Bismuth | ||||||||||||||||||||||||||||||||||||||||
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Pronunciation | /ˈbɪzməθ/ | |||||||||||||||||||||||||||||||||||||||
Appearance | lustrous brownish silver | |||||||||||||||||||||||||||||||||||||||
Standard atomic weight Ar°(Bi) | ||||||||||||||||||||||||||||||||||||||||
Bismuth in the periodic table | ||||||||||||||||||||||||||||||||||||||||
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Atomic number (Z) | 83 | |||||||||||||||||||||||||||||||||||||||
Group | group 15 (pnictogens) | |||||||||||||||||||||||||||||||||||||||
Period | period 6 | |||||||||||||||||||||||||||||||||||||||
Block | p-block | |||||||||||||||||||||||||||||||||||||||
Electron configuration | [ Xe ] 4f14 5d10 6s2 6p3 | |||||||||||||||||||||||||||||||||||||||
Electrons per shell | 2, 8, 18, 32, 18, 5 | |||||||||||||||||||||||||||||||||||||||
Physical properties | ||||||||||||||||||||||||||||||||||||||||
Phase at STP | solid | |||||||||||||||||||||||||||||||||||||||
Melting point | 544.7 K (271.5 °C,520.7 °F) | |||||||||||||||||||||||||||||||||||||||
Boiling point | 1837 K(1564 °C,2847 °F) | |||||||||||||||||||||||||||||||||||||||
Density (near r.t.) | 9.78 g/cm3 | |||||||||||||||||||||||||||||||||||||||
when liquid (at m.p.) | 10.05 g/cm3 | |||||||||||||||||||||||||||||||||||||||
Heat of fusion | 11.30 kJ/mol | |||||||||||||||||||||||||||||||||||||||
Heat of vaporization | 179 kJ/mol | |||||||||||||||||||||||||||||||||||||||
Molar heat capacity | 25.52 J/(mol·K) | |||||||||||||||||||||||||||||||||||||||
Vapor pressure
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Atomic properties | ||||||||||||||||||||||||||||||||||||||||
Oxidation states | −3, −2, −1, 0, [3] +1, +2, +3, +4, +5 (a mildly acidic oxide) | |||||||||||||||||||||||||||||||||||||||
Electronegativity | Pauling scale: 2.02 | |||||||||||||||||||||||||||||||||||||||
Ionization energies |
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Atomic radius | empirical:156 pm | |||||||||||||||||||||||||||||||||||||||
Covalent radius | 148±4 pm | |||||||||||||||||||||||||||||||||||||||
Van der Waals radius | 207 pm | |||||||||||||||||||||||||||||||||||||||
Spectral lines of bismuth | ||||||||||||||||||||||||||||||||||||||||
Other properties | ||||||||||||||||||||||||||||||||||||||||
Natural occurrence | primordial | |||||||||||||||||||||||||||||||||||||||
Crystal structure | rhombohedral [4] | |||||||||||||||||||||||||||||||||||||||
Speed of sound thin rod | 1790 m/s(at 20 °C) | |||||||||||||||||||||||||||||||||||||||
Thermal expansion | 13.4 µm/(m⋅K)(at 25 °C) | |||||||||||||||||||||||||||||||||||||||
Thermal conductivity | 7.97 W/(m⋅K) | |||||||||||||||||||||||||||||||||||||||
Electrical resistivity | 1.29 µΩ⋅m(at 20 °C) | |||||||||||||||||||||||||||||||||||||||
Magnetic ordering | diamagnetic | |||||||||||||||||||||||||||||||||||||||
Molar magnetic susceptibility | −280.1×10−6 cm3/mol [5] | |||||||||||||||||||||||||||||||||||||||
Young's modulus | 32 GPa | |||||||||||||||||||||||||||||||||||||||
Shear modulus | 12 GPa | |||||||||||||||||||||||||||||||||||||||
Bulk modulus | 31 GPa | |||||||||||||||||||||||||||||||||||||||
Poisson ratio | 0.33 | |||||||||||||||||||||||||||||||||||||||
Mohs hardness | 2.25 | |||||||||||||||||||||||||||||||||||||||
Brinell hardness | 70–95 MPa | |||||||||||||||||||||||||||||||||||||||
CAS Number | 7440-69-9 | |||||||||||||||||||||||||||||||||||||||
History | ||||||||||||||||||||||||||||||||||||||||
Discovery | Arabic alchemists (before AD 1000) | |||||||||||||||||||||||||||||||||||||||
Isotopes of bismuth | ||||||||||||||||||||||||||||||||||||||||
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Bismuth is a chemical element; it has symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs naturally, and its sulfide and oxide forms are important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery-white color when freshly produced. Surface oxidation generally gives samples of the metal a somewhat rosy cast. Further oxidation under heat can give bismuth a vividly iridescent appearance due to thin-film interference. Bismuth is both the most diamagnetic element and one of the least thermally conductive metals known.
