Strontium (Sr)
alkaline-earth-metalSolid
Peso atomico standard
87,62 uConfigurazione elettronica
[Kr] 5s2Punto di fusione
776,85 °CPunto di ebollizione
1381,85 °CDensità
2640 kg/m³Stati di ossidazione
+1, +2Elettronegatività (Pauling)
0,95Energia di ionizzazione (1ª)
5,694867 eVAnno della scoperta
1792Raggio atomico
200 pmDettagli
Strontium is an alkaline earth metal below calcium and above barium in group 2. Natural strontium is stable and occurs mainly as the minerals celestine and strontianite rather than as the free metal. Its chemistry is dominated by the Sr²⁺ ion, which closely resembles Ca²⁺ but is larger and more readily forms insoluble sulfate and carbonate salts. Strontium is best known technologically for red pyrotechnic colors, ferrite magnets, glass additives, and the radioactive isotope ⁹⁰Sr.
Strontium is softer than calcium and decomposes in water more vigorously. It does not absorb nitrogen below 380°C. It should be kept under kerosene to prevent oxidation. Freshly cut strontium has a silvery appearance, but rapidly turns a yellowish color with the formation of the oxide. The finely divided metal ignites spontaneously in air. Volatile strontium salts impart a beautiful crimson color to flames, and these salts are used in pyrotechnics and in the production of flares. Natural strontium is a mixture of four stable isotopes.
The name derives from Strontian, a town in Scotland. The mineral strontianite is found in mines in Strontian. The element was discovered in 1792 by the Scottish chemist and physician Thomas Charles Hope, who observed the brilliant red flame colour of strontium. It was first isolated by the English chemist Humphry Davy in 1808.
Strontium was discovered by Adair Crawford, an Irish chemist, in 1790 while studying the mineral witherite (BaCO3). When he mixed witherite with hydrochloric acid (HCl) he did not get the results he expected. He assumed that his sample of witherite was contaminated with an unknown mineral, a mineral he named strontianite (SrCO3). Strontium was first isolated by Sir Humphry Davy, an English chemist, in 1808 through the electrolysis of a mixture of strontium chloride (SrCl2) and mercuric oxide (HgO). Today, strontium is obtained from two of its most common ores, celestite (SrSO4) and strontianite (SrCO3), by treating them with hydrochloric acid, forming strontium chloride. The strontium chloride, usually mixed with potassium chloride (KCl), is then melted and electrolyzed, forming strontium and chlorine gas (Cl2).
Named after Strontian, a town in Scotland. Isolated by Davey by electrolysis in 1808, however, Adair Crawford recognized a new mineral (strontianite) as differing from other barium minerals in 1790.
Pure strontium is a soft, silvery metal when freshly cut, but it rapidly develops a yellowish or gray oxide-nitride surface film in air. It is less dense and less hard than many structural metals and is normally stored under oil or in sealed containers to limit reaction with moisture and oxygen.
Strontium nitrate, Sr(NO₃)₂, and related salts are used to produce intense red colors in fireworks, signal flares, and tracer compositions. Strontium carbonate, SrCO₃, is a feedstock for ceramic glazes, ferrite magnets, and specialty glass. Strontium ferrite materials are common permanent magnets in speakers, motors, and magnetic strips. ⁸⁷Sr/⁸⁶Sr ratios are used in geology, archaeology, and provenance studies. ⁹⁰Sr has been used in radioisotope power sources and industrial gauges, but its use is restricted by radiological hazards.
Most of the strontium produced today is used in the manufacture of color television picture tubes. It is also used to refine zinc and is combined with iron to make magnets.
Two strontium compounds, strontium carbonate (SrCO3) and strontium nitrate (Sr(NO3)2), burn with a bright, red flame and are used in fireworks and signal flares. Strontium carbonate is also used to make certain kinds of glass and is the base material for making most other strontium compounds.
Strontium-90, a radioactive isotope of strontium, is a common product of nuclear explosions. It has a half-life of about 28.8 years and decays into yttrium-90 through beta decay. Strontium-90 is especially deadly since it has a relatively long half-life, is strongly radioactive and is absorbed by the body, where it accumulates in the skeletal system. The radiation affects the production of new blood cells, which eventually leads to death.
