Barium (Ba)
alkaline-earth-metalSolid
Masse atomique relative standard
137,327 uConfiguration électronique
[Xe] 6s2Point de fusion
726,85 °CPoint d’ébullition
1896,85 °CMasse volumique
3620 kg/m³États d’oxydation
+1, +2Électronégativité (Pauling)
0,89Énergie d’ionisation (1re)
5,211665 eVAnnée de découverte
1808Rayon atomique
215 pmDétails
Barium is a soft alkaline earth metal, below strontium and above radium in group 2. It is highly reactive, forms Ba²⁺ compounds almost exclusively, and is not found free in nature. Its most important minerals are barite, barium sulfate, and witherite, barium carbonate. The element is technologically significant less as a metal than through dense, insoluble, or optically useful compounds.
Barium is a metallic element, soft, and when pure is silvery white; it belongs to the alkaline earth group, chemically resembling calcium. The metal oxidizes very easily and should be kept under petroleum or other suitable oxygen-free liquids to exclude air. It is decomposed by water or alcohol.
Barium was first isolated by Sir Humphry Davy, an English chemist, in 1808 through the electrolysis of molten baryta (BaO). Barium is never found free in nature since it reacts with oxygen in the air, forming barium oxide (BaO), and with water, forming barium hydroxide (Ba(OH)2) and hydrogen gas (H2). Barium is most commonly found as the mineral barite (BaSO4) and witherite (BaCO3) and is primarily produced through the electrolysis of barium chloride (BaCl2).
From the Greek word barys, heavy. Baryta was distinguished from lime by Scheele in 1774; the element was discovered by Sir Humphrey Davy in 1808.
Pure barium is a silvery-white to pale yellow metal when freshly cut. It tarnishes rapidly in air as oxide, nitride, and peroxide-containing surface films form. The metal is soft, relatively dense for an alkaline earth metal, and is normally stored under oil or inert gas.
Elemental barium has limited direct use because of its reactivity. It has been used as a getter in vacuum tubes, where it removes residual gases by forming stable compounds. Barium compounds have broader roles: barium sulfate (BaSO₄) is used as a radiopaque contrast material and as an inert filler; barium titanate (BaTiO₃) is a ferroelectric ceramic used in capacitors and related devices; and barium nitrate (Ba(NO₃)₂) and barium chlorate (Ba(ClO₃)₂) can produce green colors in pyrotechnics.
Barium is used as a getter, a material that combines with and removes trace gases from vacuum tubes.
Barium sulfate (BaSO4), a common barium compound, is used as a filler for rubber, plastics and resins. It can be combined with zinc oxide (ZnO) to make a white pigment known as lithophone or with sodium sulfate (Na2SO4) to make another white pigment known as blanc fixe. Stones made from impure barium sulfate glow when exposed to light and will glow in the dark for up to six years if intensely heated in the presence of charcoal. These stones, known as Bologna stones, were discovered near Bologna, Italy in the early 1500s and were thought to possess magical properties by alchemists. Although all barium compounds are poisonous, barium sulfate can be safely ingested since it does not dissolve in water. It is also a good absorber of X-rays and, when swallowed, can be used to produce X-ray images of the intestinal tract.
Barium carbonate (BaCO3), another common barium compound, is used in the manufacture of ceramics and some types of glass. It is a component in clay slurries used in drilling oil wells. Barium carbonate is used to purify some chemical solutions and is the primary base material for the manufacture of other barium compounds.
Barium forms several other useful compounds. Barium nitrate (Ba(NO3)2) burns with a bright green color and is used in signal flares and fireworks. Barium chloride (BaCl) is used as a water softener. Barium oxide (BaO) easily absorbs moisture and is used as a desiccant. Barium peroxide (BaO2) forms hydrogen peroxide (H2O2) when it is mixed with water and is used as a bleaching agent that activates when wet. Barium titanate (BaTiO3) is used as a dielectric material in capacitors. Barium ferrite (BaO·6Fe2O3) is used to make magnets.
Barium-137m, a radioactive form of barium produced by the decay of cesium-137, has a relatively short half-life and is commonly used in high school and college physics half-life determination experiments.
