Calcium (Ca)
alkaline-earth-metalSolid
标准原子量
40.078 u电子排布
[Ar] 4s2熔点
841.85 °C沸点
1483.85 °C密度
1540 kg/m³氧化态
+1, +2电负性（鲍林）
1第一电离能
6.113155 eV发现年份
1808原子半径
180 pm详细信息
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.
图片
性质
物理性质
- 原子半径（经验值）
- 180 pm 比较所有元素的原子半径（经验值） →
- 共价半径
- 176 pm 比较所有元素的共价半径 →
- 范德华半径
- 231 pm 比较所有元素的范德华半径 →
- 金属半径
- 174 pm 比较所有元素的金属半径 →
- 密度
- 1540 kg/m³ 比较所有元素的密度 →
- 摩尔体积
- 0.0299 L/mol
- 标准温度和压力下的物相
- 固态 比较所有元素的标准温度和压力下的物相 →
- 熔点
- 841.85 °C 比较所有元素的熔点 →
- 沸点
- 1483.85 °C 比较所有元素的沸点 →
- 比热容
- 0.647 J/(g·K) 比较所有元素的比热容 →
- 摩尔热容
- 25.929 J/(mol·K) 比较所有元素的摩尔热容 →
- 晶体结构
- 面心立方 比较所有元素的晶体结构 →
化学性质
- 电负性（鲍林）
- 1 比较所有元素的电负性（鲍林） →
- 电负性（Allen）
- 1.034
- 电子亲和能
- 0.0245 eV
- 第一电离能
- 6.113155 eV 比较所有元素的第一电离能 →
- 第二电离能
- 11.87176 eV 比较所有元素的第二电离能 →
- 第三电离能
- 50.913335 eV 比较所有元素的第三电离能 →
- 第四电离能
- 67.273432 eV 比较所有元素的第四电离能 →
- 第五电离能
- 84.34029 eV 比较所有元素的第五电离能 →
- 氧化态
- +1, +2 比较所有元素的氧化态 →
- 价电子
- 2 比较所有元素的价电子 →
- 电子排布
- [Ar] 4s2
热力学性质
- 熔化热
- 0.08851117 eV 比较所有元素的熔化热 →
- 汽化热
- 1.603358 eV 比较所有元素的汽化热 →
- 升华热
- 1.846919 eV
- 原子化热
- 1.846919 eV
- 原子化焓
- 1.842773 eV
核性质
- 质子
- 20 比较所有元素的质子 →
- 中子
- 24 比较所有元素的中子 →
- 已知同位素
- 29 比较所有元素的已知同位素 →
- 稳定同位素
- 4 比较所有元素的稳定同位素 →
- 最稳定同位素
- Ca-44
- 发现年份
- 1808
丰度
- 丰度（地壳）
- 4.15e+4 mg/kg 比较所有元素的丰度（地壳） →
- 丰度（海洋）
- 412 mg/L 比较所有元素的丰度（海洋） →
晶体结构
- 晶格常数a
- 558 pm
电子结构
- 各电子层电子数
- 2, 8, 8, 2 比较所有元素的各电子层电子数 →
标识符
- CAS登记号
- 7440-70-2 比较所有元素的CAS登记号 →
- 谱项符号
- 1S0
- InChI
- InChI=1S/Ca
- InChI Key
- OYPRJOBELJOOCE-UHFFFAOYSA-N
电子排布 实测值
Ca: 4s²[Ar] 4s²1s² 2s² 2p⁶ 3s² 3p⁶ 4s²原子模型
不同同位素的中子数、质量和稳定性不同，但中性原子的电子排布不变。
原子模型示意图，未按比例绘制。
原子指纹
发射 / 吸收光谱
同位素分布
| 质量数 | 原子质量（u） | 天然丰度 | 半衰期 |
|---|---|---|---|
| 42 稳定 | 41.95861783 ± 0.00000016 | 0.6470% | 稳定 |
| 43 稳定 | 42.95876644 ± 0.00000024 | 0.1350% | 稳定 |
| 44 稳定 | 43.95548156 ± 0.00000035 | 2.0860% | 稳定 |
| 46 稳定 | 45.953689 ± 0.0000024 | 0.0040% | 稳定 |
物相 / 状态
原因: 低于熔点（841.85 °C）816.9 °C
示意图，未按比例绘制
相变点
相变能
在熔点熔化1 mol物质所需的能量
在沸点汽化1 mol物质所需的能量
在升华点升华1 mol物质所需的能量
密度
标准条件下
标准条件下
原子光谱
已显示10项，共20项。 按离子电荷升序排列。
收录谱线 ?
| 离子 | 电荷 | 谱线总数 | 跃迁概率 | 能级标记 |
|---|---|---|---|---|
| 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 |
收录能级 ?