In addition to the medical imaging application described in the image caption above, strontium has found use in producing ferrite magnets and in refining zinc. Strontium titanate is an interesting optical material as it has an extremely high refractive index and an optical dispersion greater than that of diamond. It has been used as a gemstone, but is very soft. It does not occur naturally.
Isotopes in Earth/Planetary Science
Stable isotopic fractionation of strontium is small because the relative differences between the masses of strontium stable isotopes are small (mass numbers are 86, 87, and 88 for the most abundant stable isotopes). Also, strontium is not subject to reduction-oxidation reactions in normal terrestrial environments, which would cause isotopic fractionation to be more evident. Nevertheless, current studies are exploring potential applications of stable strontium isotopic fractionation; for example, it has been used as a proxy for temperature during coral growth and for insights into the diets of ancient populations [295] A. Rüggeberg, J. Fietzke, V. Liebetrau, A. Eisenhauer, W. C. Dullo, A. Freiwald. Earth Planet. Sci. Lett.269, 570 (2008)., [296] K. J. Knudson, H. M. Williams, J. E. Buikstra, P. D. Tomczak, G. W. Gordon, A. D. Anbar. J. Archaeolog. Sci.37, 2352 (2010)..
The relative abundance of natural radiogenic 87Sr in seawater is related to the relative rates of processes that add or remove strontium in the ocean (seafloor spreading, mid-ocean-ridge hydrothermal activity, and continental weathering). Over geologic time, these processes have fluctuated and the isotope-amount ratio n(87Sr)/n(86Sr) has changed systematically. By measuring the n(87Sr)/n(86Sr) ratio in marine fossils of known age, it is possible to identify when such environmental changes occurred. Conversely, it is possible to estimate the ages of marine deposits by comparing measured n(87Sr)/n(86Sr) ratios with the global time chart; this process is known as strontium isotope stratigraphy [297] J. M. McArthur, R. J. Howarth, T. R. Bailey. J. Geol.109, 155 (2001)..
Isotopes in Forensic Science and Anthropology
The isotope-amount ratio n(87Sr)/n(86Sr) is highly variable in rocks, minerals, soils, and waters, and it can be transmitted to plants (Fig. IUPAC.38.1), animals, and manufactured materials. Measurements of n(87Sr)/n(86Sr) ratios are used for forensic applications in food authentication (determining where food came from), archaeology, crime-scene investigation, and human migration [298] B. L. Beard, C. M. Johnson. J. Forensic Sci.45, 1049 (2000)., [299] K. M. Frei, R. Frei. Appl. Geochem.26, 326 (2011)..
Isotopes in Geochronology
The 87Rb- 87Sr dating technique utilizes the fact that 87Sr is a product of radioactive 87Rb decay (half-life of 4.97×1010 years) and is a useful tool for determining ages of rocks and minerals spanning the age of the Earth (Fig. IUPAC.38.2) [301] G. Faure. Principles of Isotope Geology, 2nd Edition. p. 608. Wiley, New York (1986)..
Strontium almost always forms compounds in the +2 oxidation state. Strontium oxide, SrO, is a strongly basic oxide that reacts with water to form strontium hydroxide, Sr(OH)₂. Strontium carbonate, SrCO₃, and strontium sulfate, SrSO₄, are sparingly soluble and control much of its mineral behavior. Strontium chloride, SrCl₂, and strontium nitrate, Sr(NO₃)₂, are soluble salts used as chemical intermediates. Strontium titanate, SrTiO₃, is a high-refractive-index ceramic and an important substrate material in oxide electronics research.
Strontium is found chiefly as celestite and strontianite. The metal can be prepared by electrolysis of the fused chloride mixed with potassium chloride, or is made by reducing strontium oxide with aluminum in a vacuum at a temperature at which strontium distills off. Three allotropic forms of the metal exist, with transition points at 235 and 540°C.
See more information at the Strontium compound page.
Metallic strontium reacts with water and acids to release hydrogen, H₂, and can ignite as filings or powder. Soluble strontium salts have moderate chemical toxicity and can disturb calcium metabolism at high exposure. The main radiological concern is ⁹⁰Sr, a fission product that behaves partly like calcium in the body and irradiates bone and marrow through beta decay. Stable strontium in ordinary environmental concentrations is not highly hazardous.
