{{About|the chemical element|other uses}} {{Good article}} {{Use dmy dates|date=January 2015}} {{infobox bismuth}} '''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 the most diamagnetic element and of all the metals, it is among the most electrically resistive and least thermally conductive known.

Bismuth was formerly understood to be the element with the highest atomic mass whose nuclei do not spontaneously decay, but in 2003, it was found to be very slightly radioactive. The metal's only primordial isotope, bismuth-209, undergoes alpha decay with a half-life roughly a billion times longer than the estimated age of the universe.<ref>{{cite news| url=http://physicsworld.com/cws/article/news/2003/apr/23/bismuth-breaks-half-life-record-for-alpha-decay| title=Bismuth breaks half-life record for alpha decay| date=23 April 2003| publisher=Physicsworld| first=Belle| last= Dumé}}</ref><ref name="Kean">{{cite book|last=Kean|first=Sam|title=The Disappearing Spoon (and other true tales of madness, love, and the history of the world from the Periodic Table of Elements)|publisher=Back Bay Books |location=New York/Boston|year=2011|pages=158–160|isbn=978-0-316-051637}}</ref>

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-16th-century neo-Latin translations of the German words {{lang|de|weiße Masse}} or {{lang|de|Wismuth}}, meaning "white mass", which were rendered as {{lang|la|bisemutum}} or {{lang|la|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.<ref name="Kean" /> Bismuth's unusual propensity to expand as it solidifies is responsible for some of its uses, as in the casting of printing type.<ref name="Kean" /> Bismuth, when in its elemental form, has unusually low toxicity for a heavy metal.<ref name="Kean" /> 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.

== History and etymology== Bismuth was one of the first 11 metals to have been discovered. The name "bismuth" dates to around 1665 and is of uncertain etymology. The name possibly comes from German ''{{lang|de|Bismuth}}'', ''{{lang|de|Wismut}}'', ''{{lang|de|Wissmuth}}'' (early 16th century), perhaps related to Old High German ''{{lang|goh|hwiz}}'' ("white").<ref name="oet">{{OEtymD|bismuth}}</ref> The Neo-Latin ''{{lang|la|bisemutium}}'' (coined by Georgius Agricola, who Latinized many German mining and technical words) is from the German ''{{lang|de|Wismuth}}'', itself perhaps from ''{{lang|de|weiße Masse}}'', meaning "white mass".<ref>{{cite book |title=The Concise Oxford Dictionary of English Etymology |date=1996 |doi=10.1093/acref/9780192830982.001.0001 |isbn=978-0-19-283098-2 |editor1-first=T. F. |editor1-last=Hoad |chapter=bismuth |chapter-url=https://www.oxfordreference.com/view/10.1093/acref/9780192830982.001.0001/acref-9780192830982-e-1517 }}</ref><ref name="Norman">{{cite book |last=Norman |first=Nicholas C. |date=1998 |title=Chemistry of Arsenic, Antimony, and Bismuth |page=41 |publisher=Springer |isbn=978-0-7514-0389-3 |url=https://books.google.com/books?id=vVhpurkfeN4C&pg=PA41}}</ref>

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.<ref>{{cite book |last=Agricola |first=Georgious |orig-year=1546 |date=1955 |title=De Natura Fossilium |location=New York |publisher=Mineralogical Society of America |page=178 |url=http://farlang.com/books/agricola-bandy-de-natura-fossilium |access-date=8 April 2019 |archive-date=14 May 2021 |archive-url=https://web.archive.org/web/20210514044323/http://farlang.com/books/agricola-bandy-de-natura-fossilium |url-status=dead }} <!-- https://books.google.com/books?id=9pxPAAAAcAAJ&pg=PA143 --></ref> Miners in the age of alchemy also gave bismuth the name ''{{lang|la|tectum argenti}},'' or "silver being made" in the sense of silver still in the process of being formed within the Earth.<ref>{{cite book |last=Nicholson |first=William |date=1819 |chapter=Bismuth |title=American edition of the British encyclopedia: Or, Dictionary of Arts and sciences; comprising an accurate and popular view of the present improved state of human knowledge |page=181 |chapter-url=https://books.google.com/books?id=GL5PAAAAMAAJ&pg=PT181}}</ref><ref name="Weeks">{{cite journal |last=Weeks |first=Mary Elvira |author-link=Mary Elvira Weeks |date=1932 |title=The discovery of the elements. II. Elements known to the alchemists |journal=Journal of Chemical Education |volume=9 |issue=1 |page=11 |doi=10.1021/ed009p11 |bibcode=1932JChEd...9...11W}}</ref><ref>{{cite web |last=Giunta |first=Carmen J. |url=http://web.lemoyne.edu/~giunta/archems.html |title=Glossary of Archaic Chemical Terms |publisher=Le Moyne College}} See also for other terms for bismuth, including ''stannum glaciale'' (glacial tin or ice-tin).</ref> Bismuth was also known to the Incas and used (along with the usual copper and tin) in a special bronze alloy for knives.<ref>{{cite journal |last1 = Gordon | first1= Robert B. |last2 = Rutledge | first2= John W. |date = 1984 |title = Bismuth Bronze from Machu Picchu, Peru |journal = Science |volume = 223 |issue = 4636 |pages = 585–586 |doi = 10.1126/science.223.4636.585 |pmid = 17749940 |bibcode = 1984Sci...223..585G |s2cid = 206572055 |jstor = 1692247}}</ref>