The metal is used as a "getter" in vacuum tubes. The most important compounds are the peroxide, chloride, sulfate, carbonate, nitrate, and chlorate. Lithopone, a pigment containing barium sulfate and zinc sulfide, has good covering power, and does not darken in the presence of sulfides. The sulfate, as permanent white is also used in paint, in X-ray diagnostic work, and in glassmaking. Barite is extensively used as a weighing agent in oil well drilling fluids, and is used in making rubber. The carbonate has been used as a rat poison, while the nitrate and chlorate give colors in pyrotechnics. The impure sulfide phosphoresces after exposure to the light. All barium compounds that are water or acid soluble are poisonous. Naturally occurring barium is a mixture of seven stable isotopes. Twenty two other radioactive isotopes are known to exist.
Isotopes in Earth/Planetary Science
Because molecules, atoms, and ions of the stable isotopes of barium possess slightly different physical and chemical properties, they can be fractionated during physical, chemical, and biological processes, giving rise to variations in isotopic abundances and in atomic weights. von Allmen et al. [410] K. v. Allmen, M. E. Böttcher, E. Samankassou, T. F. Nägler. Chem. Geol.277, 70 (2010). observed barium isotopic fractionation in the global barium cycle (Fig. IUPAC.56.1).
High-precision barium isotope measurements reveal differences of up to 25 parts per million in the isotope-amount ratio n(137Ba)/n(136Ba) and 60 parts per million in the n(138Ba)/n(136Ba) ratio between chondrites and the Earth. These differences probably arose from incomplete mixing of nucleosynthetic material in the solar nebula. Barium isotopes may be the decay products of now-extinct 135Cs (with a half-life of about 1.6×106 years), which is thought to be a nucleosynthetic component. Chondritic meteorites have a slight excess of supernova-derived material as compared to Earth, demonstrating that the solar nebula was not perfectly homogenized upon formation (Fig. IUPAC.56.1) [411] M. C. Ranen, S. B. Jacobsen. Science314, 809 (2006)., [412] H. Hidaka, Y. Ohta, S. Yoneda. Earth. Planet. Sci. Lett.214, 455 (2003)., [413] S. B. Jacobsen, M. C. Ranen. Geochim. Cosmochim. Acta70, A286 (2006)..
Barium chemistry is dominated by the +2 oxidation state and by large, mostly ionic Ba²⁺ salts. Barium oxide (BaO) is a basic oxide, while barium hydroxide (Ba(OH)₂) is a strong base. Barium sulfate (BaSO₄) is exceptionally insoluble, a property central to analytical sulfate tests and medical contrast use. Barium carbonate (BaCO₃), barium chloride (BaCl₂), and barium nitrate (Ba(NO₃)₂) are important laboratory or industrial salts, but soluble barium salts are toxic. Mixed oxides such as barium titanate (BaTiO₃) are important functional ceramics.
See more information at the Barium compound page.
Metallic barium reacts with moisture and can ignite or release hydrogen, so it is handled as an air-sensitive reactive metal. Soluble barium compounds, including barium chloride (BaCl₂) and barium nitrate (Ba(NO₃)₂), are poisonous because Ba²⁺ interferes with potassium ion transport and muscle function. Barium sulfate (BaSO₄) is far less hazardous by ingestion because of its very low solubility, provided it is free of soluble barium impurities.
Barium occurs naturally in crustal rocks, especially as barite, barium sulfate (BaSO₄), and witherite, barium carbonate (BaCO₃). Its mobility depends strongly on sulfate, carbonate, and pH conditions; insoluble sulfate tends to immobilize it, while soluble salts can enter groundwater locally. Barium is not an essential nutrient for most organisms, and elevated soluble barium can be harmful to aquatic and terrestrial life.
Barium is supplied mainly through mining and processing of barite, barium sulfate (BaSO₄), with smaller contributions from other barium minerals where available. Much barite is consumed directly after grinding, especially where high density and chemical inertness are useful, rather than being converted to metal. Barium metal is made by reducing barium compounds under controlled conditions and is a small specialty product. Demand is driven by drilling fluids, fillers, ceramics, glass, pyrotechnics, and chemical manufacture; substitution is possible in some uses but difficult where density, insolubility, or specific electronic properties are required.
It is found only in combination with other elements, chiefly with sulfate and carbonate and is prepared by electrolysis of the chloride.
