Calcium (Ca)
alkaline-earth-metalSolid
Peso atomico standard
40,078 uConfigurazione elettronica
[Ar] 4s2Punto di fusione
841,85 °CPunto di ebollizione
1483,85 °CDensità
1540 kg/m³Stati di ossidazione
+1, +2Elettronegatività (Pauling)
1Energia di ionizzazione (1ª)
6,113155 eVAnno della scoperta
1808Raggio atomico
180 pmDettagli
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.
Immagini
Proprietà
Fisiche
- Raggio atomico (empirico)
- 180 pm Confronta Raggio atomico (empirico) di tutti gli elementi →
- Raggio covalente
- 176 pm Confronta Raggio covalente di tutti gli elementi →
- Raggio di van der Waals
- 231 pm Confronta Raggio di van der Waals di tutti gli elementi →
- Raggio metallico
- 174 pm Confronta Raggio metallico di tutti gli elementi →
- Densità
- 1540 kg/m³ Confronta Densità di tutti gli elementi →
- Volume molare
- 0,0299 L/mol
- Fase in condizioni STP
- Solido Confronta Fase in condizioni STP di tutti gli elementi →
- Punto di fusione
- 841,85 °C Confronta Punto di fusione di tutti gli elementi →
- Punto di ebollizione
- 1483,85 °C Confronta Punto di ebollizione di tutti gli elementi →
- Capacità termica specifica
- 0,647 J/(g·K) Confronta Capacità termica specifica di tutti gli elementi →
- Capacità termica molare
- 25,929 J/(mol·K) Confronta Capacità termica molare di tutti gli elementi →
- Struttura cristallina
- Cubica a facce centrate Confronta Struttura cristallina di tutti gli elementi →
Chimiche
- Elettronegatività (Pauling)
- 1 Confronta Elettronegatività (Pauling) di tutti gli elementi →
- Elettronegatività (Allen)
- 1,034
- Affinità elettronica
- 0,0245 eV
- Energia di ionizzazione (1ª)
- 6,113155 eV Confronta Energia di ionizzazione (1ª) di tutti gli elementi →
- Energia di ionizzazione (2ª)
- 11,87176 eV Confronta Energia di ionizzazione (2ª) di tutti gli elementi →
- Energia di ionizzazione (3ª)
- 50,913335 eV Confronta Energia di ionizzazione (3ª) di tutti gli elementi →
- Energia di ionizzazione (4ª)
- 67,273432 eV Confronta Energia di ionizzazione (4ª) di tutti gli elementi →
- Energia di ionizzazione (5ª)
- 84,34029 eV Confronta Energia di ionizzazione (5ª) di tutti gli elementi →
- Stati di ossidazione
- +1, +2 Confronta Stati di ossidazione di tutti gli elementi →
- Elettroni di valenza
- 2 Confronta Elettroni di valenza di tutti gli elementi →
- Configurazione elettronica
- [Ar] 4s2
Termodinamiche
- Calore di fusione
- 0,08851117 eV Confronta Calore di fusione di tutti gli elementi →
- Calore di vaporizzazione
- 1,603358 eV Confronta Calore di vaporizzazione di tutti gli elementi →
- Calore di sublimazione
- 1,846919 eV
- Calore di atomizzazione
- 1,846919 eV
- Entalpia di atomizzazione
- 1,842773 eV
Nucleari
- Protoni
- 20 Confronta Protoni di tutti gli elementi →
- Neutroni
- 24 Confronta Neutroni di tutti gli elementi →
- Isotopi noti
- 29 Confronta Isotopi noti di tutti gli elementi →
- Isotopi stabili
- 4 Confronta Isotopi stabili di tutti gli elementi →
- Isotopo più stabile
- Ca-44
- Anno della scoperta
- 1808
Abbondanza
- Abbondanza (crosta terrestre)
- 4,15e+4 mg/kg Confronta Abbondanza (crosta terrestre) di tutti gli elementi →
- Abbondanza (oceano)
- 412 mg/L Confronta Abbondanza (oceano) di tutti gli elementi →
Struttura cristallina
- Costante reticolare a
- 558 pm
Struttura elettronica
- Elettroni per guscio
- 2, 8, 8, 2 Confronta Elettroni per guscio di tutti gli elementi →
Identificativi
- Numero CAS
- 7440-70-2 Confronta Numero CAS di tutti gli elementi →
- Simbolo di termine
- 1S0
- InChI
- InChI=1S/Ca
- Chiave InChI
- OYPRJOBELJOOCE-UHFFFAOYSA-N
Configurazione elettronica Misurato
Ca: 4s²[Ar] 4s²1s² 2s² 2p⁶ 3s² 3p⁶ 4s²Modello atomico
Gli isotopi modificano il numero di neutroni, la massa e la stabilità — non la configurazione elettronica di un atomo neutro.