Bismuth was long considered the element with the highest atomic mass whose nuclei do not spontaneously decay. However, in 2003 it was discovered to be extremely weakly radioactive. The metal's only primordial isotope, bismuth-209, undergoes alpha decay with a half-life about a billion times the estimated age of the universe. [7] [8]
Bismuth metal has been known since ancient times. Before modern analytical methods bismuth's metallurgical similarities to lead and tin often led it to be confused with those metals. The etymology of "bismuth" is uncertain. The name may come from mid-sixteenth century Neo-Latin translations of the German words weiße Masse or Wismuth, meaning 'white mass', which were rendered as bisemutum or bisemutium.
Bismuth compounds account for about half the global production of bismuth. They are used in cosmetics; pigments; and a few pharmaceuticals, notably bismuth subsalicylate, used to treat diarrhea. [8] Bismuth's unusual propensity to expand as it solidifies is responsible for some of its uses, as in the casting of printing type. [8] Bismuth, when in its elemental form, has unusually low toxicity for a heavy metal. [8] As the toxicity of lead and the cost of its environmental remediation became more apparent during the 20th century, suitable bismuth alloys have gained popularity as replacements for lead. Presently, around a third of global bismuth production is dedicated to needs formerly met by lead.
Bismuth metal has been known since ancient times and it was one of the first 10 metals to have been discovered. The name bismuth dates to around 1665 and is of uncertain etymology. The name possibly comes from obsolete German Bismuth, Wismut, Wissmuth (early 16th century), perhaps related to Old High German hwiz ("white"). [9] The Neo-Latin bisemutium (coined by Georgius Agricola, who Latinized many German mining and technical words) is from the German Wismuth, itself perhaps from weiße Masse, meaning "white mass". [10] [11]
The element was confused in early times with tin and lead because of its resemblance to those elements. Because bismuth has been known since ancient times, no one person is credited with its discovery. Agricola (1546) states that bismuth is a distinct metal in a family of metals including tin and lead. This was based on observation of the metals and their physical properties. [12]
Miners in the age of alchemy also gave bismuth the name tectum argenti, or "silver being made" in the sense of silver still in the process of being formed within the Earth. [13] [14] [15]
Bismuth was also known to the Incas and used (along with the usual copper and tin) in a special bronze alloy for knives. [16]
Beginning with Johann Heinrich Pott in 1738, [17] Carl Wilhelm Scheele, and Torbern Olof Bergman, the distinctness of lead and bismuth became clear, and Claude François Geoffroy demonstrated in 1753 that this metal is distinct from lead and tin. [14] [18] [19]
Bismuth is a brittle metal with a dark, silver-pink hue, often with an iridescent oxide tarnish showing many colors from yellow to blue. The spiral, stair-stepped structure of bismuth crystals is the result of a higher growth rate around the outside edges than on the inside edges. The variations in the thickness of the oxide layer that forms on the surface of the crystal cause different wavelengths of light to interfere upon reflection, thus displaying a rainbow of colors. When burned in oxygen, bismuth burns with a blue flame and its oxide forms yellow fumes. [18] Its toxicity is much lower than that of its neighbors in the periodic table, such as lead and antimony. [20]
No other metal is verified to be more naturally diamagnetic than bismuth. [18] [21] (Superdiamagnetism is a different physical phenomenon.) Of any metal, it has one of the lowest values of thermal conductivity (after manganese, neptunium and plutonium) and the highest Hall coefficient. [22] It has a high electrical resistivity. [18] When deposited in sufficiently thin layers on a substrate, bismuth is a semiconductor, despite being a post-transition metal. [23] Elemental bismuth is denser in the liquid phase than the solid, a characteristic it shares with germanium, silicon, gallium, and water. [24] Bismuth expands 3.32% on solidification; therefore, it was long a component of low-melting typesetting alloys, where it compensated for the contraction of the other alloying components [18] [25] [26] [27] to form almost isostatic bismuth-lead eutectic alloys.