[[File:Bismuth symbol.svg|thumb|upright=0.5|right|Alchemical symbol used by Torbern Bergman (1775)]] Beginning with Johann Heinrich Pott in 1738,<ref>{{cite book |last=Pott |first=Johann Heinrich |date=1738 |chapter=De Wismutho |title=Exercitationes Chymicae |page=134 |publisher=Berolini: Apud Johannem Andream Rüdigerum |chapter-url=https://books.google.com/books?id=eQVAAAAAcAAJ&pg=RA1-PA134}}</ref> 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.<ref name="Weeks" /><ref name="CRC" /><ref>{{cite journal |author-link=Claude François Geoffroy |last=Geoffroy |first=C.F. |title = Sur Bismuth |page = 190 |date = 1753 |journal = Histoire de l'Académie Royale des Sciences ... Avec les Mémoires de Mathématique & de Physique ... Tirez des Registres de Cette Académie |url = http://gallica.bnf.fr/ark:/12148/bpt6k3551g/f197.image.r=royal.langEN}}</ref>

== Characteristics == [[File:Wismut Kristall und 1cm3 Wuerfel.jpg|thumb|left|upright=1.2|Left: A bismuth hopper crystal is exhibiting the stairstep crystal structure and iridescent colors, which are produced by interference of light within the oxide film on its surface. Right: a 1&nbsp;cm<sup>3</sup> cube of unoxidised bismuth metal]]

=== Physical characteristics === thumb|left|upright=1.2|Pressure-temperature phase diagram of bismuth. ''T''<sub>C</sub> refers to the superconducting transition temperature 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.<ref name="CRC" /> Its toxicity is much lower than that of its neighbors in the periodic table, such as lead and antimony.<ref name=tox/>

No other metal is verified to be more naturally diamagnetic than bismuth.<ref name="CRC" /><ref name="Ullmanns">{{Ullmann|last1=Krüger |first1=Joachim |last2=Winkler |first2=Peter |last3=Lüderitz |first3=Eberhard |last4=Lück |first4=Manfred |last5=Wolf |first5=Hans Uwe |title=Bismuth, Bismuth Alloys, and Bismuth Compounds |doi=10.1002/14356007.a04_171}}</ref>{{rp|171}}{{efn|name=fn2|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.<ref>{{cite journal| doi = 10.1098/rspa.1936.0126 |jstor = 96773| title = The Theory of the Galvomagnetic Effects in Bismuth| date = 1936| last1 = Jones| first1 = H.| journal = Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences| volume = 155| issue = 886|pages = 653–663|bibcode = 1936RSPSA.155..653J| doi-access = free}}</ref> It has the fourth highest electrical resistivity of all the pure metals, only surpassed by gadolinium, manganese and plutonium.<ref name="CRC">{{cite book| first = C. R.| last = Hammond| pages = 4.1, 12.45{{endash}}47 |url=https://archive.org/details/crchandbookofche81lide/page/n13| title = The Elements, in Handbook of Chemistry and Physics| edition = 81st| location = Boca Raton (FL, US)| publisher = CRC press| isbn = 978-0-8493-0485-9| date = 2004| url-access = registration}}</ref><ref name="LNG">{{cite book| first = J. A.| last = Dean| pages = 4.1{{endash}}4.5 | title = Lange's Handbook of Chemistry | edition = 15th| publisher = McGraw-Hill | isbn = 0070163847| date = 1999}}</ref>{{efn|name=fn3|When measured at approximately room temperature.}} When deposited in sufficiently thin layers on a substrate, bismuth is a semiconductor, despite being a post-transition metal.<ref>{{cite journal| title = Semimetal-to-semiconductor transition in bismuth thin films|journal = Phys. Rev. B|volume =48|date =1993|doi =10.1103/PhysRevB.48.11431|pmid = 10007465|bibcode = 1993PhRvB..4811431H| issue = 15|pages = 11431–11434| last1 = Hoffman| first1 = C.| last2 = Meyer| first2 = J.| last3 = Bartoli| first3 = F.| last4 = Di Venere| first4 = A.| last5 = Yi| first5 = X.| last6 = Hou| first6 = C.| last7 = Wang| first7 = H.| last8 = Ketterson| first8 = J.| last9 = Wong| first9 = G.}}</ref> Elemental bismuth is denser in the liquid phase than the solid, a characteristic it shares with germanium, silicon, gallium, plutonium, and water.<ref name="Wiberg">{{cite book |title=Inorganic chemistry |last1=Wiberg |first1=Egon |last2=Holleman |first2=A. F. |last3=Wiberg |first3=Nils |publisher=Academic Press |date=2001 |isbn=978-0-12-352651-9}}</ref>{{rp|768}} Bismuth expands 3.32% on solidification, so it was long a component of low-melting typesetting alloys, where it compensated for the contraction of the other alloying components<ref name="CRC" /><ref>{{cite book| url =https://books.google.com/books?id=XD-dhveegRYC| page = 268| title =Modern physical science| isbn =978-0-03-007381-6| last1 =Tracy| first1 =George R.| last2 =Tropp| first2 =Harry E.| last3 =Friedl| first3 =Alfred E.| date =1974| publisher = Holt, Rinehart and Winston}}</ref><ref>{{cite journal| doi = 10.1039/JS8682100071| title = IX.—Freezing of water and bismuth| date = 1868| last1 = Tribe| first1 = Alfred| journal = Journal of the Chemical Society| volume = 21| page = 71| url = https://zenodo.org/record/2000757}}</ref><ref>{{cite book| url =https://books.google.com/books?id=n-fiyYg3iSIC&pg=PA82|page = 82| title =The Physics of Phase Transitions| isbn =978-3-540-33390-6| last1 =Papon| first1 =Pierre| last2 =Leblond| first2 =Jacques| last3 =Meijer| first3 =Paul Herman Ernst| date =2006| publisher=Springer }}</ref> 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 {{convert|271|C|F}}, so crystals may be grown using a household stove, although the resulting crystals tend to be of lower quality than laboratory-grown crystals.<ref>{{cite book|url=https://books.google.com/books?id=FGaIhhZ8ivsC&pg=PA2|page=2|title=The science of crystallization: microscopic interfacial phenomena|last=Tiller| first = William A.|publisher=Cambridge University Press|date=1991|isbn=978-0-521-38827-6}}</ref>