Modello atomico schematico, non in scala.
Impronta atomica
Spettro di emissione / assorbimento
Distribuzione isotopica
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita |
|---|---|---|---|
| 42 Stabile | 41,95861783 ± 0,00000016 | 0,6470% | Stabile |
| 43 Stabile | 42,95876644 ± 0,00000024 | 0,1350% | Stabile |
| 44 Stabile | 43,95548156 ± 0,00000035 | 2,0860% | Stabile |
| 46 Stabile | 45,953689 ± 0,0000024 | 0,0040% | Stabile |
Fase / Stato
Motivo: 816,9 °C sotto il punto di fusione (841,85 °C)
Schema non in scala
Punti di transizione di fase
Energie di transizione
Energia necessaria per fondere 1 mol al punto di fusione
Energia necessaria per vaporizzare 1 mol al punto di ebollizione
Energia necessaria per sublimare 1 mol al punto di sublimazione
Densità
In condizioni standard
In condizioni standard
Spettri atomici
Sono visualizzati 10 di 20. Ordinamento per carica ionica crescente.
Righe disponibili ?
| Ione | Carica | Righe totali | Probabilità di transizione | Designazioni dei livelli |
|---|---|---|---|---|
| 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 |
Livelli disponibili ?
| Ione | Carica | Livelli |
|---|---|---|
| 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 |
Raggi ionici
| Carica | Coordinazione | Spin | Raggio |
|---|---|---|---|
| +2 | 6 | N/D | 100 pm |
| +2 | 7 | N/D | 106 pm |
| +2 | 8 | N/D | 112.00000000000001 pm |
| +2 | 9 | N/D | 118 pm |
| +2 | 10 | N/D | 123 pm |
| +2 | 12 | N/D | 134 pm |
Composti
Isotopi (4)
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita | Modalità di decadimento | |
|---|---|---|---|---|---|
| 42 Stabile | 41,95861783 ± 0,00000016 | 0,6470% ± 0,0230% | Stabile | stable | |
| 43 Stabile | 42,95876644 ± 0,00000024 | 0,1350% ± 0,0100% | Stabile | stable | |
| 44 Stabile | 43,95548156 ± 0,00000035 | 2,0860% ± 0,1100% | Stabile | stable | |
| 46 Stabile | 45,953689 ± 0,0000024 | 0,0040% ± 0,0030% | Stabile | stable |
Righe spettrali
Sono visualizzati 50 di 247. Per impostazione predefinita sono mostrate soltanto le righe spettrali con intensità misurata.
| Lunghezza d'onda (nm) | Intensità | Stadio di ionizzazione | Tipo | Transizione | Accuratezza | Fonte | |
|---|---|---|---|---|---|---|---|
| 408.1762 nm | 1000 | Ca III | emission | 3s2.3p5.4s 1P* → 3s2.3p5.4p 3S | Misurata | 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] | Misurata | 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] | Misurata | 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] | Misurata | 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] | Misurata | 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]* | Misurata | 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] | Misurata | 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] | Misurata | 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] | Misurata | 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]* | Misurata | 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] | Misurata | 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] | Misurata | 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] | Misurata | 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]* | Misurata | 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]* | Misurata | 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]* | Misurata | 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]* | Misurata | 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] | Misurata | 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]* | Misurata | 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] | Misurata | 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] | Misurata | 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]* | Misurata | 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]* | Misurata | 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] | Misurata | 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]* | Misurata | 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] | Misurata | 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]* | Misurata | NIST | |
| 393.3663 nm | 230 | Ca II | emission | 3p6.4s 2S → 3p6.4p 2P* | Misurata | 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] | Misurata | NIST | |
