 | NIST | |
| 529.669109 nm | 2100 | Cr I | emission | 3d4.4s2 a 5D → 3d5.(6S).4p z 5P* | 測定値 | NIST | |
| 391.915844 nm | 2030 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5D* | 測定値 | NIST | |
| 433.755701 nm | 1900 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5F* | 測定値 | NIST | |
| 740.01798 nm | 1900 | Cr I | emission | 3d5.(6S).4p z 7P* → 3d5.(6S).5s e 7S | 測定値 | NIST | |
| 465.215743 nm | 1750 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) y 5P* | 測定値 | NIST | |
| 435.962444 nm | 1420 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5F* | 測定値 | NIST | |
| 437.127465 nm | 1400 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5F* | 測定値 | NIST | |
| 735.58903 nm | 1400 | Cr I | emission | 3d5.(6S).4p z 7P* → 3d5.(6S).5s e 7S | 測定値 | NIST | |
| 461.612404 nm | 1360 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) y 5P* | 測定値 | NIST | |
| 390.875593 nm | 1310 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5D* | 測定値 | NIST | |
| 449.685195 nm | 1300 | Cr I | emission | 3d5.(6S).4s a 5S → 3d4.(5D).4s.4p.(3P*) y 5P* | 測定値 | NIST | |
| 524.756509 nm | 1250 | Cr I | emission | 3d4.4s2 a 5D → 3d5.(6S).4p z 5P* | 測定値 | NIST | |
| 460.074835 nm | 1190 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) y 5P* | 測定値 | NIST | |
| 433.971051 nm | 1120 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5F* | 測定値 | NIST | |
| 462.617342 nm | 1100 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) y 5P* | 測定値 | NIST | |
| 435.104951 nm | 1080 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5F* | 測定値 | NIST | |
| 438.4975 nm | 1060 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5F* | 測定値 | NIST | |
| 526.571497 nm | 1050 | Cr I | emission | 3d4.4s2 a 5D → 3d5.(6S).4p z 5P* | 測定値 | NIST | |
| 452.64538 nm | 960 | Cr I | emission | 3d5.(4G).4s a 5G → 3d5.(4G).4p z 5G* | 測定値 | NIST | |
| 454.595302 nm | 930 | Cr I | emission | 3d5.(6S).4s a 5S → 3d4.(5D).4s.4p.(3P*) y 5P* | 測定値 | NIST | |
| 532.832346 nm | 930 | Cr I | emission | 3d5.(6S).4p z 7P* → 3d5.(6S).4d e 7D | 測定値 | NIST | |
| 388.32867 nm | 910 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5D* | 測定値 | NIST | |
| 392.86372 nm | 880 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5D* | 測定値 | NIST | |
| 388.521354 nm | 810 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5D* | 測定値 | NIST | |
| 746.23079 nm | 800 | Cr I | emission | 3d5.(6S).4p z 7P* → 3d5.(6S).5s e 7S | 測定値 | NIST | |
| 453.073802 nm | 770 | Cr I | emission | 3d5.(4G).4s a 5G → 3d5.(4G).4p z 5G* | 測定値 | NIST | |
| 388.679508 nm | 740 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5D* | 測定値 | NIST | |
| 392.102067 nm | 740 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5D* | 測定値 | NIST | |
| 394.148757 nm | 720 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5D* | 測定値 | NIST | |
| 697.83983 nm | 640 | Cr I | emission | 3d4.(5D).4s.4p.(3P*) y 7P* → 3d5.(6S).4d e 7D | 測定値 | NIST | |
| 396.3684 nm | 620 | Cr I | emission | 3d5.(4G).4s a 5G → 3d5.(4G).4p y 5H* | 測定値 | NIST | |
| 453.569676 nm | 600 | Cr I | emission | 3d5.(4G).4s a 5G → 3d5.(4G).4p z 5G* | 測定値 | NIST | |
| 390.290908 nm | 590 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) z 5D* | 測定値 | NIST | |
| 455.864413 nm | 590 | Cr II | emission | 3d5 b 4F → 3d4.(5D).4p z 4D* | 測定値 | NIST | |
| 461.335727 nm | 590 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) y 5P* | 測定値 | NIST | |
| 396.974253 nm | 570 | Cr I | emission | 3d5.(4G).4s a 5G → 3d5.(4G).4p y 5H* | 測定値 | NIST | |
| 458.004789 nm | 560 | Cr I | emission | 3d5.(6S).4s a 5S → 3d4.(5D).4s.4p.(3P*) y 5P* | 測定値 | NIST | |
| 530.074563 nm | 530 | Cr I | emission | 3d4.4s2 a 5D → 3d5.(6S).4p z 5P* | 測定値 | NIST | |
| 397.665859 nm | 520 | Cr I | emission | 3d5.(4G).4s a 5G → 3d5.(4G).4p y 5H* | 測定値 | NIST | |
| 454.04987 nm | 500 | Cr I | emission | 3d5.(4G).4s a 5G → 3d5.(4G).4p z 5G* | 測定値 | NIST | |
| 459.139098 nm | 490 | Cr I | emission | 3d4.4s2 a 5D → 3d4.(5D).4s.4p.(3P*) y 5P* | 測定値 | NIST |
詳細な性質
共有結合半径（詳細）
- 共有結合半径（Pyykkö）
- 122 pm
- 共有結合半径（Pyykkö、二重結合）
- 111 pm
- 共有結合半径（Pyykkö、三重結合）
- 103 pm
- 共有結合半径（Bragg）
- 140 pm
ファンデルワールス半径
- Batsanov
- 205 pm
- Alvarez
- 245 pm
- UFF
- 302.3 pm
- MM3
- 225 pm
原子半径と金属半径
- 原子半径（Rahm）
- 233 pm
- 金属半径（C12）
- 128 pm
番号付けの尺度
- Mendeleev
- 51
- Pettifor
- 57
- Glawe
- 55
電気陰性度の尺度
- Ghosh
- 0
- Miedema
- 5
- Gunnarsson–Lundqvist
- 4
- Robles–Bartolotti
- 2
分極率と分散
- 双極子分極率
- 83 a.u.