Strontium is dispersed in rocks, soils, freshwater, and seawater, with higher mobility in soluble forms than barium but less than many alkali metals. It substitutes for calcium in minerals and biological hard tissues because Sr²⁺ and Ca²⁺ have similar charge and chemistry. Weathering releases strontium to waters, while carbonate, sulfate, and adsorption processes remove it. ⁹⁰Sr from nuclear fallout or accidents is environmentally important because it can enter food chains.
Commercial strontium is obtained chiefly from celestine, SrSO₄, which is converted to strontium carbonate, SrCO₃, or other salts before further use. Demand is concentrated in ferrite magnets, pyrotechnics, ceramics, and specialty glass, so the market is smaller and less diversified than for calcium or magnesium. Production of the metal itself is limited because most applications use compounds. Recycling is modest and usually indirect, for example through recovery or reuse of magnet-containing products rather than elemental strontium recovery.
Found in minerals celestite and strontianite.
Strontium is a trace element in the cosmos, produced mainly by neutron-capture processes in evolved stars and explosive stellar events. It is much less abundant than lighter rock-forming elements but is detectable in stellar spectra. In the solar system it follows calcium and other lithophile elements into silicate minerals, while only minute amounts occur in metallic phases or volatile reservoirs.
- The element is named after Strontian, a village in Scotland where strontianite was identified.
- Strontium salts give a cleaner crimson flame than many mixtures based on lithium or calcium.
- Strontium titanate was once used as a diamond simulant before harder simulants became common.
- Natural ⁸⁷Sr partly derives from the decay of ⁸⁷Rb, making Sr isotope ratios useful as geological clocks.
- Celestine is named for its pale blue color, although strontium compounds themselves are often white.
Immagini
Proprietà
Fisiche
- Raggio atomico (empirico)
- 200 pm Confronta Raggio atomico (empirico) di tutti gli elementi →
- Raggio covalente
- 195 pm Confronta Raggio covalente di tutti gli elementi →
- Raggio di van der Waals
- 249 pm Confronta Raggio di van der Waals di tutti gli elementi →
- Raggio metallico
- 191 pm Confronta Raggio metallico di tutti gli elementi →
- Densità
- 2640 kg/m³ Confronta Densità di tutti gli elementi →
- Volume molare
- 0,0337 L/mol
- Fase in condizioni STP
- Solido Confronta Fase in condizioni STP di tutti gli elementi →
- Punto di fusione
- 776,85 °C Confronta Punto di fusione di tutti gli elementi →
- Punto di ebollizione
- 1381,85 °C Confronta Punto di ebollizione di tutti gli elementi →
- Capacità termica specifica
- 0,306 J/(g·K) Confronta Capacità termica specifica di tutti gli elementi →
- Capacità termica molare
- 26,79 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)
- 0,95 Confronta Elettronegatività (Pauling) di tutti gli elementi →
- Elettronegatività (Allen)
- 0,963
- Affinità elettronica
- 0,052 eV
- Energia di ionizzazione (1ª)
- 5,694867 eV Confronta Energia di ionizzazione (1ª) di tutti gli elementi →
- Energia di ionizzazione (2ª)
- 11,030314 eV Confronta Energia di ionizzazione (2ª) di tutti gli elementi →
- Energia di ionizzazione (3ª)
- 42,883678 eV Confronta Energia di ionizzazione (3ª) di tutti gli elementi →
- Energia di ionizzazione (4ª)