Though virtually unseen in nature, high-purity bismuth can form distinctive, colorful hopper crystals. It is relatively nontoxic and has a low melting point just above 271 °C, so crystals may be grown using a household stove, although the resulting crystals will tend to be of lower quality than lab-grown crystals. [28]
At ambient conditions, bismuth shares the same layered structure as the metallic forms of arsenic and antimony, [29] crystallizing in the rhombohedral lattice [30] (Pearson symbol hR6, space group R3m No. 166) of the trigonal crystal system. [4] When compressed at room temperature, this Bi-I structure changes first to the monoclinic Bi-II at 2.55 GPa, then to the tetragonal Bi-III at 2.7 GPa, and finally to the body-centered cubic Bi-V at 7.7 GPa. The corresponding transitions can be monitored via changes in electrical conductivity; they are rather reproducible and abrupt and are therefore used for calibration of high-pressure equipment. [31] [32]
Bismuth is stable to both dry and moist air at ordinary temperatures. When red-hot, it reacts with water to make bismuth(III) oxide. [33]
It reacts with fluorine to make bismuth(V) fluoride at 500 °C or bismuth(III) fluoride at lower temperatures (typically from Bi melts); with other halogens it yields only bismuth(III) halides. [34] [35] [36] The trihalides are corrosive and easily react with moisture, forming oxyhalides with the formula BiOX. [37]
Bismuth dissolves in concentrated sulfuric acid to make bismuth(III) sulfate and sulfur dioxide. [33]
It reacts with nitric acid to make bismuth(III) nitrate (which decomposes into nitrogen dioxide when heated [38] ). [39]
It also dissolves in hydrochloric acid, but only with oxygen present. [33]
The only primordial isotope of bismuth, bismuth-209, was traditionally regarded as the heaviest stable isotope, but it had long been suspected [40] to be unstable on theoretical grounds. This was finally demonstrated in 2003, when researchers at the Institut d'Astrophysique Spatiale in Orsay, France, measured the alpha emission half-life of 209
Bi
to be 2.01×1019 years (3 Bq/M g), [41] [42] over a billion times longer than the current estimated age of the universe. [8] Owing to its extraordinarily long half-life, for all presently known medical and industrial applications, bismuth can be treated as if it is stable and nonradioactive. The radioactivity is of academic interest because bismuth is one of a few elements whose radioactivity was suspected and theoretically predicted before being detected in the laboratory. [8] Bismuth has the longest known alpha decay half-life, although tellurium-128 has a double beta decay half-life of over 2.2×1024 years. [42] Bismuth's extremely long half-life means that less than approximately one-billionth of the bismuth present at the formation of the planet Earth would have decayed into thallium since then.
