Calcium (Ca)
alkaline-earth-metalSolid
標準原子量
40.078 u電子配置
[Ar] 4s2融点
841.85 °C沸点
1483.85 °C密度
1540 kg/m³酸化数
+1, +2電気陰性度（Pauling）
1第1イオン化エネルギー
6.113155 eV発見年
1808原子半径
180 pm詳細
Calcium is an alkaline earth metal and the fifth most abundant element in Earth’s crust by mass. It is highly reactive as a free metal but widespread in stable minerals, especially carbonates, sulfates, phosphates, and silicates. Calcium chemistry is dominated by the Ca²⁺ ion, which is hard, strongly hydrated, and central to limestone formation, cement chemistry, seawater buffering, bones, teeth, shells, and many cellular signaling processes.
The metal has a silvery color, is rather hard, and is prepared by electrolysis of fused chloride and calcium fluoride (to lower the melting point).
Chemically it is one of the alkaline earth elements; it readily forms a white coating of nitride in air, reacts with water, burns with a yellow-red flame.
The name derives from the Latin calx for "lime" (CaO) or "limestone" (CaCO3) in which it was found. It was first isolated by British chemist Humphry Davy in 1808 with help from the Swedish chemist Jöns Jacob Berzelius and the Swedish court physician M. M. af Pontin.
Although calcium is the fifth most abundant element in the earth's crust, it is never found free in nature since it easily forms compounds by reacting with oxygen and water. Metallic calcium was first isolated by Sir Humphry Davy in 1808 through the electrolysis of a mixture of lime (CaO) and mercuric oxide (HgO). Today, metallic calcium is obtained by displacing calcium atoms in lime with atoms of aluminum in hot, low-pressure containers. About 4.2% of the earth's crust is composed of calcium.
From the Latin word calx, lime. Though lime was prepared by the Romans in the first century under the name calx, the metal was not discovered until 1808. After learning that Berzelius and Pontin prepared calcium amalgam by electrolyzing lime in mercury, Davy was able to isolate the impure metal.
Pure calcium is a silvery gray metal that is softer than many structural metals and can be cut when freshly prepared. It tarnishes in air as oxide, nitride, and hydroxide films form, and it reacts slowly with water, releasing H₂. It is normally stored protected from moisture and air.
Metallic calcium is used on a modest scale as a reducing agent, deoxidizer, desulfurizer, and alloying additive, especially in specialty metallurgy and in some lead and aluminum alloys. Much larger practical use is tied to calcium-containing materials: limestone, lime, gypsum, and calcium silicates are essential in cement, glass, steelmaking fluxes, soil amendment, water treatment, and construction. Calcium compounds are also used in food, pharmaceuticals, paper, plastics, and flue-gas treatment.
Due to its high reactivity with common materials, there is very little demand for metallic calcium. It is used in some chemical processes to refine thorium, uranium and zirconium. Calcium is also used to remove oxygen, sulfur and carbon from certain alloys. Calcium can be alloyed with aluminum, beryllium, copper, lead and magnesium. Calcium is also used in vacuum tubes as a getter, a material that combines with and removes trace gases from vacuum tubes.
Calcium carbonate (CaCO3) is one of the common compounds of calcium. It is heated to form quicklime (CaO) which is then added to water (H2O). This forms another material known as slaked lime (Ca(OH)2) which is an inexpensive base material used throughout the chemical industry. Chalk, marble and limestone are all forms of calcium carbonate. Calcium carbonate is used to make white paint, cleaning powder, toothpaste and stomach antacids, among other things. Other common compounds of calcium include: calcium sulfate (CaSO4), also known as gypsum, which is used to make dry wall and plaster of Paris, calcium nitrate (Ca(NO3)2), a naturally occurring fertilizer and calcium phosphate (Ca3(PO4)2), the main material found in bones and teeth.
The metal is used as a reducing agent in preparing other metals such as thorium, uranium, zirconium, etc., and is used as a deoxidizer, desulfurizer, or decarburizer for various ferrous and nonferrous alloys. It is also used as an alloying agent for aluminum, beryllium, copper, lead, and magnesium alloys, and serves as a "getter" for residual gases in vacuum tubes, etc.