Barium is heavier than iron and is formed mainly by neutron-capture processes in stars, especially the slow s-process in evolved stars and the rapid r-process in explosive or merger environments. Its spectral lines are important in stellar abundance studies, and barium enrichment in some stars records past nucleosynthesis and mass transfer. In planetary materials it is a trace lithophile element concentrated in minerals and melts rather than metallic cores.
- Barium sulfate is so insoluble that it can be swallowed for X-ray imaging despite barium ion toxicity.
- The name comes from Greek barys, meaning heavy, reflecting the high density of barite.
- Barium flame tests give an apple-green color, though impurities can mask it.
- Natural barium is a mixture of several stable isotopes, with ¹³⁸Ba the most abundant.
- Barium titanate was one of the first widely important ferroelectric ceramics.
Images
Propriétés
Propriétés physiques
- Rayon atomique (empirique)
- 215 pm Comparer : Rayon atomique (empirique) de tous les éléments →
- Rayon covalent
- 215 pm Comparer : Rayon covalent de tous les éléments →
- Rayon de van der Waals
- 268 pm Comparer : Rayon de van der Waals de tous les éléments →
- Rayon métallique
- 198 pm Comparer : Rayon métallique de tous les éléments →
- Masse volumique
- 3620 kg/m³ Comparer : Masse volumique de tous les éléments →
- Volume molaire
- 0,039 L/mol
- Phase aux CNTP
- Solide Comparer : Phase aux CNTP de tous les éléments →
- Point de fusion
- 726,85 °C Comparer : Point de fusion de tous les éléments →
- Point d’ébullition
- 1896,85 °C Comparer : Point d’ébullition de tous les éléments →
- Capacité thermique massique
- 0,204 J/(g·K) Comparer : Capacité thermique massique de tous les éléments →
- Capacité thermique molaire
- 28,07 J/(mol·K) Comparer : Capacité thermique molaire de tous les éléments →
- Structure cristalline
- Cubique centré Comparer : Structure cristalline de tous les éléments →
Propriétés chimiques
- Électronégativité (Pauling)
- 0,89 Comparer : Électronégativité (Pauling) de tous les éléments →
- Électronégativité (Allen)
- 0,881
- Affinité électronique
- 0,1447 eV
- Énergie d’ionisation (1re)
- 5,211665 eV Comparer : Énergie d’ionisation (1re) de tous les éléments →
- Énergie d’ionisation (2e)
- 10,00386 eV Comparer : Énergie d’ionisation (2e) de tous les éléments →
- Énergie d’ionisation (3e)
- 35,843923 eV Comparer : Énergie d’ionisation (3e) de tous les éléments →
- Énergie d’ionisation (4e)
- 47,000162 eV Comparer : Énergie d’ionisation (4e) de tous les éléments →
- Énergie d’ionisation (5e)
- 58,0002 eV Comparer : Énergie d’ionisation (5e) de tous les éléments →
- États d’oxydation
- +1, +2 Comparer : États d’oxydation de tous les éléments →
- Électrons de valence
- 2 Comparer : Électrons de valence de tous les éléments →
- Configuration électronique
- [Xe] 6s2
Propriétés thermodynamiques
- Enthalpie de fusion
- 0,07939058 eV Comparer : Enthalpie de fusion de tous les éléments →
- Enthalpie de vaporisation
- 1,461367 eV Comparer : Enthalpie de vaporisation de tous les éléments →
- Enthalpie de sublimation
- 1,865575 eV
- Enthalpie d’atomisation
- 1,865575 eV
- Enthalpie d’atomisation
- 1,856247 eV
Propriétés nucléaires
- Protons
- 56 Comparer : Protons de tous les éléments →
- Neutrons
- 82 Comparer : Neutrons de tous les éléments →
- Isotopes connus
- 42 Comparer : Isotopes connus de tous les éléments →
- Isotopes stables
- 5 Comparer : Isotopes stables de tous les éléments →
- Isotope le plus stable
- Ba-138
- Année de découverte
- 1808
Abondance
- Abondance (croûte terrestre)
- 425 mg/kg Comparer : Abondance (croûte terrestre) de tous les éléments →
- Abondance (océan)
- 0,013 mg/L Comparer : Abondance (océan) de tous les éléments →
Structure cristalline
- Paramètre de maille a
- 502 pm
Structure électronique
- Électrons par couche
- 2, 8, 18, 18, 8, 2 Comparer : Électrons par couche de tous les éléments →
Identifiants
- Numéro CAS
- 7440-39-3 Comparer : Numéro CAS de tous les éléments →
- Symbole de terme
- 1S0
- InChI
- InChI=1S/Ba
- Clé InChI
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N
Configuration électronique Mesuré
Ba: 6s²[Xe] 6s²1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 6s²Modèle atomique
Les isotopes diffèrent par leur nombre de neutrons, leur masse et leur stabilité — pas par la configuration électronique de l’atome neutre.