At ambient conditions, bismuth shares the same layered structure as the metallic forms of arsenic and antimony,<ref name="Wiberg"/>{{rp|767}} crystallizing in the rhombohedral lattice.<ref name="Ullmanns"/>{{rp|172}} 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, so are used for calibration of high-pressure equipment.<ref>{{cite book|author=Boldyreva, Elena |author-link1=Elena Boldyreva |title=High-Pressure Crystallography: From Fundamental Phenomena to Technological Applications|url=https://books.google.com/books?id=pyN0dhHChzsC&pg=PA264|date=2010| publisher= Springer| isbn=978-90-481-9257-1|pages=264–265}}</ref><ref>{{cite book|last=Manghnani | first= Murli H.|title=Science and Technology of High Pressure: Proceedings of the International Conference on High Pressure Science and Technology (AIRAPT-17) |location=Honolulu, Hawaii |date=25–30 July 1999|volume=2|url=https://books.google.com/books?id=7OoZ9TN8ROQC&pg=PA1086|publication-date=2000|publisher=Universities Press (India) | isbn=978-81-7371-339-2|page=1086}}</ref>

=== Chemical characteristics === Bismuth is stable to both dry and moist air at ordinary temperatures. At sufficiently high temperatures, it can react with water vapor to make bismuth(III) oxide.<ref name="Suzuki">{{cite book|ref=Suzuki|author=Suzuki, Hitomi |title=Organobismuth Chemistry|url=https://books.google.com/books?id=qODswAbaBmsC&pg=PA8|date=2001|publisher=Elsevier|isbn=978-0-444-20528-5|pages=1–20}}</ref>{{rp|8}}

: {{chem2|2 Bi + 3 H2O -> Bi2O3 + 3 H2}}

It reacts with fluorine to form bismuth(V) fluoride at {{convert|500|C|F}} or bismuth(III) fluoride at lower temperatures (typically from Bi melts); with other halogens it yields only bismuth(III) halides.<ref name="Wiberg"/>{{rp|769–70}}<ref name="Greenwood">{{Greenwood&Earnshaw2nd |pages=553,559-61,578}}</ref>{{rp|559–61}}<ref name="Ullmanns"/>{{rp|185}} The trihalides are corrosive and easily react with moisture, forming oxyhalides with the formula BiOX.<ref name="Suzuki"/>{{rp|9}}

: {{chem2|2 Bi + 3 X2 -> 2 BiX3}} (X = F, Cl, Br, I) : {{chem2|BiX3 + H2O -> BiOX + 2 HX}}

Bismuth dissolves in concentrated sulfuric acid to make bismuth(III) sulfate and sulfur dioxide.<ref name="Suzuki"/>{{rp|8}}

: {{chem2|6 H2SO4 + 2 Bi -> 6 H2O + Bi2(SO4)3 + 3 SO2}}

It reacts with nitric acid to make bismuth(III) nitrate (which decomposes into nitrogen dioxide when heated<ref name = "Ollevier">{{cite book |last1=Krabbe |first1=S.W. |last2=Mohan |first2=R.S. |editor-first=Thierry |editor-last=Ollevier |title=Topics in Current chemistry 311, Bismuth-Mediated Organic Reactions |publisher=Springer |year=2012 |pages=100–110 |chapter=Environmentally friendly organic synthesis using Bi(III) compounds |isbn=978-3-642-27239-4}}</ref>).<ref>{{cite book |last=Rich |first=Ronald |date=2007 |title=Inorganic Reactions in Water (e-book) |publisher= Springer |isbn=978-3-540-73962-3 }}</ref>

: {{chem2|Bi + 6 HNO3 -> 3 H2O + 3 NO2 + Bi(NO3)3}}

It also dissolves in hydrochloric acid, but only with oxygen present.<ref name="Suzuki"/>{{rp|8}}