Isotopes in Earth/Planetary Science
Molecules, atoms, and ions of the stable isotopes of calcium 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 (Fig. IUPAC.20.1). The isotope-amount ratio n(44Ca)/n(40Ca) is used to quantify the calcium cycle (sources and sinks of calcium) in the ocean. Calcium isotopes fractionate (separate) in terrestrial and marine environments owing to biological and inorganic processes, which discriminate against heavy calcium isotopes. The calcification process controls the removal of calcium from the ocean, which is mostly balanced by hydrothermal and riverine calcium input. Calcium has a long residence time, symbol τ, in seawater (τCa about 1 to 2 million years) relative to the short mixing time of the global ocean (about 1000 years), which has allowed the calcium isotopic composition of modern seawater to homogenize globally. This was likely the case in the geological past as well, which makes the n(44Ca)/n(40Ca) ratio useful when quantifying the oceanic calcium cycle [182] P. Zhu, J. D. Macdougall. Geochim. Cosmochim. Acta62, 1691 (1998)., [183] J. Farkaš, D. Buhl, J. Blenkinsop, J. Veizer. Earth Planet. Sci. Lett.253, 96 (2007).. The isotope-amount ratio n(44Ca)/n(40Ca) has been used to trace sources of calcium in soil and river water [184] T. Walczyk. Fresenius J. Anal. Chem.370, 444 (2001).. The isotope-amount ratio n(44Ca)/n(40Ca) ratio of calcium carbonate may serve as a paleothermometer to determine seawater temperatures in the past, making use of the temperature-dependent isotopic fractionation between 40Ca and 44Ca [185] E. M. Griffith, E. A. Schauble, T. D. Bullen, A. Paytan. Geochim. Cosmochim. Acta72, 5641 (2008)., [186] T. F. Nägler, A. Eisenhauer, A. Müller, C. Hemleben, J. Kramers. Geochem. Geophy. Geosy.1, 1052 (2000)..
The radioactive isotope 45Ca (half-life of 163 days) is used to study calcium behavior in soils, detergents, water-purification systems, and glassy materials. 45Ca is introduced into a system and monitored to measure various types of calcium responses within the system and to investigate how calcium of one matrix may interact with another (i.e. calcium of soil mixing with that of fertilizers). 45Ca has been used to investigate the transport of contaminants in groundwater through the unsaturated zone [187] P. Nkedi-Kizza, M. L. Brusseau, P. S. C. Rao, A. G. Hornsby. Environ. Sci. Technol.23, 814 (1989)..
Isotopes in Medicine
Stable isotopes of calcium (42Ca, 44Ca, 46Ca, and 48Ca) and radioisotopes of calcium (45Ca and 47Ca, with a half-life of 109 h) can be used for tracing calcium uptake, utilization, and excretion in the body. For example, most of our knowledge on the efficiency by which calcium is absorbed in the intestine (bioavailability) comes from studies in which calcium in the diet was labeled with stable or radioactive isotopes. In such studies, the isotope-labeled food is ingested and fecal matter tested for the presence and quantity of unabsorbed isotope. When coupling oral ingestion of food labeled with one calcium isotope with an intravenous injection of a second calcium isotope, this technique can be used as a means to measure calcium absorption within the body by measuring excretion of both tracers in the urine. In a similar fashion, dietary absorption of magnesium and zinc can be studied [184] T. Walczyk. Fresenius J. Anal. Chem.370, 444 (2001)., [188] S. J. Adelstein, F. J. Manning. Isotopes for Medicine and the Life Sciences, pp. 20–25, National Academy Press, Washington DC (1995)..
Stable and radioactive isotopes are used in biomedical research and clinical practice to study disorders associated with calcium metabolism, in particular in relation to bone health and calcium accumulation in body tissues (vascular calcification, kidney stone formation). Stable isotope tracers have been used successfully to study bone calcium balance during space-flight and in-bed-rest studies. A long-living calcium radioisotope (41Ca), with a half-life of 9.9×104 years, has been used successfully for labeling of bone calcium to measure bone calcium turnover via urinary excretion of the tracer [189] D. Elmore, M. H. Bhattacharyya, N. Sacco-Gibson, D. P. Peterson. Nucl. Instrum. Methods Phys. Res. Sect. B52, 531 (1990)..