Modèle atomique schématique, non à l’échelle.
Empreinte atomique
Spectre d’émission / d’absorption
Distribution isotopique
| Nombre de masse | Masse atomique (u) | Abondance naturelle | Demi-vie |
|---|---|---|---|
| 134 Stable | 133,90450818 ± 0,0000003 | 2,4170% | Stable |
| 135 Stable | 134,90568838 ± 0,00000029 | 6,5920% | Stable |
| 136 Stable | 135,90457573 ± 0,00000029 | 7,8540% | Stable |
| 137 Stable | 136,90582714 ± 0,0000003 | 11,2320% | Stable |
| 138 Stable | 137,905247 ± 0,00000031 | 71,6980% | Stable |
Phase / État
Explication: 701,9 °C en dessous du point de fusion (726,85 °C)
Schématique, non à l’échelle
Points de transition de phase
Énergies de transition
Énergie nécessaire pour faire fondre 1 mol au point de fusion
Énergie nécessaire pour vaporiser 1 mol au point d’ébullition
Énergie nécessaire pour sublimer 1 mol au point de sublimation
Masse volumique
Dans les conditions standard
Dans les conditions standard
Spectres atomiques
Affichage de 10 sur 56. Tri par charge ionique croissante.
Raies répertoriées ?
| Ion | Charge | Nombre total de raies | Probabilités de transition | Désignations des niveaux |
|---|---|---|---|---|
| Ba I | 0 | 312 | 109 | 312 |
| Ba II | +1 | 112 | 94 | 112 |
| Ba III | +2 | 535 | 5 | 529 |
| Ba IV | +3 | 42 | 3 | 42 |
| Ba V | +4 | 135 | 0 | 126 |
| Ba VI | +5 | 138 | 0 | 127 |
| Ba VII | +6 | 70 | 0 | 70 |
| Ba VIII | +7 | 141 | 141 | 141 |
| Ba IX | +8 | 110 | 110 | 110 |
| Ba X | +9 | 31 | 31 | 31 |
Niveaux répertoriés ?
| Ion | Charge | Niveaux |
|---|---|---|
| Ba I | 0 | 356 |
| Ba II | +1 | 162 |
| Ba III | +2 | 162 |
| Ba IV | +3 | 34 |
| Ba V | +4 | 52 |
| Ba VI | +5 | 50 |
| Ba VII | +6 | 32 |
| Ba VIII | +7 | 79 |
| Ba IX | +8 | 55 |
| Ba X | +9 | 30 |
Rayons ioniques
| Charge | Coordinence | Spin | Rayon |
|---|---|---|---|
| +2 | 6 | N/D | 135 pm |
| +2 | 7 | N/D | 138 pm |
| +2 | 8 | N/D | 142 pm |
| +2 | 9 | N/D | 147 pm |
| +2 | 10 | N/D | 152 pm |
| +2 | 11 | N/D | 157 pm |
| +2 | 12 | N/D | 161 pm |
Composés
Isotopes (5)
| Nombre de masse | Masse atomique (u) | Abondance naturelle | Demi-vie | Mode de désintégration | |
|---|---|---|---|---|---|
| 134 Stable | 133,90450818 ± 0,0000003 | 2,4170% ± 0,0180% | Stable | stable | |
| 135 Stable | 134,90568838 ± 0,00000029 | 6,5920% ± 0,0120% | Stable | stable | |
| 136 Stable | 135,90457573 ± 0,00000029 | 7,8540% ± 0,0240% | Stable | stable | |
| 137 Stable | 136,90582714 ± 0,0000003 | 11,2320% ± 0,0240% | Stable | stable | |
| 138 Stable | 137,905247 ± 0,00000031 | 71,6980% ± 0,0420% | Stable | stable |
Raies spectrales
Affichage de 50 sur 92. Seules les raies spectrales dont l’intensité a été mesurée sont affichées par défaut.