- 56,280194 eV Confronta Energia di ionizzazione (4ª) di tutti gli elementi →
- Energia di ionizzazione (5ª)
- 70,700243 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
- [Kr] 5s2
Termodinamiche
- Calore di fusione
- 0,08602373 eV Confronta Calore di fusione di tutti gli elementi →
- Calore di vaporizzazione
- 1,421983 eV Confronta Calore di vaporizzazione di tutti gli elementi →
- Calore di sublimazione
- 1,703892 eV
- Calore di atomizzazione
- 1,703892 eV
- Entalpia di atomizzazione
- 1,699746 eV
Nucleari
- Protoni
- 38 Confronta Protoni di tutti gli elementi →
- Neutroni
- 50 Confronta Neutroni di tutti gli elementi →
- Isotopi noti
- 35 Confronta Isotopi noti di tutti gli elementi →
- Isotopi stabili
- 4 Confronta Isotopi stabili di tutti gli elementi →
- Isotopo più stabile
- Sr-88
- Anno della scoperta
- 1792
Abbondanza
- Abbondanza (crosta terrestre)
- 370 mg/kg Confronta Abbondanza (crosta terrestre) di tutti gli elementi →
- Abbondanza (oceano)
- 7,9 mg/L Confronta Abbondanza (oceano) di tutti gli elementi →
Struttura cristallina
- Costante reticolare a
- 608 pm
Struttura elettronica
- Elettroni per guscio
- 2, 8, 18, 8, 2 Confronta Elettroni per guscio di tutti gli elementi →
Identificativi
- Numero CAS
- 7440-24-6 Confronta Numero CAS di tutti gli elementi →
- Simbolo di termine
- 1S0
- InChI
- InChI=1S/Sr
- Chiave InChI
- CIOAGBVUUVVLOB-UHFFFAOYSA-N
Configurazione elettronica Misurato
Sr: 5s²[Kr] 5s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 5s²Modello 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 |
|---|---|---|---|
| 84 Stabile | 83,9134191 ± 0,0000013 | 0,5600% | Stabile |
| 86 Stabile | 85,9092606 ± 0,0000012 | 9,8600% | Stabile |
| 87 Stabile | 86,9088775 ± 0,0000012 | 7,0000% | Stabile |
| 88 Stabile | 87,9056125 ± 0,0000012 | 82,5800% | Stabile |
Fase / Stato
Motivo: 751,9 °C sotto il punto di fusione (776,85 °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 38. Ordinamento per carica ionica crescente.
Righe disponibili ?
| Ione | Carica | Righe totali | Probabilità di transizione | Designazioni dei livelli |
|---|---|---|---|---|
| Sr I | 0 | 361 | 86 | 361 |
| Sr II | +1 | 135 | 33 | 135 |
| Sr III | +2 | 613 | 0 | 613 |
| Sr IV | +3 | 1183 | 0 | 1183 |
| Sr V | +4 | 625 | 0 | 625 |
| Sr VI | +5 | 57 | 14 | 57 |
| Sr VII | +6 | 30 | 30 | 30 |
| Sr VIII | +7 | 26 | 24 | 26 |
| Sr IX | +8 | 46 | 28 | 46 |
| Sr X | +9 | 54 | 51 | 54 |
Livelli disponibili ?
| Ione | Carica | Livelli |
|---|---|---|
| Sr I | 0 | 380 |
| Sr II | +1 | 72 |
| Sr III | +2 | 150 |
| Sr IV | +3 | 255 |
| Sr V | +4 | 144 |
| Sr VI | +5 | 22 |
| Sr VII | +6 | 20 |
| Sr VIII | +7 | 21 |
| Sr IX | +8 | 31 |
| Sr X | +9 | 47 |
Raggi ionici
| Carica | Coordinazione | Spin | Raggio |
|---|---|---|---|
| +2 | 6 | N/D | 118 pm |
| +2 | 7 | N/D | 121 pm |
| +2 | 8 | N/D | 126 pm |
| +2 | 9 | N/D | 131 pm |
| +2 | 10 | N/D | 136 pm |
| +2 | 12 | N/D | 144 pm |
Composti
Isotopi (4)
Sixteen other unstable isotopes are known to exist. Of greatest importance is 90Sr with a half-life of 29 years. It is a product of nuclear fallout and presents a health problem. This isotope is one of the best long-lived high-energy beta emitters known, and is used in SNAP (Systems for Nuclear Auxilliary Power) devices. These devices hold promise for use in space vehicles, remote weather stations, navigational buoys, etc., and where a lightweight, long-lived, nuclear-electric power source is needed.