: {{chem2|4 Bi + 3 O2 + 12 HCl -> 4 BiCl3 + 6 H2O}}

=== Isotopes === {{Main|Isotopes of bismuth}} The only primordial isotope of bismuth, bismuth-209, had long been regarded as the heaviest stable nuclide, but was suspected<ref>{{cite journal |doi = 10.1007/BF02824346 |title = Alpha-activity of {{sup|209}}Bi |date = 1972 |last1 = Carvalho |first1 = H. G. |last2 = Penna |first2 = M. |journal = Lettere al Nuovo Cimento |volume = 3 |issue = 18|page = 720|s2cid = 120952231 }}</ref> on theoretical grounds to be unstable to alpha decay. This was finally demonstrated in 2003, when researchers at the {{interlanguage link|Institut d'astrophysique spatiale|fr}} in Orsay, France, detected this decay; the best value of the half-life is now {{val|2.01|e=19|u=years}} (3 Bq/t),<ref>{{cite journal |last = Marcillac |first = Pierre de |author2 = Noël Coron |author3 = Gérard Dambier |author4 = Jacques Leblanc |author5 = Jean-Pierre Moalic |name-list-style = amp |date=2003 |title = Experimental detection of α-particles from the radioactive decay of natural bismuth |journal = Nature |volume = 422 |pages = 876–878 |pmid=12712201 |doi = 10.1038/nature01541 |issue = 6934 |bibcode= 2003Natur.422..876D|s2cid = 4415582 }}</ref>{{NUBASE2016|ref}} over {{val||e=9}} times longer than the estimated age of the universe.<ref name="Kean" /> Due to its hugely long half-life, for all known medical and industrial applications, bismuth can be treated as stable. 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.<ref name="Kean" /> Bismuth has the longest known α-decay half-life, though tellurium-128 has the longest known by any mode: double beta decay at about {{val|2.25|e=24|u=years}}.{{NUBASE2020|ref}}

Six isotopes of bismuth with short half-lives (210–215 inclusive, but not 210m) occur in the natural radioactive decay chains of actinium, radium, thorium, and neptunium, and more have been synthesized. (Though all primordial {{sup|237}}Np has long since decayed, it is continually regenerated by (n,2n) knockout reactions on natural {{sup|238}}U.)<ref>{{cite book |url=https://books.google.com/books?id=ZAHJkrJlwbYC&pg=PA78|page =78 |title=Modern Nuclear Chemistry |isbn=978-0-471-11532-8 |last1= Loveland |first1=Walter D. |last2=Morrissey |first2=David J. |last3=Seaborg |first3=Glenn T. |date=2006|publisher =John Wiley & Sons |bibcode =2005mnc..book.....L }}</ref><ref>{{cite journal |last1=Peppard |first1=D. F. |last2=Mason |first2=G. W. |last3=Gray |first3=P. R. |last4=Mech |first4=J. F. |title=Occurrence of the (4n + 1) series in nature |journal=Journal of the American Chemical Society |date=1952 |volume=74 |issue=23 |pages=6081–6084 |doi=10.1021/ja01143a074 |bibcode=1952JAChS..74.6081P |url=https://digital.library.unt.edu/ark:/67531/metadc172698/m2/1/high_res_d/metadc172698.pdf }}</ref>

For medical use, bismuth-213 can be produced, as the parent isotope actinium-225, by bombarding radium with bremsstrahlung photons from a linear particle accelerator. In 1997, an antibody conjugate with bismuth-213 (half-life 45.6 minutes, emits alpha particles) was used to treat leukemia patients, and it has been used in other cancer treatment, for example, in the targeted alpha therapy <!-- (TAT) --> experimental program.<ref>{{cite journal|doi=10.1016/S0360-3016(01)01585-1| pmid=11516878| title=Advancements in cancer therapy with alpha-emitters: a review|date=2001| last1=Imam|first1=S.| journal=International Journal of Radiation Oncology, Biology, Physics|volume=51| issue=1| pages=271–8}}</ref><ref>{{cite book |url=https://books.google.com/books?id=Y6haWM6lFkYC&pg=PT520|page =520 |title=Issues in Cancer Epidemiology and Research |date= 2011 |isbn=978-1-4649-6352-0 |last= Acton | first= Ashton|publisher =ScholarlyEditions }}</ref>

== Chemical compounds == {{Main|Bismuth compounds}} [[File:Bismuth(III)_oxide_2.jpg|thumb|right|Bismuth(III) oxide powder]]

Chemically, bismuth resembles arsenic and antimony, but is much less toxic.<ref name=tox>{{cite book|chapter=Coordination Chemistry of the s, p, and f Metals|author1=Levason, W. |author2=Reid, G. |title= Comprehensive Coordination Chemistry II|year= 2003|doi=10.1016/B0-08-043748-6/02023-5| publisher=Elsevier Pergamon | place=Amsterdam | isbn=0-08-043748-6}}</ref> In almost all known compounds, bismuth has oxidation state +3; a few have states +5 or −3.