Calcium nearly always occurs in the +2 oxidation state, forming ionic or partly ionic compounds with high lattice energies. Important minerals and materials include calcium carbonate (CaCO₃), calcium sulfate dihydrate (CaSO₄·2H₂O), calcium oxide (CaO), calcium hydroxide (Ca(OH)₂), calcium chloride (CaCl₂), and calcium phosphate phases such as hydroxyapatite (Ca₅(PO₄)₃OH). Calcium hydride (CaH₂) is a useful drying and hydrogen-generating reagent. Calcium forms organometallic reagents, but they are less common than magnesium analogues.
Its natural and prepared compounds are widely used. Quicklime (CaO), which is made by heating limestone that is changed into slaked lime by carefully adding water, is the great base of chemical refinery with countless uses.
When mixed with sand, it hardens mortar and plaster by taking up carbon dioxide from the air. Calcium from limestone is an important element in Portland cement.
Solubility of the carbonate in water containing carbon dioxide is high, which causes the formation of caves with stalactites and stalagmites and is responsible for hardness in water. Other important compounds are the carbide, chloride, cyanamide, hypochlorite, nitrate, and sulfide.
See more information at the Calcium compound page.
Calcium is an essential nutrient, but concentrated calcium metal and many reactive calcium compounds require care. The metal reacts with water and acids to produce flammable H₂ and caustic solutions. Calcium oxide (CaO) and calcium hydroxide (Ca(OH)₂) are strongly alkaline and can burn skin, eyes, and respiratory tissue. Soluble calcium salts are generally of low acute toxicity, although excessive intake or exposure can disturb normal mineral balance. Dust from limestone, cement, or gypsum is mainly a particulate and alkalinity hazard.
Calcium is a major participant in the rock, water, and biological cycles. Weathering releases Ca²⁺ from silicate and carbonate minerals, rivers carry it to lakes and oceans, and it is removed by carbonate precipitation, shell formation, and sedimentation. Calcium affects soil structure and pH buffering and is an essential macronutrient for plants and animals. Acid deposition can leach calcium from soils and alter forest and freshwater ecosystems.
The calcium economy is dominated not by the metal but by abundant minerals and processed materials. Limestone and gypsum are quarried on large scales, while lime is produced by heating calcium carbonate (CaCO₃) to make calcium oxide (CaO). Portland cement production consumes major quantities of calcium-rich feedstocks. Metallic calcium is a smaller specialty product, commonly made by electrolysis or metallothermic reduction routes and used where its strong reducing and scavenging properties justify handling costs. Recycling is indirect, mainly through construction materials, steel slags, and industrial by-products rather than recovery of elemental calcium.
Calcium, a metallic element, is fifth in abundance in the earth's crust, of which it forms more than 3%. It is an essential constituent of leaves, bones, teeth, and shells. Never found in nature uncombined, it occurs abundantly as limestone, gypsum, and fluorite. Apatite is the fluorophosphate or chlorophosphate of calcium.
Calcium is a common cosmic element produced chiefly in massive stars during advanced nuclear burning and dispersed by supernovae. Its spectral lines are prominent in many stars and in interstellar gas. In rocky planets it is concentrated into silicate and carbonate minerals, while in meteorites it occurs in calcium-aluminum-rich inclusions that record very early high-temperature solids in the Solar System.
- Calcium metal is less dense than aluminum but much more chemically reactive.
- The Ca²⁺ ion gives brick-red to orange-red colors in flame tests.
- Hard water is often hard because it contains dissolved calcium and magnesium ions.
- Calcium carbonate can exist as calcite, aragonite, or vaterite, with calcite the most stable at surface conditions.
- Calcium signaling in cells works because free Ca²⁺ concentrations are kept very low in the cytosol.