Six isotopes of bismuth with short half-lives (210 through 215 inclusive) occur within the natural radioactive disintegration chains of actinium, radium, thorium, and neptunium, and more have been synthesized experimentally. (Although all primordial 237Np has long since decayed, it is continually regenerated by (n,2n) knockout reactions on natural 238U.) [43] [44]
Commercially, the radioactive isotope bismuth-213 can be produced by bombarding radium with bremsstrahlung photons from a linear particle accelerator. In 1997, an antibody conjugate with bismuth-213, which has a 45-minute half-life and decays with the emission of an alpha particle, was used to treat patients with leukemia. This isotope has also been tried in cancer treatment, for example, in the targeted alpha therapy (TAT) program. [45] [46]
Bismuth forms trivalent and pentavalent compounds, the trivalent ones being more common. Many of its chemical properties are similar to those of arsenic and antimony, although they are less toxic than derivatives of those lighter elements. [20]
At elevated temperatures, the vapors of the metal combine rapidly with oxygen, forming the yellow trioxide, Bi
2O
3. [24] [47] When molten, at temperatures above 710 °C, this oxide corrodes any metal oxide and even platinum. [36] On reaction with a base, it forms two series of oxyanions: BiO−
2, which is polymeric and forms linear chains, and BiO3−
3. The anion in Li
3BiO
3 is a cubic octameric anion, Bi
8O24−
24, whereas the anion in Na
3BiO
3 is tetrameric. [48]
The dark red bismuth pentoxide, Bi
2O
5, is unstable, liberating O
2 gas upon heating. [49] The compound NaBiO3 is a strong oxidising agent. [50]
Bismuth sulfide, Bi
2S
3, occurs naturally in bismuth ores. [51] It is also produced by the combination of molten bismuth and sulfur. [35]
Bismuth oxychloride (BiOCl, see figure at right) and bismuth oxynitrate (BiONO3) stoichiometrically appear as simple anionic salts of the bismuthyl(III) cation (BiO+) which commonly occurs in aqueous bismuth compounds. However, in the case of BiOCl, the salt crystal forms in a structure of alternating plates of Bi, O, and Cl atoms, with each oxygen coordinating with four bismuth atoms in the adjacent plane. This mineral compound is used as a pigment and cosmetic (see below). [52]
Unlike the lighter pnictogens nitrogen, phosphorus, and arsenic, but similar to antimony, bismuth does not form a stable hydride. Bismuth hydride, bismuthine (BiH
3), is an endothermic compound that spontaneously decomposes at room temperature. It is stable only below −60 °C. [48] Bismuthides are intermetallic compounds between bismuth and other metals, [53] such as neodymium. [54]
In 2014 researchers discovered that sodium bismuthide can exist as a form of matter called a “three-dimensional topological Dirac semi-metal” (3DTDS) that possess 3D Dirac fermions in bulk. It is a natural, three-dimensional counterpart to graphene with similar electron mobility and velocity. Graphene and topological insulators (such as those in 3DTDS) are both crystalline materials that are electrically insulating inside but conducting on the surface, allowing them to function as transistors and other electronic devices. While sodium bismuthide (Na
3Bi) is too unstable to be used in devices without packaging, it can demonstrate potential applications of 3DTDS systems, which offer distinct efficiency and fabrication advantages over planar graphene in semiconductor and spintronics applications. [55] [56]
The halides of bismuth in low oxidation states have been shown to adopt unusual structures. What was originally thought to be bismuth(I) chloride, BiCl, turns out to be a complex compound consisting of Bi5+
9 cations and BiCl2−
5 and Bi
2Cl2−
8 anions. [48] [57] The Bi5+
9 cation has a distorted tricapped trigonal prismatic molecular geometry and is also found in Bi
10Hf
3Cl
18, which is prepared by reducing a mixture of hafnium(IV) chloride and bismuth chloride with elemental bismuth, having the structure [Bi+
] [Bi5+
9] [HfCl2−
6]
3. [48] : 50 Other polyatomic bismuth cations are also known, such as Bi2+
8, found in Bi
8(AlCl
4)
2. [57] Bismuth also forms a low-valence bromide with the same structure as BiCl. There is a true monoiodide, BiI, which contains chains of Bi
4I
4 units. BiI decomposes upon heating to the triiodide, BiI
3, and elemental bismuth. A monobromide of the same structure also exists. [48] In oxidation state +3, bismuth forms trihalides with all of the halogens: BiF
3, BiCl
3, BiBr
3, and BiI
3. All of these except BiF
3 are hydrolyzed by water. [48]
Bismuth(III) chloride reacts with hydrogen chloride in ether solution to produce the acid HBiCl
4. [33]
The oxidation state +5 is less frequently encountered. One such compound is BiF