The trioxide<ref name="Wiberg"/>{{rp|768}}<ref name="Greenwood"/>{{rp|553}} and trisulfide can both be made from the elements,<ref name=Forgot>{{cite book|title=An Introduction to the Study of Chemistry|url=https://books.google.com/books?id=lGjTyw9gYfYC|publisher=Forgotten Books|isbn=978-1-4400-5235-4|page=363}}</ref><ref name="Greenwood"/>{{rp|559–61}} although the trioxide is extremely corrosive at high temperatures.<ref name="Ullmanns"/>{{rp|185}} The pentoxide is not stable at room temperature, and evolves {{chem2|O2}} gas if heated.<ref>{{cite book| title = Concise encyclopedia chemistry| url = https://archive.org/details/conciseencyclope0000unse_x5a9| url-access = registration| first1 = Thomas|last1 = Scott| first2 = Mary|last2 = Eagleson| publisher = Walter de Gruyter| date = 1994| isbn = 978-3-11-011451-5 | page = [https://archive.org/details/conciseencyclope0000unse_x5a9/page/136/ 136]}}</ref> Both oxides form complex anions,<ref name="norman1" /> and NaBiO<sub>3</sub> is a strong oxidising agent.<ref name="Greenwood"/>{{rp|578}} The trisulfide is common in bismuth ore.<ref name=Forgot />

Similarly, bismuth forms all possible trihalides, but the only pentahalide is {{chem2|BiF5}}. All are Lewis acids.<ref name="Suzuki"/>{{rp|8}} Bismuth forms several formally {{chem2|Bi^{I} }} halides; these are complex salts with unusually structured polyatomic cations and anions.<ref name="norman1" /><ref name="gillespie1">{{cite book| title = Advances in Inorganic Chemistry and Radiochemistry| url = https://archive.org/details/isbn_0120236176/page/n87 | url-access = limited| first1 = R. J. |last1 = Gillespie| first2 = J. |last2 = Passmore| editor = Emeléus, H. J.| editor2 = Sharp A. G.| publisher = Academic Press| date = 1975| isbn = 978-0-12-023617-6| pages = 77–78}}</ref>

[[File:MatlockiteStructure.png|thumb|upright|Bismuth oxychloride (BiOCl) structure (mineral bismoclite): Bismuth atoms are shown as grey, oxygen is red, and chlorine is green.]] In strongly acidic aqueous solution, the {{chem2|Bi(3+)}} ion solvates to form {{chem2|Bi(H2O)8(3+)}}.<ref name="Persson2010">{{cite journal|last1=Persson|first1=Ingmar|title=Hydrated metal ions in aqueous solution: How regular are their structures?|journal=Pure and Applied Chemistry|volume=82|issue=10|date=2010|pages=1901–1917|doi=10.1351/PAC-CON-09-10-22|doi-access=free}}</ref> As pH increases, the cations polymerize until the octahedral bismuthyl complex {{chem2|[Bi6O4(OH)4](6+)}},<ref name="NäslundPersson2000">{{cite journal|last1=Näslund|first1=Jan|last2=Persson|first2=Ingmar|last3=Sandström|first3=Magnus|title=Solvation of the Bismuth(III) Ion by Water, Dimethyl Sulfoxide, N,N'-Dimethylpropyleneurea, and N,N-Dimethylthioformamide. An EXAFS, Large-Angle X-ray Scattering, and Crystallographic Structural Study|journal=Inorganic Chemistry|volume=39|issue=18|date=2000|pages=4012–4021|doi=10.1021/ic000022m|pmid=11198855}}</ref> often abbreviated {{chem2|BiO+}}. Although bismuth oxychloride and bismuth oxynitrate have stoichiometries suggesting the ion, they are double salts instead.<ref name="Ullmanns"/>{{rp|184}} Bismuth nitrate hydrolysys in water, forming oxynitrate.

Bismuth forms very few stable bismuthides, intermetallic compounds in which it attains oxidation state −3.<ref>{{Cite journal |last=Okamoto |first=H. |date=2002-03-01 |title=Bi-Nd (Bismuth-Neodymium) |journal=Journal of Phase Equilibria |volume=23 |issue=2 |pages=191 |doi=10.1361/1054971023604224 }}</ref> The hydride spontaneously decomposes at room temperature and stabilizes only below {{convert|−60|C|F}}.<ref name="norman1">{{cite book | title = Chemistry of arsenic, antimony, and bismuth | first1 = S. M. |last1 =Godfrey | first2 = C. A. |last2 =McAuliffe | first3 = A. G. |last3 =Mackie | first4 = R. G. |last4 =Pritchard | editor-first = Nicholas C. |editor-last =Norman | publisher = Springer | date = 1998 | isbn = 978-0-7514-0389-3 | pages = 67–84 }}</ref> Sodium bismuthide has interest as a topological Dirac insulator.<ref name="k1401">{{cite web |url=https://www.kurzweilai.net/3d-counterpart-to-graphene-discovered |title=3D counterpart to graphene discovered [UPDATE] |date=20 January 2014|publisher=KurzweilAI |access-date=28 January 2014}}</ref><ref>{{Cite journal | last1 = Liu | first1 = Z. K. | last2 = Zhou | first2 = B. | last3 = Zhang | first3 = Y. | last4 = Wang | first4 = Z. J. | last5 = Weng | first5 = H. M. | last6 = Prabhakaran | first6 = D. | last7 = Mo | first7 = S. K. | last8 = Shen | first8 = Z. X. | last9 = Fang | first9 = Z. | last10 = Dai | first10 = X. | last11 = Hussain | first11 = Z. | last12 = Chen | first12 = Y. L. | title = Discovery of a Three-Dimensional Topological Dirac Semimetal, Na<sub>3</sub>Bi | doi = 10.1126/science.1245085 | journal = Science | year = 2014 |arxiv=1310.0391| pmid = 24436183| volume=343 | issue = 6173 | pages=864–7|bibcode = 2014Sci...343..864L | s2cid = 206552029 }}</ref>

== Occurrence and production ==

=== Production === [[File:Bismite.jpg|thumb|upright|Bismite mineral]] thumb|upright|Chunk of a broken bismuth ingot