| Numero di massa | Massa atomica (u) | Abbondanza naturale | Emivita | Modalità di decadimento | |
|---|---|---|---|---|---|
| 84 Stabile | 83,9134191 ± 0,0000013 | 0,5600% ± 0,0100% | Stabile | stable | |
| 86 Stabile | 85,9092606 ± 0,0000012 | 9,8600% ± 0,0100% | Stabile | stable | |
| 87 Stabile | 86,9088775 ± 0,0000012 | 7,0000% ± 0,0100% | Stabile | stable | |
| 88 Stabile | 87,9056125 ± 0,0000012 | 82,5800% ± 0,0100% | Stabile | stable |
Righe spettrali
Sono visualizzati 50 di 500. Per impostazione predefinita sono mostrate soltanto le righe spettrali con intensità misurata.
| Lunghezza d'onda (nm) | Intensità | Stadio di ionizzazione | Tipo | Transizione | Accuratezza | Fonte | |
|---|---|---|---|---|---|---|---|
| 707.0072 nm | 14000 | Sr I | emission | 5s.5p 3P* → 5s.6s 3S | Misurata | NIST | |
| 687.83128 nm | 12000 | Sr I | emission | 5s.5p 3P* → 5s.6s 3S | Misurata | NIST | |
| 679.10198 nm | 7000 | Sr I | emission | 5s.5p 3P* → 5s.6s 3S | Misurata | NIST | |
| 525.68986 nm | 3400 | Sr I | emission | 5s.4d 3D → 4d.5p 3P* | Misurata | NIST | |
| 640.8463 nm | 3100 | Sr I | emission | 5s.4d 3D → 4d.5p 3F* | Misurata | NIST | |
| 483.20425 nm | 2900 | Sr I | emission | 5s.5p 3P* → 5s.5d 3D | Misurata | NIST | |
| 548.08638 nm | 2700 | Sr I | emission | 5s.4d 3D → 4d.5p 3D* | Misurata | NIST | |
| 496.2263 nm | 2500 | Sr I | emission | 5s.5p 3P* → 5s.5d 3D | Misurata | NIST | |
| 481.18799 nm | 2300 | Sr I | emission | 5s.5p 3P* → 5p2 3P | Misurata | NIST | |
| 689.25894 nm | 2300 | Sr I | emission | 5s2 1S → 5s.5p 3P* | Misurata | NIST | |
| 650.3992 nm | 2100 | Sr I | emission | 5s.4d 3D → 4d.5p 3F* | Misurata | NIST | |
| 523.85479 nm | 2000 | Sr I | emission | 5s.4d 3D → 4d.5p 3P* | Misurata | NIST | |
| 550.4181 nm | 2000 | Sr I | emission | 5s.4d 3D → 4d.5p 3D* | Misurata | NIST | |
| 496.5585 nm | 1900 | Sr I | emission | 5s.5p 1P* → 5s.7d 1D | Misurata | NIST | |
| 516.5486 nm | 1800 | Sr I | emission | 5s.5p 1P* → 5s.8s 1S | Misurata | NIST | |
| 478.43198 nm | 1700 | Sr I | emission | 5s.5p 3P* → 5p2 3P | Misurata | NIST | |
| 552.1768 nm | 1700 | Sr I | emission | 5s.4d 3D → 4d.5p 3D* | Misurata | NIST | |
| 730.94166 nm | 1700 | Sr I | emission | 5s.4d 1D → 4d.5p 1D* | Misurata | NIST | |
| 472.22769 nm | 1600 | Sr I | emission | 5s.5p 3P* → 5p2 3P | Misurata | NIST | |
| 474.19221 nm | 1600 | Sr I | emission | 5s.5p 3P* → 5p2 3P | Misurata | NIST | |
| 478.3782 nm | 1500 | Sr I | emission | 5s.5p 1P* → 5s.9s 1S | Misurata | NIST | |
| 487.249 nm | 1500 | Sr I | emission | 5s.5p 3P* → 5s.5d 3D | Misurata | NIST | |
| 489.198 nm | 1500 | Sr I | emission | 5s.4d 3D → 5s.4f 3F* | Misurata | NIST | |
| 581.67702 nm | 1500 | Sr I | emission | 5s.4d 1D → 4d.5p 3P* | Misurata | NIST | |
| 468.8546 nm | 1400 | Sr I | emission | 5s.5p 1P* → 5s.8d 1D | Misurata | NIST | |