| 离子 | 电荷 | 能级 |
|---|---|---|
| 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 |
离子半径
| 电荷 | 配位 | 自旋 | 半径 |
|---|---|---|---|
| +2 | 6 | 暂无 | 100 pm |
| +2 | 7 | 暂无 | 106 pm |
| +2 | 8 | 暂无 | 112.00000000000001 pm |
| +2 | 9 | 暂无 | 118 pm |
| +2 | 10 | 暂无 | 123 pm |
| +2 | 12 | 暂无 | 134 pm |
化合物
同位素 (4)
| 质量数 | 原子质量（u） | 天然丰度 | 半衰期 | 衰变方式 | |
|---|---|---|---|---|---|
| 42 稳定 | 41.95861783 ± 0.00000016 | 0.6470% ± 0.0230% | 稳定 | stable | |
| 43 稳定 | 42.95876644 ± 0.00000024 | 0.1350% ± 0.0100% | 稳定 | stable | |
| 44 稳定 | 43.95548156 ± 0.00000035 | 2.0860% ± 0.1100% | 稳定 | stable | |
| 46 稳定 | 45.953689 ± 0.0000024 | 0.0040% ± 0.0030% | 稳定 | stable |
谱线
已显示50项，共247项。 默认仅显示具有实测强度的谱线。
| 波长（nm） | 强度 | 电离级 | 类型 | 跃迁 | 准确度 | 来源 | |
|---|---|---|---|---|---|---|---|
| 408.1762 nm | 1000 | Ca III | emission | 3s2.3p5.4s 1P* → 3s2.3p5.4p 3S | 实测值 | 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] | 实测值 | 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] | 实测值 | 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] | 实测值 | 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] | 实测值 | 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]* | 实测值 | 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] | 实测值 | 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] | 实测值 | 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] | 实测值 | 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]* | 实测值 | 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] | 实测值 | 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] | 实测值 | 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] | 实测值 | 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]* | 实测值 | 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]* | 实测值 | 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]* | 实测值 | 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]* | 实测值 | 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] | 实测值 | 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]* | 实测值 | 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] | 实测值 | 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] | 实测值 | 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]* | 实测值 | 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]* | 实测值 | 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] | 实测值 | 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]* | 实测值 | 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] | 实测值 | 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]* | 实测值 | NIST | |
| 393.3663 nm | 230 | Ca II | emission | 3p6.4s 2S → 3p6.4p 2P* | 实测值 | 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] | 实测值 | NIST | |
| 396.8469 nm | 220 | Ca II | emission | 3p6.4s 2S → 3p6.4p 2P* | 实测值 | 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] | 实测值 | 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]* | 实测值 | 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] | 实测值 | 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] | 实测值 | 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] | 实测值 | 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] | 实测值 | 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] | 实测值 | 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] | 实测值 | 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]* | 实测值 | 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] | 实测值 | 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]* | 实测值 | 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]* | 实测值 | 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]* | 实测值 | 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]* | 实测值 | 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] | 实测值 | 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] | 实测值 | 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]* | 实测值 | NIST | |
| 501.9971 nm | 80 | Ca II | emission | 3p6.5p 2P* → 3p6.6d 2D | 实测值 | 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] | 实测值 | 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] | 实测值 | NIST |
扩展性质
共价半径（扩展）
- 共价半径（Pyykkö）
- 171 pm
- 共价半径（Pyykkö，双键）
- 147 pm
- 共价半径（Pyykkö，三键）
- 133 pm
- 共价半径（Bragg）
- 170 pm
范德华半径
- Truhlar
- 231 pm
- Batsanov
- 240 pm
- Alvarez
- 262 pm
- UFF
- 339.9 pm
- MM3
- 281 pm
原子半径与金属半径
- 原子半径（Rahm）
- 270 pm
- 金属半径（C12）
- 197 pm
编号标度
- Mendeleev
- 7
- Pettifor
- 16
- Glawe
- 16
电负性标度
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 3
- Robles–Bartolotti
- 2
极化率与色散
- 偶极极化率
- 160.8 a.u.
- 偶极极化率（不确定度）
- 4 a.u.
- C₆
- 2163 Ha·Bohr6
- C₆ (Gould–Bučko)
- 2230 Ha·Bohr6
Miedema参数
- Miedema摩尔体积
- 26.2 cm3/mol
- Miedema电子密度
- 1
供应风险与经济性
- 生产集中度
- 65
- 相对供应风险
- 6
- 政治稳定性（最大生产国）
- 24
相变与同素异形体
| 熔点 | 1115.15 K |
| 沸点 | 1757.15 K |
氧化态分类
高级参考数据
屏蔽常数 (6)
| n | 轨道 | 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 |
晶体半径详情 (6)
| 电荷 | CN | 自旋 | rcrystal (pm) | 来源 |
|---|---|---|---|---|
| 2 | VI | 114 | ||
| 2 | VII | 120 | ||
| 2 | VIII | 126 | ||
| 2 | IX | 132 | ||
| 2 | X | 137 | calculated, | |
| 2 | XII | 148 | calculated, |
同位素衰变方式 (50)
| 同位素 | 模式 | 强度 |
|---|---|---|
| 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射线散射因子 (504)
| 能量 (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 |
补充数据
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.