The reported abundance of bismuth in the Earth's crust varies significantly by source from 180 ppb (similar to that of silver) to 8 ppb (twice as common as gold). The most important ores of bismuth are bismuthinite and bismite.<ref name="CRC" /> Native bismuth is known from Australia, Bolivia, and China.<ref name="arizona1">{{cite book|editor=Anthony, John W.|editor2=Bideaux, Richard A.|editor3=Bladh, Kenneth W.|editor4=Nichols, Monte C. |title=Handbook of Mineralogy: Elements, Sulfides, Sulfosalts |date=15 April 1990 |publisher=Mineralogical Society of America |place=Chantilly, VA, US |chapter-url=http://rruff.geo.arizona.edu/doclib/hom/bismuth.pdf |section=Bismuth |access-date=5 December 2011 |isbn=978-0-9622097-0-3}}</ref><ref name="Ullmanns"/>{{rp|172–3}}

{{srn}}{{table alignment}} {| class="wikitable sortable static-row-numbers col1left" {{right}} |+World bismuth production<ref>{{Cite web |title=Mineral Commodity Summaries 2025 - Bismuth |url=https://pubs.usgs.gov/periodicals/mcs2025/mcs2025-bismuth.pdf |archive-date= |access-date=2025-09-16}}</ref><ref>{{Cite web |title=World mineral statistics data |url=https://www.bgs.ac.uk/mineralsuk/statistics/world-mineral-statistics/world-mineral-statistics-data-download/world-mineral-statistics-data/ |access-date=2025-09-16 |website=MineralsUK |language=en-GB}}</ref> !Country!!Production<br>(metric tonnes) !Year |- |{{Noflag}}'''World'''||'''16,000'''||'''2024''' |- |{{Flag|China}}||13,000||2024 |- |{{Flag|Vietnam}}||1,938||2022 |- |{{Flag|Laos}}||1,100||2024 |- |{{Flag|South Korea}}||1,000||2024 |- |{{Flag|Japan}}||500||2024 |- |{{Flag|Peru}}||251||2022 |- |{{Flag|Kazakhstan}}||180||2024 |- |{{Flag|Bolivia}}||70||2024 |- |{{Flag|Bulgaria}}||50||2024 |- |{{Flag|Russia}}||45||2022 |- |{{Flag|Armenia}}||4||2022 |}

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.<ref name="Ullmanns"/>{{rp|173}}<ref name="Oje" /><ref>{{cite journal |doi = 10.1016/0891-3919(57)90180-8 |title = The preparation of bismuth for use in a liquid-metal fuelled reactor |date = 1957 |last1 = Horsley |first1 = G. W. |journal = Journal of Nuclear Energy |volume = 6 |issue = 1–2 |page = 41}}</ref><ref>{{cite journal |doi = 10.1134/S0020168511020166 |title = Pb distribution in multistep bismuth refining products |date = 2011 |last1 = Shevtsov |first1 = Yu. V. |last2 = Beizel’ |first2 = N. F. |journal = Inorganic Materials |volume = 47 |issue = 2 |page = 139|s2cid = 96931735 }}</ref>

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 behaves similarly with another of its major metals, copper.<ref name="Oje">{{cite journal |doi = 10.1007/BF03222821 |title = Bismuth—Production, properties, and applications |date = 1992 |last1 = Ojebuoboh |first1 = Funsho K. |journal = JOM |volume = 44 |issue = 4 |pages = 46–49|bibcode = 1992JOM....44d..46O|s2cid = 52993615 }}</ref> 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).<ref name=usgs2/>

=== Price === thumb|upright=1.3|World mine production and annual averages of bismuth price (New York, not adjusted for inflation).<ref name="usgs" /> The price for pure bismuth metal was 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, thus the price usually reflected the cost of recovery and the balance between production and demand.<ref name="usgs" />

Before 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.<ref name="usgs" />

In the early 1970s, the price rose rapidly due to 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.<ref name="Suzuki"/>{{rp|14}} 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.<ref name="usgs">[https://minerals.usgs.gov/minerals/pubs/commodity/bismuth/ Bismuth Statistics and Information]. see "Metal Prices in the United States through 1998" for a price summary and "Historical Statistics for Mineral and Material Commodities in the United States" for production. USGS.</ref>

=== Recycling === Most bismuth is produced as a byproduct of other metal-extraction processes, including the smelting of lead, tungsten, and copper. Its sustainability is dependent on increased recycling, which is problematic.<ref>{{cite report |first1=M. |last1=Gislev |first2=M. |last2=Grohol |first3=F. |last3=Mathieux |first4=F. |last4=Ardente |first5=S. |last5=Bobba |first6=P. |last6=Nuss |first7=G.A. |last7=Blengini |first8=P.A. |last8=Dias |first9=D. |last9=Blagoeva |first10=C. |last10=Torres de Matos |first11=D. |last11=Wittmer |first12=C. |last12=Pavel |first13=T. |last13=Hamor |first14=H. |last14=Saveyn |first15=B. |last15=Gawlik |first16=G. |last16=Orveillon |first17=D. |last17=Huygens |first18=E. |last18=Garbarino |first19=E. |last19=Tzimas |first20=F. |last20=Buraoui |first21=S. |last21=Solar |title=Report on critical raw materials and the circular economy |date=2018-11-05 |location=Luxembourg |publisher=Publications Office of the European Union |url=https://weee4future.eitrawmaterials.eu/wp-content/uploads/2020/09/09_report-of-CRM-and-CE.pdf |doi=10.2873/167813 |isbn=978-92-79-94626-4 }}{{page needed|date=July 2025}}</ref>