5, a powerful oxidizing and fluorinating agent. It is also a strong fluoride acceptor, reacting with xenon tetrafluoride to form the XeF+
3 cation: [33]
In aqueous solution, the Bi3+
ion is solvated to form the aqua ion Bi(H
2O)3+
8 in strongly acidic conditions. [58] At pH > 0 polynuclear species exist, the most important of which is believed to be the octahedral complex [Bi
6O
4(OH)
4]6+
. [59]
In the Earth's crust, bismuth is about twice as abundant as gold. The most important ores of bismuth are bismuthinite and bismite. [18] Native bismuth is known from Australia, Bolivia, and China. [60] [61]
Country | Refining [62] |
---|---|
China | 16,000 |
Laos | 2,000 |
South Korea | 950 |
Japan | 480 |
Kazakhstan | 220 |
Other | 350 |
Total | 20,000 |
According to the United States Geological Survey (USGS), 10,200 tonnes of bismuth were produced worldwide by mining and 17,100 tonnes by refining in 2016. Since then, USGS does not provide mining data for bismuth, considering them unreliable. Globally, bismuth is mostly produced by refining, as a byproduct of extraction of other metals such as lead, copper, tin, molybdenum and tungsten, though the refining-to-mining ratio depends on the country. [63] [64] [65] [66]
Bismuth travels in crude lead bullion (which can contain up to 10% bismuth) through several stages of refining, until it is removed by the Kroll-Betterton process which separates the impurities as slag, or the electrolytic Betts process. Bismuth will behave similarly with another of its major metals, copper. [64] The raw bismuth metal from both processes contains still considerable amounts of other metals, foremost lead. By reacting the molten mixture with chlorine gas the metals are converted to their chlorides while bismuth remains unchanged. Impurities can also be removed by various other methods for example with fluxes and treatments yielding high-purity bismuth metal (over 99% Bi). [67]
The price for pure bismuth metal has been relatively stable through most of the 20th century, except for a spike in the 1970s. Bismuth has always been produced mainly as a byproduct of lead refining, and thus the price usually reflected the cost of recovery and the balance between production and demand. [68]
Prior to World War II, demand for bismuth was small and mainly pharmaceutical — bismuth compounds were used to treat such conditions as digestive disorders, sexually transmitted diseases and burns. Minor amounts of bismuth metal were consumed in fusible alloys for fire sprinkler systems and fuse wire. During World War II bismuth was considered a strategic material, used for solders, fusible alloys, medications and atomic research. To stabilize the market, the producers set the price at $1.25 per pound ($2.75 /kg) during the war and at $2.25 per pound ($4.96 /kg) from 1950 until 1964. [68]
In the early 1970s, the price rose rapidly as a result of increasing demand for bismuth as a metallurgical additive to aluminium, iron and steel. This was followed by a decline owing to increased world production, stabilized consumption, and the recessions of 1980 and 1981–1982. In 1984, the price began to climb as consumption increased worldwide, especially in the United States and Japan. In the early 1990s, research began on the evaluation of bismuth as a nontoxic replacement for lead in ceramic glazes, fishing sinkers, food-processing equipment, free-machining brasses for plumbing applications, lubricating greases, and shot for waterfowl hunting. [69] Growth in these areas remained slow during the middle 1990s, in spite of the backing of lead replacement by the United States federal government, but intensified around 2005. This resulted in a rapid and continuing increase in price. [68]
Most bismuth is produced as a byproduct of other metal-extraction processes including the smelting of lead, and also of tungsten and copper. Its sustainability is dependent on increased recycling, which is problematic. [70]
It was once believed that bismuth could be practically recycled from the soldered joints in electronic equipment. Recent efficiencies in solder application in electronics mean there is substantially less solder deposited, and thus less to recycle. While recovering the silver from silver-bearing solder may remain economic, recovering bismuth is substantially less so. [71]
Dispersed bismuth is used in certain stomach medicines (bismuth subsalicylate), paints (bismuth vanadate), pearlescent cosmetics (bismuth oxychloride), and bismuth-containing bullets. Recycling bismuth from these uses is impractical. [67]
Bismuth has few commercial applications, and those applications that use it generally require small quantities relative to other raw materials. In the United States, for example, 733 tonnes of bismuth were consumed in 2016, of which 70% went into chemicals (including pharmaceuticals, pigments, and cosmetics) and 11% into bismuth alloys. [67]