- 双極子分極率（不確かさ）
- 12 a.u.
- C₆
- 602 Ha·Bohr6
- C₆ (Gould–Bučko)
- 709 Ha·Bohr6
化学親和力
- プロトン親和力
- 791.3 kJ/mol
- 気相塩基性
- 768.4 kJ/mol
ミーデマパラメータ
- ミーデマモル体積
- 7.23 cm3/mol
- ミーデマ電子密度
- 5
供給リスクと経済性
- 生産集中度
- 37
- 相対供給リスク
- 6
- 埋蔵量の分布
- 46
- 政治的安定性（最大生産国）
- 44
- 政治的安定性（最大埋蔵国）
- 62
相転移と同素体
| 融点 | 2180.15 K |
| 沸点 | 2944.15 K |
酸化数の分類
専門参考データ
遮蔽定数 (7)
| n | 軌道 | σ |
|---|---|---|
| 1 | s | 0.5862 |
| 2 | p | 3.9248 |
| 2 | s | 7.0162 |
| 3 | d | 14.2434 |
| 3 | p | 12.534 |
| 3 | s | 11.6322 |
| 4 | s | 18.8668 |
結晶半径の詳細 (10)
| 電荷 | CN | スピン | rcrystal (pm) | 由来 |
|---|---|---|---|---|
| 2 | VI | LS | 87 | estimated, |
| 2 | VI | HS | 94 | from r^3 vs V plots, |
| 3 | VI | 75.5 | from r^3 vs V plots, | |
| 4 | IV | 55 | ||
| 4 | VI | 69 | from r^3 vs V plots, | |
| 5 | IV | 48.5 | from r^3 vs V plots, | |
| 5 | VI | 63 | estimated, from r^3 vs V plots, | |
| 5 | VIII | 71 | ||
| 6 | IV | 40 | ||
| 6 | VI | 58 | calculated, |
同位体の崩壊形式 (52)
| 同位体 | モード | 強度 |
|---|---|---|
| 41 | p | — |
| 42 | B+ | 100% |
| 42 | B+p | 94.4% |
| 42 | 2p | — |
| 43 | B+ | 100% |
| 43 | B+p | 79.3% |
| 43 | 2p | 11.6% |
| 43 | 3p | 0.1% |
| 43 | B+A | — |
| 44 | B+ | 100% |
X線散乱因子 (751)
| エネルギー (eV) | f₁ | f₂ |
|---|---|---|
| 0.42 | -0.0076 | 0.02756 |
| 0.46 | -0.01 | 0.03022 |
| 0.5 | -0.0123 | 0.03301 |
| 0.54 | -0.0148 | 0.03586 |
| 0.58 | -0.0176 | 0.03897 |
| 0.62 | -0.0202 | 0.04225 |
| 0.66 | -0.0225 | 0.04515 |
| 0.7 | -0.0257 | 0.04771 |
| 0.74 | -0.0292 | 0.05056 |
| 0.78 | -0.0332 | 0.05331 |
追加データ
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
1.02×102 milligrams per kilogram
参考文献 (1)
- [5] Chromium https://education.jlab.org/itselemental/ele024.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
3×10-4 milligrams per liter
参考文献 (1)
- [5] Chromium https://education.jlab.org/itselemental/ele024.html
Sources
Sources of this element.
The principal ore is chromite, which is found in Zimbabwe, Russia, New Zealand, Turkey, Iran, Albania, Finland, Democratic Republic of Madagascar, and the Phillippines. The metal is usually produced by reducing the oxide with aluminum.
参考文献 (1)
- [6] Chromium https://periodic.lanl.gov/24.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 Chromium.
The element property data was retrieved from publications.