Bismuth was once believed to be practically recycled from the soldered joints in electronic equipment. Recent efficiencies in solder application in electronics mean substantially less solder is deposited, thus less is available to recycle. While recovering the silver from silver-bearing solder may remain economic, recovering bismuth is substantially less so.<ref>{{cite web|url = http://leadfree.ipc.org/files/RoHS_15.pdf|author = Warburg, N|publisher = University of Stuttgart|title = IKP, Department of Life-Cycle Engineering|access-date = 5 May 2009|url-status = dead|archive-url = https://web.archive.org/web/20090225155540/http://leadfree.ipc.org/files/RoHS_15.pdf|archive-date = 25 February 2009|df = dmy-all}}</ref>

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.<ref name=usgs2/>

== Applications == alt=Black and white engraving of two men extracting and working bismuth, hammering and pouring on a hillside|thumb|upright|An 18th-century engraving of bismuth processing: During this era, bismuth was used to treat some digestive complaints. Bismuth has few commercial applications, and those 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.<ref name=usgs2>{{cite web|url=https://pubs.usgs.gov/myb/vol1/2018/myb1-2018-bismuth.pdf|title=2018 USGS Minerals Yearbook: Bismuth|publisher = United States Geological Survey| author1=Singerling, Sheryl A. |author2=Callaghan, Robert M. }}</ref> <!-- already mentioned twice In the early 1990s, researchers began to evaluate bismuth as a nontoxic replacement for lead in various applications.<ref name=usgs2/> -->