| Longueur d’onde (nm) | Intensité | Degré d’ionisation | Type | Transition | Précision | Source | |
|---|---|---|---|---|---|---|---|
| 392.686 nm | 25 | Ba III | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | Mesurée | NIST | |
| 399.306 nm | 25 | Ba III | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Mesurée | NIST | |
| 381.3128 nm | 16 | Ba III | emission | 5p5.(2P*<1/2>).6s 2[1/2]* → 5p5.(2P*<1/2>).4f 2[5/2] | Mesurée | NIST | |
| 469.7428 nm | 15 | Ba III | emission | 5p5.(2P*<1/2>).5d 2[3/2]* → 5p5.(2P*<1/2>).6p 2[1/2] | Mesurée | NIST | |
| 448.1646 nm | 14 | Ba III | emission | 5p5.(2P*<1/2>).5d 2[3/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Mesurée | NIST | |
| 610.1987 nm | 13 | Ba III | emission | 5p5.(2P*<1/2>).5d 2[3/2]* → 5p5.(2P*<1/2>).4f 2[5/2] | Mesurée | NIST | |
| 389.6957 nm | 12 | Ba III | emission | 5p5.(2P*<3/2>).5d 2[5/2]* → 5p5.(2P*<3/2>).4f 2[3/2] | Mesurée | NIST | |
| 392.723 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).5d 2[5/2]* → 5p5.(2P*<3/2>).4f 2[9/2] | Mesurée | NIST | |
| 432.793 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | Mesurée | NIST | |
| 482.0642 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[3/2] → 5p5.(2P*<3/2>).5g 2[5/2]* | Mesurée | NIST | |
| 485.0833 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[3/2] → 5p5.(2P*<3/2>).5g 2[5/2]* | Mesurée | NIST | |
| 496.4038 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[5/2] → 5p5.(2P*<3/2>).5g 2[7/2]* | Mesurée | NIST | |
| 504.9533 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[5/2] → 5p5.(2P*<3/2>).5g 2[7/2]* | Mesurée | NIST | |
| 509.7537 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[7/2] → 5p5.(2P*<3/2>).5g 2[9/2]* | Mesurée | NIST | |
| 513.4529 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[7/2] → 5p5.(2P*<3/2>).5g 2[9/2]* | Mesurée | NIST | |
| 599.7996 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[5/2] → 5p5.(2P*<3/2>).7d 2[7/2]* | Mesurée | NIST | |
| 637.7094 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[3/2] → 5p5.(2P*<3/2>).7d 2[5/2]* | Mesurée | NIST | |
| 638.3756 nm | 10 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[5/2] → 5p5.(2P*<3/2>).7d 2[7/2]* | Mesurée | NIST | |
| 438.5824 nm | 9 | Ba III | emission | 5p5.(2P*<1/2>).5d 2[5/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Mesurée | NIST | |
| 464.6207 nm | 9 | Ba III | emission | 5p5.(2P*<3/2>).5d 2[5/2]* → 5p5.(2P*<3/2>).4f 2[3/2] | Mesurée | NIST | |
| 542.699 nm | 9 | Ba III | emission | 5p5.(2P*<1/2>).5d 2[5/2]* → 5p5.(2P*<3/2>).6p 2[5/2] | Mesurée | NIST | |
| 491.7171 nm | 8 | Ba III | emission | 5p5.(2P*<1/2>).5f 2[7/2] → 5p5.(2P*<1/2>).5g 2[9/2]* | Mesurée | NIST | |
| 494.5436 nm | 8 | Ba III | emission | 5p5.(2P*<1/2>).5f 2[5/2] → 5p5.(2P*<1/2>).5g 2[7/2]* | Mesurée | NIST | |
| 495.2914 nm | 8 | Ba III | emission | 5p5.(2P*<1/2>).5f 2[5/2] → 5p5.(2P*<1/2>).5g 2[7/2]* | Mesurée | NIST | |
| 496.3235 nm | 8 | Ba III | emission | 5p5.(2P*<1/2>).5f 2[7/2] → 5p5.(2P*<1/2>).5g 2[9/2]* | Mesurée | NIST | |
| 503.3498 nm | 8 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[5/2] → 5p5.(2P*<3/2>).5g 2[5/2]* | Mesurée | NIST | |
| 503.7341 nm | 8 | Ba III | emission | 5p5.(2P*<1/2>).5d 2[3/2]* → 5p5.(2P*<1/2>).6p 2[1/2] | Mesurée | NIST | |
| 590.0288 nm | 8 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[9/2] → 5p5.(2P*<3/2>).7d 2[7/2]* | Mesurée | NIST | |