In the early 1990s, researchers began to evaluate bismuth as a nontoxic replacement for lead in various applications. [67]
Bismuth is an ingredient in some pharmaceuticals, [8] although the use of some of these substances is declining. [52]
Bismuth oxychloride (BiOCl) is sometimes used in cosmetics, as a pigment in paint for eye shadows, hair sprays and nail polishes. [8] [52] [83] [84] This compound is found as the mineral bismoclite and in crystal form contains layers of atoms (see figure above) that refract light chromatically, resulting in an iridescent appearance similar to nacre of pearl. It was used as a cosmetic in ancient Egypt and in many places since. Bismuth white (also "Spanish white") can refer to either bismuth oxychloride or bismuth oxynitrate (BiONO3), when used as a white pigment. [85] Bismuth vanadate is used as a light-stable non-reactive paint pigment (particularly for artists' paints), often as a replacement for the more toxic cadmium sulfide yellow and orange-yellow pigments. The most common variety in artists' paints is a lemon yellow, visually indistinguishable from its cadmium-containing alternative. [86]
Bismuth is used in alloys with other metals such as tin and lead. Wood's metal, an alloy of bismuth, lead, tin, and cadmium is used in automatic sprinkler systems for fires. It forms the largest part (50%) of Rose's metal, a fusible alloy, which also contains 25–28% lead and 22–25% tin. It was also used to make bismuth bronze which was used in the Bronze Age, having been found in Inca knives at Machu Picchu. [87]
The density difference between lead (11.32 g/cm3) and bismuth (9.78 g/cm3) is small enough that for many ballistics and weighting applications, bismuth can substitute for lead. For example, it can replace lead as a dense material in fishing sinkers. It has been used as a replacement for lead in shot, bullets and less-lethal riot gun ammunition. The Netherlands, Denmark, England, Wales, the United States, and many other countries now prohibit the use of lead shot for the hunting of wetland birds, as many birds are prone to lead poisoning owing to mistaken ingestion of lead (instead of small stones and grit) to aid digestion, or even prohibit the use of lead for all hunting, such as in the Netherlands. Bismuth-tin alloy shot is one alternative that provides similar ballistic performance to lead. [67]
Bismuth, as a dense element of high atomic weight, is used in bismuth-impregnated latex shields to shield from X-ray in medical examinations, such as CTs, mostly as it is considered non-toxic. [88]
The European Union's Restriction of Hazardous Substances Directive (RoHS) for reduction of lead has broadened bismuth's use in electronics as a component of low-melting point solders, as a replacement for traditional tin-lead solders. [67] Its low toxicity will be especially important for solders to be used in food processing equipment and copper water pipes, although it can also be used in other applications including those in the automobile industry, in the European Union, for example. [89]
Bismuth has been evaluated as a replacement for lead in free-machining brasses for plumbing applications, [90] although it does not equal the performance of leaded steels. [89]
Many bismuth alloys have low melting points and are found in specialty applications such as solders. Many automatic sprinklers, electric fuses, and safety devices in fire detection and suppression systems contain the eutectic In19.1-Cd5.3-Pb22.6-Sn8.3-Bi44.7 alloy that melts at 47 °C (117 °F) [18] This is a convenient temperature since it is unlikely to be exceeded in normal living conditions. Low-melting alloys, such as Bi-Cd-Pb-Sn alloy which melts at 70 °C, are also used in automotive and aviation industries. Before deforming a thin-walled metal part, it is filled with a melt or covered with a thin layer of the alloy to reduce the chance of breaking. Then the alloy is removed by submerging the part in boiling water. [91]
Bismuth is used to make free-machining steels and free-machining aluminium alloys for precision machining properties. It has similar effect to lead and improves the chip breaking during machining. The shrinking on solidification in lead and the expansion of bismuth compensate each other and therefore lead and bismuth are often used in similar quantities. [92] [93] Similarly, alloys containing comparable parts of bismuth and lead exhibit a very small change (on the order 0.01%) upon melting, solidification or aging. Such alloys are used in high-precision casting, e.g. in dentistry, to create models and molds. [91] Bismuth is also used as an alloying agent in production of malleable irons [67] and as a thermocouple material. [18]