画像
性質
物理的性質
- 原子半径（経験値）
- 180 pm 全元素の原子半径（経験値）を比較 →
- 共有結合半径
- 176 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
- 231 pm 全元素のファンデルワールス半径を比較 →
- 金属半径
- 174 pm 全元素の金属半径を比較 →
- 密度
- 1540 kg/m³ 全元素の密度を比較 →
- モル体積
- 0.0299 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
- 841.85 °C 全元素の融点を比較 →
- 沸点
- 1483.85 °C 全元素の沸点を比較 →
- 比熱容量
- 0.647 J/(g·K) 全元素の比熱容量を比較 →
- モル熱容量
- 25.929 J/(mol·K) 全元素のモル熱容量を比較 →
- 結晶構造
- 面心立方構造 全元素の結晶構造を比較 →
化学的性質
- 電気陰性度（Pauling）
- 1 全元素の電気陰性度（Pauling）を比較 →
- 電気陰性度（Allen）
- 1.034
- 電子親和力
- 0.0245 eV
- 第1イオン化エネルギー
- 6.113155 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
- 11.87176 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
- 50.913335 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
- 67.273432 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
- 84.34029 eV 全元素の第5イオン化エネルギーを比較 →
- 酸化数
- +1, +2 全元素の酸化数を比較 →
- 価電子
- 2 全元素の価電子を比較 →
- 電子配置
- [Ar] 4s2
熱力学的性質
- 融解熱
- 0.08851117 eV 全元素の融解熱を比較 →
- 蒸発熱
- 1.603358 eV 全元素の蒸発熱を比較 →
- 昇華熱
- 1.846919 eV
- 原子化熱
- 1.846919 eV
- 原子化エンタルピー
- 1.842773 eV
原子核
- 陽子数
- 20 全元素の陽子数を比較 →
- 中性子数
- 24 全元素の中性子数を比較 →
- 既知の同位体
- 29 全元素の既知の同位体を比較 →
- 安定同位体
- 4 全元素の安定同位体を比較 →
- 最も安定な同位体
- Ca-44
- 発見年
- 1808
存在度
- 存在度（地殻）
- 4.15e+4 mg/kg 全元素の存在度（地殻）を比較 →
- 存在度（海洋）
- 412 mg/L 全元素の存在度（海洋）を比較 →
結晶構造
- 格子定数a
- 558 pm
電子構造
- 各電子殻の電子数
- 2, 8, 8, 2 全元素の各電子殻の電子数を比較 →
識別子
- CAS登録番号
- 7440-70-2 全元素のCAS登録番号を比較 →
- 項記号
- 1S0
- InChI
- InChI=1S/Ca
- InChI Key
- OYPRJOBELJOOCE-UHFFFAOYSA-N
電子配置 測定値
Ca: 4s²[Ar] 4s²1s² 2s² 2p⁶ 3s² 3p⁶ 4s²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 |
|---|---|---|---|
| 42 安定 | 41.95861783 ± 0.00000016 | 0.6470% | 安定 |
| 43 安定 | 42.95876644 ± 0.00000024 | 0.1350% | 安定 |
| 44 安定 | 43.95548156 ± 0.00000035 | 2.0860% | 安定 |
| 46 安定 | 45.953689 ± 0.0000024 | 0.0040% | 安定 |
相／状態
理由: 融点（841.85 °C）より816.9 °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20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 |
|---|---|---|---|---|
| Ca I | 0 | 206 | 136 | 137 |
| Ca II | +1 | 149 | 99 | 99 |
| Ca III | +2 | 676 | 530 | 676 |
| Ca IV | +3 | 40 | 3 | 3 |
| Ca V | +4 | 53 | 18 | 18 |
| Ca VI | +5 | 20 | 18 | 20 |
| Ca VII | +6 | 18 | 18 | 18 |
| Ca VIII | +7 | 6 | 6 | 6 |
| Ca IX | +8 | 26 | 26 | 26 |
| Ca X | +9 | 25 | 25 | 25 |
準位データの収録状況 ?