| 601.6412 nm | 8 | Ba III | emission | 5p5.(2P*<1/2>).5d 2[3/2]* → 5p5.(2P*<1/2>).6p 2[3/2] | Mesurée | NIST | |
| 603.6589 nm | 8 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[5/2] → 5p5.(2P*<3/2>).7d 2[7/2]* | Mesurée | NIST | |
| 607.7807 nm | 8 | Ba III | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).4f 2[3/2] | Mesurée | NIST | |
| 627.0084 nm | 8 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[3/2] → 5p5.(2P*<3/2>).7d 2[5/2]* | Mesurée | NIST | |
| 652.6166 nm | 8 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[5/2] → 5p5.(2P*<3/2>).8s 2[3/2]* | Mesurée | NIST | |
| 709.5497 nm | 8 | Ba III | emission | 5p5.(2P*<3/2>).6s 2[3/2]* → 5p5.(2P*<3/2>).4f 2[3/2] | Mesurée | NIST | |
| 519.6426 nm | 7 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[5/2] → 5p5.(2P*<3/2>).5g 2[7/2]* | Mesurée | NIST | |
| 552.8138 nm | 7 | Ba III | emission | 5p5.(2P*<1/2>).5d 2[3/2]* → 5p5.(2P*<3/2>).6p 2[1/2] | Mesurée | NIST | |
| 574.0413 nm | 7 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[3/2] → 5p5.(2P*<3/2>).7d 2[7/2]* | Mesurée | NIST | |
| 579.8254 nm | 7 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[5/2] → 5p5.(2P*<3/2>).7d 2[5/2]* | Mesurée | NIST | |
| 585.9192 nm | 7 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[5/2] → 5p5.(2P*<3/2>).7d 2[5/2]* | Mesurée | NIST | |
| 588.1879 nm | 7 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[9/2] → 5p5.(2P*<3/2>).7d 2[7/2]* | Mesurée | NIST | |
| 598.3721 nm | 7 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[1/2] → 5p5.(2P*<3/2>).7d 2[1/2]* | Mesurée | NIST | |
| 658.3333 nm | 7 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[3/2] → 5p5.(2P*<3/2>).7d 2[3/2]* | Mesurée | NIST | |
| 565.8601 nm | 6 | Ba III | emission | 5p5.(2P*<1/2>).5d 2[5/2]* → 5p5.(2P*<3/2>).4f 2[7/2] | Mesurée | NIST | |
| 569.7415 nm | 6 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[3/2] → 5p5.(2P*<3/2>).7d 2[3/2]* | Mesurée | NIST | |
| 571.6614 nm | 6 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[1/2] → 5p5.(2P*<3/2>).7d 2[3/2]* | Mesurée | NIST | |
| 572.6169 nm | 6 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[3/2] → 5p5.(2P*<3/2>).7d 2[3/2]* | Mesurée | NIST | |
| 581.3545 nm | 6 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[3/2] → 5p5.(2P*<3/2>).7d 2[1/2]* | Mesurée | NIST | |
| 607.6665 nm | 6 | Ba III | emission | 5p5.(2P*<3/2>).5f 2[7/2] → 5p5.(2P*<3/2>).7d 2[5/2]* | Mesurée | NIST | |
| 613.1372 nm | 6 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[5/2] → 5p5.(2P*<3/2>).7d 2[1/2]* | Mesurée | NIST | |
| 640.614 nm | 6 | Ba III | emission | 5p5.(2P*<3/2>).7p 2[1/2] → 5p5.(2P*<3/2>).7d 2[3/2]* | Mesurée | NIST |
Propriétés étendues
Rayons covalents (données étendues)
- Rayon covalent (Pyykkö)
- 196 pm
- Rayon covalent (Pyykkö, liaison double)
- 161 pm
- Rayon covalent (Pyykkö, liaison triple)
- 149 pm
- Rayon covalent (Bragg)
- 210 pm
Rayons de van der Waals
- Truhlar
- 268 pm
- Batsanov
- 270 pm
- Alvarez
- 303 pm
- UFF
- 370,3 pm
- MM3
- 307 pm
Rayons atomiques et métalliques
- Rayon atomique (Rahm)
- 293 pm
- Rayon métallique (C12)
- 222 pm
Échelles de numérotation
- Mendeleev
- 9
- Pettifor
- 14
- Glawe
- 14
Échelles d’électronégativité
- Ghosh
- 0
- Miedema
- 2
- Gunnarsson–Lundqvist
- 3
- Robles–Bartolotti
- 2
Polarisabilité et dispersion
- Polarisabilité dipolaire
- 272 a.u.