Bismuth is also used in aluminium-silicon cast alloys in order to refine silicon morphology. However, it indicated a poisoning effect on modification of strontium. [94] [95] Some bismuth alloys, such as Bi35-Pb37-Sn25, are combined with non-sticking materials such as mica, glass and enamels because they easily wet them allowing to make joints to other parts. Addition of bismuth to caesium enhances the quantum yield of caesium cathodes. [52] Sintering of bismuth and manganese powders at 300 °C produces a permanent magnet and magnetostrictive material, which is used in ultrasonic generators and receivers working in the 10–100 kHz range and in magnetic and holographic memory devices. [96]
Scientific literature indicates that some of the compounds of bismuth are less toxic to humans via ingestion than other heavy metals (lead, arsenic, antimony, etc.) [8] presumably due to the comparatively low solubility of bismuth salts. [108] Its biological half-life for whole-body retention is reported to be 5 days but it can remain in the kidney for years in people treated with bismuth compounds. [109]
Bismuth poisoning can occur and has according to some reports been common in relatively recent times. [108] [110] As with lead, bismuth poisoning can result in the formation of a black deposit on the gingiva, known as a bismuth line. [111] [112] [113] Poisoning may be treated with dimercaprol; however, evidence for benefit is unclear. [114] [115]
Bismuth's environmental impacts are not well known; it may be less likely to bioaccumulate than some other heavy metals, and this is an area of active research. [116] [117]
Antimony is a chemical element; it has symbol Sb (from Latin stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name kohl. The earliest known description of the metalloid in the West was written in 1540 by Vannoccio Biringuccio.
Indium is a chemical element; it has symbol In and atomic number 49. It is a silvery-white post-transition metal and one of the softest elements. Chemically, indium is similar to gallium and thallium, and its properties are largely intermediate between the two. It was discovered in 1863 by Ferdinand Reich and Hieronymous Theodor Richter by spectroscopic methods and named for the indigo blue line in its spectrum.
A metal is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically ductile and malleable. These properties are the result of the metallic bond between the atoms or molecules of the metal.
Solder is a fusible metal alloy used to create a permanent bond between metal workpieces. Solder is melted in order to wet the parts of the joint, where it adheres to and connects the pieces after cooling. Metals or alloys suitable for use as solder should have a lower melting point than the pieces to be joined. The solder should also be resistant to oxidative and corrosive effects that would degrade the joint over time. Solder used in making electrical connections also needs to have favorable electrical characteristics.
Tin is a chemical element; it has symbol Sn and atomic number 50. A silvery-coloured metal, tin is soft enough to be cut with little force, and a bar of tin can be bent by hand with little effort. When bent, the so-called "tin cry" can be heard as a result of twinning in tin crystals; this trait is shared by indium, cadmium, zinc, and mercury in its solid state.
A metalloid is a type of chemical element which has a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals. There is no standard definition of a metalloid and no complete agreement on which elements are metalloids. Despite the lack of specificity, the term remains in use in the literature of chemistry.
A period 5 element is one of the chemical elements in the fifth row of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall into the same vertical columns. The fifth period contains 18 elements, beginning with rubidium and ending with xenon. As a rule, period 5 elements fill their 5s shells first, then their 4d, and 5p shells, in that order; however, there are exceptions, such as rhodium.
A period 6 element is one of the chemical elements in the sixth row (or period) of the periodic table of the chemical elements, including the lanthanides. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall into the same vertical columns. The sixth period contains 32 elements, tied for the most with period 7, beginning with caesium and ending with radon. Lead is currently the last stable element; all subsequent elements are radioactive. For bismuth, however, its only primordial isotope, 209Bi, has a half-life of more than 1019 years, over a billion times longer than the current age of the universe. As a rule, period 6 elements fill their 6s shells first, then their 4f, 5d, and 6p shells, in that order; however, there are exceptions, such as gold.