| 396.8469 nm | 220 | Ca II | emission | 3p6.4s 2S → 3p6.4p 2P* | Misurata | 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] | Misurata | 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]* | Misurata | 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] | Misurata | 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] | Misurata | 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] | Misurata | 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] | Misurata | 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] | Misurata | 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] | Misurata | 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]* | Misurata | 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] | Misurata | 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]* | Misurata | 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]* | Misurata | 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]* | Misurata | 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]* | Misurata | 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] | Misurata | 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] | Misurata | 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]* | Misurata | NIST | |
| 501.9971 nm | 80 | Ca II | emission | 3p6.5p 2P* → 3p6.6d 2D | Misurata | 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] | Misurata | 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] | Misurata | NIST |
Proprietà estese
Raggi covalenti (dati estesi)
- Raggio covalente (Pyykkö)
- 171 pm
- Raggio covalente (Pyykkö, legame doppio)
- 147 pm
- Raggio covalente (Pyykkö, legame triplo)
- 133 pm
- Raggio covalente (Bragg)
- 170 pm
Raggi di van der Waals
- Truhlar
- 231 pm
- Batsanov
- 240 pm
- Alvarez
- 262 pm
- UFF
- 339,9 pm
- MM3
- 281 pm
Raggi atomici e metallici
- Raggio atomico (Rahm)
- 270 pm
- Raggio metallico (C12)
- 197 pm
Scale di numerazione
- Mendeleev
- 7
- Pettifor
- 16
- Glawe
- 16
Scale di elettronegatività
- Ghosh
- 0
- Miedema
- 3
- Gunnarsson–Lundqvist
- 3
- Robles–Bartolotti
- 2
Polarizzabilità e dispersione
- Polarizzabilità dipolare
- 160,8 a.u.
- Polarizzabilità dipolare (inc.)
- 4 a.u.
- C₆
- 2163 Ha·Bohr6
- C₆ (Gould–Bučko)
- 2230 Ha·Bohr6
Parametri di Miedema
- Volume molare di Miedema
- 26,2 cm3/mol
- Densità elettronica di Miedema
- 1
Rischio di approvvigionamento ed economia
- Concentrazione della produzione
- 65
- Rischio relativo di approvvigionamento
- 6
- Stabilità politica (principale produttore)
- 24
Transizioni di fase e allotropi
| Punto di fusione | 1115,15 K |
| Punto di ebollizione | 1757,15 K |
Categorie degli stati di ossidazione
Dati di riferimento avanzati
Costanti di schermaggio (6)
| n | Orbitale | 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 |
Dettaglio dei raggi cristallini (6)
| Carica | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 2 | VI | 114 | ||
| 2 | VII | 120 | ||
| 2 | VIII | 126 | ||
| 2 | IX | 132 | ||
| 2 | X | 137 | calculated, | |
| 2 | XII | 148 | calculated, |
Modalità di decadimento degli isotopi (50)
| Isotopo | Modalità | Intensità |
|---|---|---|
| 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% |
Fattori di diffusione dei raggi X (504)
| Energia (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 |
Dati aggiuntivi
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
4.15×104 milligrams per kilogram
Riferimenti (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
4.12×102 milligrams per liter
Riferimenti (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.
Riferimenti (1)
- [6] Calcium https://periodic.lanl.gov/20.shtml
Riferimenti
(9)
Data deposited in or computed by PubChem
The half-life and atomic mass data was provided by the Atomic Mass Data Center at the International Atomic Energy Agency.
Element data are cited from the Atomic weights of the elements (an IUPAC Technical Report). The IUPAC periodic table of elements can be found at https://iupac.org/what-we-do/periodic-table-of-elements/. Additional information can be found within IUPAC publication doi:10.1515/pac-2015-0703 Copyright © 2020 International Union of Pure and Applied Chemistry.
The information are cited from Pure Appl. Chem. 2018; 90(12): 1833-2092, https://doi.org/10.1515/pac-2015-0703.
Thomas Jefferson National Accelerator Facility (Jefferson Lab) is one of 17 national laboratories funded by the U.S. Department of Energy. The lab's primary mission is to conduct basic research of the atom's nucleus using the lab's unique particle accelerator, known as the Continuous Electron Beam Accelerator Facility (CEBAF). For more information visit https://www.jlab.org/
The periodic table at the LANL (Los Alamos National Laboratory) contains basic element information together with the history, source, properties, use, handling and more. The provenance data may be found from the link under the source name.
The periodic table contains NIST's critically-evaluated data on atomic properties of the elements. The provenance data that include data for atomic spectroscopy, X-ray and gamma ray, radiation dosimetry, nuclear physics, and condensed matter physics may be found from the link under the source name. Ref: https://www.nist.gov/pml/atomic-spectra-database
This section provides all form of data related to element Calcium.
The element property data was retrieved from publications.