| 522.21992 nm | 1400 | Sr I | emission | 5s.4d 3D → 4d.5p 3P* | Misurata | NIST | |
| 522.51079 nm | 1400 | Sr I | emission | 5s.4d 3D → 4d.5p 3P* | Misurata | NIST | |
| 522.92697 nm | 1400 | Sr I | emission | 5s.4d 3D → 4d.5p 3P* | Misurata | NIST | |
| 555.6375 nm | 1400 | Sr I | emission | 5s.5p 1P* → 5s.6d 3D | Misurata | NIST | |
| 634.57265 nm | 1400 | Sr I | emission | 5s.4d 3D → 5s.6p 3P* | Misurata | NIST | |
| 655.0244 nm | 1400 | Sr I | emission | 5s.5p 1P* → 4d2 1D | Misurata | NIST | |
| 495.6274 nm | 1300 | Sr I | emission | 5s.5p 1P* → 5s.7d 3D | Misurata | NIST | |
| 638.64581 nm | 1300 | Sr I | emission | 5s.4d 3D → 5s.6p 3P* | Misurata | NIST | |
| 485.50448 nm | 1200 | Sr I | emission | 5s.4d 3D → 5s.4f 3F* | Misurata | NIST | |
| 486.87005 nm | 1200 | Sr I | emission | 5s.4d 3D → 5s.4f 3F* | Misurata | NIST | |
| 487.60745 nm | 1200 | Sr I | emission | 5s.5p 3P* → 5s.5d 3D | Misurata | NIST | |
| 496.7942 nm | 1200 | Sr I | emission | 5s.5p 3P* → 5s.5d 3D | Misurata | NIST | |
| 559.8159 nm | 1200 | Sr I | emission | 5s.4d 1D → 4d.5p 1F* | Misurata | NIST | |
| 458.29879 nm | 1100 | Sr I | emission | 5s.5p 1P* → 5s.10s 1S | Misurata | NIST | |
| 486.91724 nm | 1100 | Sr I | emission | 5s.4d 3D → 5s.4f 3F* | Misurata | NIST | |
| 489.2642 nm | 1100 | Sr I | emission | 5s.4d 3D → 5s.4f 3F* | Misurata | NIST | |
| 661.72651 nm | 1100 | Sr I | emission | 5s.4d 3D → 4d.5p 3F* | Misurata | NIST | |
| 403.03772 nm | 1000 | Sr I | emission | 5s.5p 3P* → 5s.6d 3D | Misurata | NIST | |
| 443.8043 nm | 1000 | Sr I | emission | 5s.5p 3P* → 5s.7s 3S | Misurata | NIST | |
| 446.32981 nm | 1000 | Sr I | emission | 5s.5p 1P* → 5s.11s 1S | Misurata | NIST | |
| 453.2375 nm | 1000 | Sr I | emission | 5s.5p 1P* → 5s.9d 1D | Misurata | NIST | |
| 471.2151 nm | 1000 | Sr I | emission | 5s.4d 1D → 5s.5f 3F* | Misurata | NIST | |
| 545.08373 nm | 1000 | Sr I | emission | 5s.4d 3D → 4d.5p 3D* | Misurata | NIST | |
| 548.6135 nm | 1000 | Sr I | emission | 5s.4d 3D → 4d.5p 3D* | Misurata | NIST | |
| 553.4799 nm | 1000 | Sr I | emission | 5s.4d 3D → 4d.5p 3D* | Misurata | NIST |
Proprietà estese
Raggi covalenti (dati estesi)
- Raggio covalente (Pyykkö)
- 185 pm
- Raggio covalente (Pyykkö, legame doppio)
- 157 pm
- Raggio covalente (Pyykkö, legame triplo)
- 139 pm
- Raggio covalente (Bragg)
- 195 pm
Raggi di van der Waals
- Truhlar
- 249 pm
- Batsanov
- 255 pm
- Alvarez
- 284 pm
- UFF
- 364,1 pm
- MM3
- 300 pm
Raggi atomici e metallici
- Raggio atomico (Rahm)
- 279 pm
- Raggio metallico (C12)
- 215 pm
Scale di numerazione
- Mendeleev
- 8
- Pettifor
- 15
- Glawe
- 15
Scale di elettronegatività
- Ghosh
- 0
- Miedema
- 2
- Gunnarsson–Lundqvist
- 3
- Robles–Bartolotti
- 2
Polarizzabilità e dispersione
- Polarizzabilità dipolare
- 197,2 a.u.