| イオン | 電荷 | 準位 |
|---|---|---|
| Ca I | 0 | 787 |
| Ca II | +1 | 72 |
| Ca III | +2 | 182 |
| Ca IV | +3 | 71 |
| Ca V | +4 | 40 |
| Ca VI | +5 | 32 |
| Ca VII | +6 | 27 |
| Ca VIII | +7 | 38 |
| Ca IX | +8 | 72 |
| Ca X | +9 | 52 |
イオン半径
| 電荷 | 配位 | スピン | 半径 |
|---|---|---|---|
| +2 | 6 | データなし | 100 pm |
| +2 | 7 | データなし | 106 pm |
| +2 | 8 | データなし | 112.00000000000001 pm |
| +2 | 9 | データなし | 118 pm |
| +2 | 10 | データなし | 123 pm |
| +2 | 12 | データなし | 134 pm |
化合物
同位体 (4)
| 質量数 | 原子質量（u） | 天然存在比 | 半減期 | 崩壊形式 | |
|---|---|---|---|---|---|
| 42 安定 | 41.95861783 ± 0.00000016 | 0.6470% ± 0.0230% | 安定 | stable | |
| 43 安定 | 42.95876644 ± 0.00000024 | 0.1350% ± 0.0100% | 安定 | stable | |
| 44 安定 | 43.95548156 ± 0.00000035 | 2.0860% ± 0.1100% | 安定 | stable | |
| 46 安定 | 45.953689 ± 0.0000024 | 0.0040% ± 0.0030% | 安定 | stable |
スペクトル線
全247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 | |
|---|---|---|---|---|---|---|---|
| 408.1762 nm | 1000 | Ca III | emission | 3s2.3p5.4s 1P* → 3s2.3p5.4p 3S | 測定値 | NIST | |
| 449.9885 nm | 1000 | Ca III | emission | 3s2.3p5.(2P*<1/2>).4d 2[5/2]* → 3s2.3p5.(2P*<1/2>).4f 2[7/2] | 測定値 | NIST | |
| 420.7216 nm | 800 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[3/2]* → 3s2.3p5.(2P*<3/2>).4f 2[5/2] | 測定値 | NIST | |
| 430.2803 nm | 800 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[7/2]* → 3s2.3p5.(2P*<3/2>).4f 2[9/2] | 測定値 | NIST | |
| 439.9584 nm | 800 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[7/2]* → 3s2.3p5.(2P*<3/2>).4f 2[9/2] | 測定値 | NIST | |
| 423.3736 nm | 700 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4f 2[9/2] → 3s2.3p5.(2P*<3/2>).5g 2[11/2]* | 測定値 | NIST | |
| 440.6286 nm | 700 | Ca III | emission | 3s2.3p5.(2P*<1/2>).4d 2[5/2]* → 3s2.3p5.(2P*<1/2>).4f 2[7/2] | 測定値 | NIST | |
| 451.6586 nm | 700 | Ca III | emission | 3s2.3p5.(2P*<1/2>).4d 2[3/2]* → 3s2.3p5.(2P*<1/2>).4f 2[5/2] | 測定値 | NIST | |
| 457.2125 nm | 700 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[5/2]* → 3s2.3p5.(2P*<3/2>).4f 2[7/2] | 測定値 | NIST | |
| 424.0742 nm | 600 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4f 2[9/2] → 3s2.3p5.(2P*<3/2>).5g 2[11/2]* | 測定値 | NIST | |
| 443.129 nm | 600 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[5/2]* → 3s2.3p5.(2P*<3/2>).4f 2[7/2] | 測定値 | NIST | |
| 415.3566 nm | 500 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[1/2]* → 3s2.3p5.(2P*<3/2>).4f 2[3/2] | 測定値 | NIST | |
| 418.42 nm | 500 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[1/2]* → 3s2.3p5.(2P*<3/2>).4f 2[3/2] | 測定値 | NIST | |
| 428.4388 nm | 500 | Ca III | emission | 3s2.3p5.(2P*<1/2>).4f 2[7/2] → 3s2.3p5.(2P*<1/2>).5g 2[9/2]* | 測定値 | NIST | |
| 432.9182 nm | 490 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4f 2[7/2] → 3s2.3p5.(2P*<3/2>).5g 2[9/2]* | 測定値 | NIST | |
| 433.3566 nm | 480 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4f 2[7/2] → 3s2.3p5.(2P*<3/2>).5g 2[9/2]* | 測定値 | NIST | |
| 416.4302 nm | 430 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4f 2[3/2] → 3s2.3p5.(2P*<3/2>).5g 2[5/2]* | 測定値 | NIST | |
| 417.565 nm | 410 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[7/2]* → 3s2.3p5.(2P*<3/2>).4f 2[7/2] | 測定値 | NIST | |