A pnictogen is any of the chemical elements in group 15 of the periodic table. Group 15 is also known as the nitrogen group or nitrogen family. Group 15 consists of the elements nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), bismuth (Bi), and moscovium (Mc).
Antimony(III) oxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite. Like most polymeric oxides, Sb2O3 dissolves in aqueous solutions with hydrolysis. A mixed arsenic-antimony oxide occurs in nature as the very rare mineral stibioclaudetite.
The oligodynamic effect is a biocidal effect of metals, especially heavy metals, that occurs even in low concentrations. This effect is attributed to the antibacterial behavior of metal ions, which are absorbed by bacteria upon contact and damage their cell membranes.
Trimethylarsine (abbreviated TMA or TMAs) is the chemical compound with the formula (CH3)3As, commonly abbreviated AsMe3 or TMAs. This organic derivative of arsine has been used as a source of arsenic in microelectronics industry, a building block to other organoarsenic compounds, and serves as a ligand in coordination chemistry. It has distinct "garlic"-like smell. Trimethylarsine had been discovered as early as 1854.
Metal toxicity or metal poisoning is the toxic effect of certain metals in certain forms and doses on life. Some metals are toxic when they form poisonous soluble compounds. Certain metals have no biological role, i.e. are not essential minerals, or are toxic when in a certain form. In the case of lead, any measurable amount may have negative health effects. It is often thought that only heavy metals can be toxic, but lighter metals such as beryllium and lithium may also be in certain circumstances. Not all heavy metals are particularly toxic, and some are essential, such as iron. The definition may also include trace elements when abnormally high doses may be toxic. An option for treatment of metal poisoning may be chelation therapy, a technique involving the administration of chelation agents to remove metals from the body.
Bismuth oxynitrate is the name applied to a number of compounds that contain Bi3+, nitrate ions and oxide ions and which can be considered as compounds formed from Bi2O3, N2O5 and H2O. Other names for bismuth oxynitrate include bismuth subnitrate and bismuthyl nitrate. In older texts bismuth oxynitrate is often simply described as BiONO3 or basic bismuth nitrate. Bismuth oxynitrate was once called magisterium bismuti or bismutum subnitricum, and was used as a white pigment, in beauty care, and as a gentle disinfectant for internal and external use. It is also used to form Dragendorff's reagent, which is used as a TLC stain.
The metallic elements in the periodic table located between the transition metals to their left and the chemically weak nonmetallic metalloids to their right have received many names in the literature, such as post-transition metals, poor metals, other metals, p-block metals and chemically weak metals. The most common name, post-transition metals, is generally used in this article.
Solder is a metallic material that is used to connect metal workpieces. The choice of specific solder alloys depends on their melting point, chemical reactivity, mechanical properties, toxicity, and other properties. Hence a wide range of solder alloys exist, and only major ones are listed below. Since early 2000s the use of lead in solder alloys is discouraged by several governmental guidelines in the European Union, Japan and other countries, such as Restriction of Hazardous Substances Directive and Waste Electrical and Electronic Equipment Directive.
Compounds of arsenic resemble in some respects those of phosphorus which occupies the same group (column) of the periodic table. The most common oxidation states for arsenic are: −3 in the arsenides, which are alloy-like intermetallic compounds, +3 in the arsenites, and +5 in the arsenates and most organoarsenic compounds. Arsenic also bonds readily to itself as seen in the square As3−
4 ions in the mineral skutterudite. In the +3 oxidation state, arsenic is typically pyramidal owing to the influence of the lone pair of electrons.
Bismuth compounds are compounds containing the element bismuth (Bi). Bismuth forms trivalent and pentavalent compounds, the trivalent ones being more common. Many of its chemical properties are similar to those of arsenic and antimony, although they are less toxic than derivatives of those lighter elements.
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: CS1 maint: location missing publisher (link)This article incorporates text from this source, which is in the public domain : Brown, R. D., Jr. "Annual Average Bismuth Price", USGS (1998)