- Polarisabilité dipolaire (incertitude)
- 10 a.u.
- C₆ (Gould–Bučko)
- 5540 Ha·Bohr6
Paramètres de Miedema
- Volume molaire de Miedema
- 38,1 cm3/mol
- Densité électronique de Miedema
- 1
Risque d’approvisionnement et économie
- Concentration de la production
- 44
- Risque relatif d’approvisionnement
- 8
- Répartition des réserves
- 42
- Stabilité politique (principal producteur)
- 24
- Stabilité politique (principal détenteur de réserves)
- 24
Transitions de phase et allotropes
| Point de fusion | 1000,15 K |
| Point d’ébullition | 2118,15 K |
Catégories d’états d’oxydation
Données de référence avancées
Constantes d’écran (12)
| n | Orbitale | σ |
|---|---|---|
| 1 | s | 1,1139 |
| 2 | p | 4,1904 |
| 2 | s | 14,7532 |
| 3 | d | 13,9757 |
| 3 | p | 18,6836 |
| 3 | s | 18,8444 |
| 4 | d | 32,216 |
| 4 | p | 29,1968 |
| 4 | s | 28,08 |
| 5 | p | 41,1995 |
Détail des rayons cristallins (7)
| Charge | CN | Spin | rcrystal (pm) | Origine |
|---|---|---|---|---|
| 2 | VI | 149 | ||
| 2 | VII | 152 | calculated, | |
| 2 | VIII | 156 | ||
| 2 | IX | 161 | ||
| 2 | X | 166 | ||
| 2 | XI | 171 | ||
| 2 | XII | 175 | calculated, |
Modes de désintégration des isotopes (55)
| Isotope | Mode | Intensité |
|---|---|---|
| 113 | p | — |
| 113 | A | — |
| 114 | B+ | 100% |
| 114 | B+p | 20% |
| 114 | A | 0,9% |
| 114 | 12C | 0% |
| 115 | B+ | 100% |
| 115 | B+p | 15% |
| 116 | B+ | 100% |
| 116 | B+p | 3% |
Facteurs de diffusion des rayons X (508)
| Énergie (eV) | f₁ | f₂ |
|---|---|---|
| 10 | — | 0,10258 |
| 10,1617 | — | 0,10761 |
| 10,3261 | — | 0,11287 |
| 10,4931 | — | 0,1184 |
| 10,6628 | — | 0,1242 |
| 10,8353 | — | 0,13028 |
| 11,0106 | — | 0,13666 |
| 11,1886 | — | 0,14335 |
| 11,3696 | — | 0,15037 |
| 11,5535 | — | 0,15773 |
Données complémentaires
Estimated Crustal Abundance
The estimated element abundance in the earth's crust.
4.25×102 milligrams per kilogram
Références (1)
Estimated Oceanic Abundance
The estimated element abundance in the earth's oceans.
1.3×10-2 milligrams per liter
Références (1)
Sources
Sources of this element.
It is found only in combination with other elements, chiefly with sulfate and carbonate and is prepared by electrolysis of the chloride.
Références (1)
- [6] Barium https://periodic.lanl.gov/56.shtml
Références
(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 Barium.
The element property data was retrieved from publications.