| 427.189 nm | 410 | Ca III | emission | 3s2.3p5.(2P*<1/2>).4f 2[5/2] → 3s2.3p5.(2P*<1/2>).5g 2[7/2]* | 測定値 | NIST | |
| 435.8366 nm | 410 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[3/2]* → 3s2.3p5.(2P*<1/2>).4f 2[5/2] | 測定値 | NIST | |
| 421.3132 nm | 400 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[1/2]* → 3s2.3p5.(2P*<3/2>).4f 2[3/2] | 測定値 | NIST | |
| 413.6247 nm | 390 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4f 2[3/2] → 3s2.3p5.(2P*<3/2>).5g 2[5/2]* | 測定値 | NIST | |
| 427.9722 nm | 360 | Ca III | emission | 3s2.3p5.(2P*<1/2>).4f 2[7/2] → 3s2.3p5.(2P*<1/2>).5g 2[9/2]* | 測定値 | NIST | |
| 430.1494 nm | 290 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[3/2]* → 3s2.3p5.(2P*<3/2>).4f 2[3/2] | 測定値 | NIST | |
| 429.0071 nm | 280 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4f 2[5/2] → 3s2.3p5.(2P*<3/2>).5g 2[7/2]* | 測定値 | NIST | |
| 427.8215 nm | 270 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[7/2]* → 3s2.3p5.(2P*<3/2>).4f 2[7/2] | 測定値 | NIST | |
| 430.101 nm | 240 | Ca III | emission | 3s2.3p5.(2P*<1/2>).4f 2[5/2] → 3s2.3p5.(2P*<1/2>).5g 2[7/2]* | 測定値 | NIST | |
| 393.3663 nm | 230 | Ca II | emission | 3p6.4s 2S → 3p6.4p 2P* | 測定値 | NIST | |
| 394.9609 nm | 230 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[5/2]* → 3s2.3p5.(2P*<1/2>).4f 2[7/2] | 測定値 | NIST | |
| 396.8469 nm | 220 | Ca II | emission | 3p6.4s 2S → 3p6.4p 2P* | 測定値 | NIST | |
| 427.3875 nm | 200 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[7/2]* → 3s2.3p5.(2P*<3/2>).4f 2[7/2] | 測定値 | NIST | |
| 527.1979 nm | 170 | Ca III | emission | 3s2.3p5.(2P*<3/2>).5p 2[5/2] → 3s2.3p5.(2P*<3/2>).5d 2[7/2]* | 測定値 | NIST | |
| 403.8502 nm | 160 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[1/2]* → 3s2.3p5.(2P*<3/2>).4f 2[5/2] | 測定値 | NIST | |
| 382.376 nm | 150 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[7/2]* → 3s2.3p5.(2P*<1/2>).4f 2[7/2] | 測定値 | NIST | |
| 448.4948 nm | 150 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[5/2]* → 3s2.3p5.(2P*<3/2>).4f 2[5/2] | 測定値 | NIST | |
| 470.8836 nm | 150 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[5/2]* → 3s2.3p5.(2P*<3/2>).4f 2[5/2] | 測定値 | NIST | |
| 471.6287 nm | 130 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[5/2]* → 3s2.3p5.(2P*<3/2>).4f 2[9/2] | 測定値 | NIST | |
| 606.9998 nm | 110 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[7/2]* → 3s2.3p5.(2P*<3/2>).5p 2[5/2] | 測定値 | NIST | |
| 524.7373 nm | 100 | Ca III | emission | 3s2.3p5.(2P*<3/2>).5p 2[5/2] → 3s2.3p5.(2P*<3/2>).5d 2[7/2]* | 測定値 | NIST | |
| 393.0884 nm | 90 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[5/2]* → 3s2.3p5.(2P*<1/2>).4f 2[5/2] | 測定値 | NIST | |
| 485.9165 nm | 90 | Ca III | emission | 3s2.3p5.(2P*<3/2>).5p 2[5/2] → 3s2.3p5.(2P*<3/2>).6s 2[3/2]* | 測定値 | NIST | |
| 500.8939 nm | 90 | Ca III | emission | 3s2.3p5.(2P*<3/2>).5p 2[1/2] → 3s2.3p5.(2P*<3/2>).5d 2[1/2]* | 測定値 | NIST | |
| 532.1287 nm | 90 | Ca III | emission | 3s2.3p5.(2P*<3/2>).5p 2[3/2] → 3s2.3p5.(2P*<3/2>).5d 2[5/2]* | 測定値 | NIST | |