- Polarizzabilità dipolare (inc.)
- 0,2 a.u.
- C₆
- 3175 Ha·Bohr6
- C₆ (Gould–Bučko)
- 3230 Ha·Bohr6
Parametri di Miedema
- Volume molare di Miedema
- 33,93 cm3/mol
- Densità elettronica di Miedema
- 1
Rischio di approvvigionamento ed economia
- Concentrazione della produzione
- 83
- Rischio relativo di approvvigionamento
- 9
- Distribuzione delle riserve
- 100
- Stabilità politica (principale produttore)
- 24
- Stabilità politica (principale detentore di riserve)
- 24
Transizioni di fase e allotropi
| Punto di fusione | 1050,15 K |
| Punto di ebollizione | 1650,15 K |
Categorie degli stati di ossidazione
Dati di riferimento avanzati
Costanti di schermaggio (9)
| n | Orbitale | σ |
|---|---|---|
| 1 | s | 0,8089 |
| 2 | p | 3,9696 |
| 2 | s | 10,0982 |
| 3 | d | 15,2738 |
| 3 | p | 15,8324 |
| 3 | s | 15,3362 |
| 4 | p | 26,068 |
| 4 | s | 24,5556 |
| 5 | s | 31,9295 |
Dettaglio dei raggi cristallini (6)
| Carica | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 2 | VI | 132 | ||
| 2 | VII | 135 | ||
| 2 | VIII | 140 | ||
| 2 | IX | 145 | ||
| 2 | X | 150 | calculated, | |
| 2 | XII | 158 | calculated, |
Modalità di decadimento degli isotopi (54)
| Isotopo | Modalità | Intensità |
|---|---|---|
| 73 | B+ | 100% |
| 73 | B+p | 63% |
| 74 | B+ | 100% |
| 74 | B+p | — |
| 75 | B+ | 100% |
| 75 | B+p | 5,2% |
| 76 | B+ | 100% |
| 76 | B+p | 3,4% |
| 77 | B+ | 100% |
| 77 | B+p | 0,1% |
Fattori di diffusione dei raggi X (508)
| Energia (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0,17126 |
| 10,1617 | — | 0,1749 |
| 10,3261 | — | 0,17861 |
| 10,4931 | — | 0,1824 |
| 10,6628 | — | 0,18627 |
| 10,8353 | — | 0,19061 |
| 11,0106 | — | 0,19514 |
| 11,1886 | — | 0,19977 |
| 11,3696 | — | 0,2045 |
| 11,5535 | — | 0,20936 |
Dati aggiuntivi
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
3.70×102 milligrams per kilogram
Riferimenti (1)
- [5] Strontium https://education.jlab.org/itselemental/ele038.html
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
7.9 milligrams per liter
Riferimenti (1)
- [5] Strontium https://education.jlab.org/itselemental/ele038.html
Isotopes in Forensic Science and Anthropology
Information on the use of this element's isotopes in forensic science and anthropology.
The isotope-amount ratio n(87Sr)/n(86Sr) is highly variable in rocks, minerals, soils, and waters, and it can be transmitted to plants (Fig. IUPAC.38.1), animals, and manufactured materials. Measurements of n(87Sr)/n(86Sr) ratios are used for forensic applications in food authentication (determining where food came from), archaeology, crime-scene investigation, and human migration [298] B. L. Beard, C. M. Johnson. J. Forensic Sci.45, 1049 (2000)., [299] K. M. Frei, R. Frei. Appl. Geochem.26, 326 (2011)..
Riferimenti (4)
- [298] B. L. Beard, C. M. Johnson. J. Forensic Sci.45, 1049 (2000).
- [299] K. M. Frei, R. Frei. Appl. Geochem.26, 326 (2011).
- [300] K. Miller, T. B. Coplen, M. Wieser. “Identification of the geographical origin of exotic wood species using 87Sr/86Sr isotope amount ratios”, in Goldschmidt 22nd Conference, Montreal, Quebec, Canada.
- [4] IUPAC Periodic Table of the Elements and Isotopes (IPTEI) https://doi.org/10.1515/pac-2015-0703
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 Strontium.
The element property data was retrieved from publications.