| 434.0345 nm | 80 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4f 2[7/2] → 3s2.3p5.(2P*<3/2>).5g 2[7/2]* | 測定値 | NIST | |
| 441.3732 nm | 80 | Ca III | emission | 3s2.3p5.(2P*<1/2>).4d 2[5/2]* → 3s2.3p5.(2P*<1/2>).4f 2[5/2] | 測定値 | NIST | |
| 450.8788 nm | 80 | Ca III | emission | 3s2.3p5.(2P*<1/2>).4d 2[3/2]* → 3s2.3p5.(2P*<1/2>).4f 2[7/2] | 測定値 | NIST | |
| 463.2855 nm | 80 | Ca III | emission | 3s2.3p5.(2P*<1/2>).5p 2[3/2] → 3s2.3p5.(2P*<1/2>).5d 2[3/2]* | 測定値 | NIST | |
| 501.9971 nm | 80 | Ca II | emission | 3p6.5p 2P* → 3p6.6d 2D | 測定値 | NIST | |
| 505.0089 nm | 80 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[3/2]* → 3s2.3p5.(2P*<3/2>).4f 2[5/2] | 測定値 | NIST | |
| 557.0601 nm | 80 | Ca III | emission | 3s2.3p5.(2P*<3/2>).4d 2[3/2]* → 3s2.3p5.(2P*<3/2>).5p 2[3/2] | 測定値 | NIST |
詳細な性質
共有結合半径（詳細）
- 共有結合半径（Pyykkö）
- 171 pm
- 共有結合半径（Pyykkö、二重結合）
- 147 pm
- 共有結合半径（Pyykkö、三重結合）
- 133 pm
- 共有結合半径（Bragg）
- 170 pm
ファンデルワールス半径
- Truhlar
- 231 pm
- Batsanov
- 240 pm
- Alvarez
- 262 pm
- UFF
- 339.9 pm
- MM3
- 281 pm
原子半径と金属半径
- 原子半径（Rahm）
- 270 pm
- 金属半径（C12）
- 197 pm
番号付けの尺度
- Mendeleev
- 7
- Pettifor
- 16
- Glawe
- 16
電気陰性度の尺度
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 3
- Robles–Bartolotti
- 2
分極率と分散
- 双極子分極率
- 160.8 a.u.
- 双極子分極率（不確かさ）
- 4 a.u.
- C₆
- 2163 Ha·Bohr6
- C₆ (Gould–Bučko)
- 2230 Ha·Bohr6
ミーデマパラメータ
- ミーデマモル体積
- 26.2 cm3/mol
- ミーデマ電子密度
- 1
供給リスクと経済性
- 生産集中度
- 65
- 相対供給リスク
- 6
- 政治的安定性（最大生産国）
- 24
相転移と同素体
| 融点 | 1115.15 K |
| 沸点 | 1757.15 K |
酸化数の分類
専門参考データ
遮蔽定数 (6)
| n | 軌道 | σ |
|---|---|---|
| 1 | s | 0.527 |
| 2 | p | 3.9586 |
| 2 | s | 6.2236 |
| 3 | p | 11.3417 |
| 3 | s | 10.3985 |
| 4 | s | 15.602 |
結晶半径の詳細 (6)
| 電荷 | CN | スピン | rcrystal (pm) | 由来 |
|---|---|---|---|---|
| 2 | VI | 114 | ||
| 2 | VII | 120 | ||
| 2 | VIII | 126 | ||
| 2 | IX | 132 | ||
| 2 | X | 137 | calculated, | |
| 2 | XII | 148 | calculated, |
同位体の崩壊形式 (50)
| 同位体 | モード | 強度 |
|---|---|---|
| 33 | p | — |
| 34 | 2p | — |
| 35 | B+ | 100% |
| 35 | B+p | 95.8% |
| 35 | 2p | 4.2% |
| 36 | B+ | 100% |
| 36 | B+p | 51.2% |
| 37 | B+ | 100% |
| 37 | B+p | 76.8% |
| 38 | B+ | 100% |
X線散乱因子 (504)
| エネルギー (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0.0428 |
| 10.1617 | — | 0.04527 |
| 10.3261 | — | 0.04788 |
| 10.4931 | — | 0.05063 |
| 10.6628 | — | 0.05355 |
| 10.8353 | — | 0.05663 |
| 11.0106 | — | 0.05989 |
| 11.1886 | — | 0.06334 |
| 11.3696 | — | 0.06634 |
| 11.5535 | — | 0.06922 |
追加データ
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
4.15×104 milligrams per kilogram
参考文献 (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
4.12×102 milligrams per liter
参考文献 (1)
Sources
Sources of this element.
Calcium, a metallic element, is fifth in abundance in the earth's crust, of which it forms more than 3%. It is an essential constituent of leaves, bones, teeth, and shells. Never found in nature uncombined, it occurs abundantly as limestone, gypsum, and fluorite. Apatite is the fluorophosphate or chlorophosphate of calcium.
参考文献 (1)
- [6] Calcium https://periodic.lanl.gov/20.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 Calcium.
The element property data was retrieved from publications.