=== Medicines ===

Bismuth is an ingredient in some pharmaceuticals,<ref name="Kean" /> although the use of some of these substances is declining.<ref name="Ullmanns"/>{{rp|184}} * Bismuth subsalicylate is used to treat diarrhea;<ref name="Kean" /> it is the active ingredient in such "pink bismuth" preparations as Pepto-Bismol, as well as the 2004 reformulation of Kaopectate. It is also used to treat some other gastrointestinal diseases such as shigellosis<ref>[https://www.cdc.gov/shigella/diagnosistreatment.html CDC, shigellosis].</ref> and cadmium poisoning.<ref name="Kean" /> The mechanism of action of this substance is still not well documented, although an oligodynamic effect (toxic effect of small doses of heavy metal ions on microbes) may be involved in at least some cases. Salicylic acid from hydrolysis of the compound is antimicrobial for toxogenic ''E. coli,'' an important pathogen in traveler's diarrhea.<ref>{{cite journal|author=Sox TE|author2= Olson CA|title=Binding and killing of bacteria by bismuth subsalicylate|journal =Antimicrob Agents Chemother|date= 1989|volume=33|issue=12|pages=2075–82|pmid=2694949|pmc=172824|doi=10.1128/AAC.33.12.2075}}</ref> * A combination of bismuth subsalicylate and bismuth subcitrate is used to treat the bacteria causing peptic ulcers.<ref>{{cite web|url=http://www.ema.europa.eu/docs/en_GB/document_library/PIP_decision/WC500005327.pdf|title=P/74/2009: European Medicines Agency decision of 20 April 2009 on the granting of a product specific waiver for Bismuth subcitrate potassium / Metronidazole / Tetracycline hydrochloride (EMEA-000382-PIP01-08) in accordance with Regulation (EC) No 1901/2006 of the European Parliament and of the Council as amended|publisher=European Medicines Agency|date=2009-06-10|access-date=13 August 2022|archive-date=24 October 2017|archive-url=https://web.archive.org/web/20171024205050/http://www.ema.europa.eu/docs/en_GB/document_library/PIP_decision/WC500005327.pdf|url-status=dead}}</ref><ref>{{cite journal | vauthors = Urgesi R, Cianci R, Riccioni ME | title = Update on triple therapy for eradication of Helicobacter pylori: current status of the art | journal = Clinical and Experimental Gastroenterology | volume = 5 | pages = 151–7 | year = 2012 | pmid = 23028235 | pmc = 3449761 | doi = 10.2147/CEG.S25416 | doi-access = free }}</ref> * Bibrocathol is an organic bismuth-containing compound used to treat eye infections.<ref>{{cite book | vauthors = Gurtler L | chapter = Chapter 2: The Eye and Conjunctiva as Target of Entry for Infectious Agents: Prevention by Protection and by Antiseptic Prophylaxis | veditors = Kramer A, Behrens-Baumann W |title=Antiseptic prophylaxis and therapy in ocular infections: principles, clinical practice, and infection control | series = Developments in Ophthalmology |date= January 2002 | volume = 33 | pages = 9–13 |publisher=Karger |location=Basel |isbn=978-3-8055-7316-0 | doi = 10.1159/000065934 | pmid = 12236131 | chapter-url = https://books.google.com/books?id=JkQOSAnOIhoC&dq=Bibrocathol&pg=PA96 }}</ref> * Bismuth subgallate, the active ingredient in Devrom, is used as an internal deodorant to treat malodor from flatulence and feces.<ref>{{cite journal | vauthors = Gorbach SL | title = Bismuth therapy in gastrointestinal diseases | journal = Gastroenterology | volume = 99 | issue = 3 | pages = 863–75 | date = September 1990 | pmid = 2199292 | doi = 10.1016/0016-5085(90)90983-8 | author-link = Sherwood Gorbach }}</ref><ref>{{cite journal | vauthors = Sparberg M | title = Correspondence: Bismuth subgallate as an effective means for the control of ileostomy odor: a double blind study | journal = Gastroenterology | volume = 66 | issue = 3 | pages = 476 | date = March 1974 | pmid = 4813513 | doi = 10.1016/S0016-5085(74)80150-2 | doi-access = free }}</ref> * Bismuth salts began being used for treatment of congenital syphilis in 1884,<ref name="Lewis 2018">{{cite book |vauthors=Lewis M |title=Paleopathology of Children |chapter=Miscellaneous Conditions |publisher=Elsevier |date=2018 |isbn=978-0-12-410402-0 |doi=10.1016/b978-0-12-410402-0.00011-4 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780124104020000114 |access-date=7 February 2026 |page=267–281}}</ref> expanding to syphilis treatment in the general population between 1921 and 1924. Bismuth salts (including sodium bismuth tartrate) administered via intramuscular injection offered a less toxic alternative or supplement to arsenic-based therapies such as Salvarsan. Bismuth compounds served as a standard treatment for syphilis until 1943, when the introduction of penicillin superseded heavy metal-based protocols.<ref name="pmid24335464">{{cite journal |vauthors=Karamanou M, Kyriakis K, Tsoucalas G, Androutsos G |title=Hallmarks in history of syphilis therapeutics |journal=Le Infezioni in Medicina |volume=21 |issue=4 |pages=317–9 |date=December 2013 |pmid=24335464 |url=https://www.infezmed.it/media/journal/Vol_21_4_2013_10.pdf}}</ref><ref name="pmid873671">{{cite journal |vauthors=Degos R |title=Bismuth in the treatment of syphilis |journal=International Journal of Dermatology |volume=16 |issue=5 |pages=391–2 |date=June 1977 |pmid=873671 |doi=10.1111/j.1365-4362.1977.tb00761.x}}</ref><ref>{{cite journal|author=Parnell, R. J. G. |title=Bismuth in the Treatment of Syphilis|journal=Journal of the Royal Society of Medicine|date=1924|volume=17|pages=19–26|pmc=2201253|issue=War section|pmid=19984212|doi=10.1177/003591572401702604}}</ref><ref>Giemsa, Gustav (1924) {{US patent|1540117}} "Manufacture of bismuth tartrates"</ref><ref>{{cite journal |last1=Frith |first1=John |title=Syphilis – Its Early History and Treatment Until Penicillin, and the Debate on its Origins |journal=Journal of Military and Veterans' Health |date=November 2012 |volume=20 |issue=4 |page=54 |url=https://jmvh.org/article/syphilis-its-early-history-and-treatment-until-penicillin-and-the-debate-on-its-origins/ |access-date=30 January 2022}}</ref> Despite this shift, bismuth therapies persisted in several regions, such as France, where they remained in use for specific stages of the disease until at least the late 1970s.<ref name="pmid873671"/> * "Milk of bismuth" (an aqueous suspension of bismuth hydroxide and bismuth subcarbonate) was marketed as an alimentary cure-all in the early 20th century, and has been used to treat gastrointestinal disorders.<ref>{{Cite web |url=http://www.medilexicon.com/medicaldictionary.php?t=55448 |title=Milk of Bismuth |access-date=2022-08-13 |archive-date=2013-06-04 |archive-url=https://web.archive.org/web/20130604170722/http://www.medilexicon.com/medicaldictionary.php?t=55448 |url-status=dead }}</ref> * Bismuth subnitrate ({{chem2|Bi5O(OH)9(NO3)4}}) and bismuth subcarbonate ({{chem2|Bi2O2(CO3)}}) are also used in medicine.<ref name="CRC" />

=== Cosmetics and pigments ===

Bismuth oxychloride (BiOCl) is sometimes used in cosmetics, as a pigment in paint for eye shadows, hair sprays, and nail polishes.<ref name="Kean" /><ref name="Ullmanns"/>{{rp|184}}<ref name="Effp">{{cite journal|doi = 10.1016/j.porgcoat.2005.07.003|title = Effect pigments—past, present and future|date = 2005|last1 = Maile|first1 = Frank J.|last2 = Pfaff|first2 = Gerhard|last3 = Reynders|first3 = Peter|journal = Progress in Organic Coatings|volume = 54|issue = 3|page = 150 | bibcode=2005POrCo..54..150M }}</ref><ref name="Paff">{{cite book|url = https://books.google.com/books?id=Q1Pc0aY-vg4C&pg=PA36| page = 36|title = Special effect pigments: Technical basics and applications|isbn = 978-3-86630-905-0|last1 = Pfaff|first1 = Gerhard|date = 2008|publisher=Vincentz Network GmbH}}</ref> 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 (BiONO<sub>3</sub>), when used as a white pigment.<ref>{{cite book |last=Sadler |first=Peter J|editor-first=A.G. |editor-last=Sykes |title=ADVANCES IN INORGANIC CHEMISTRY, Volume 36 |publisher=Academic Press |date=1991 |chapter=Chapter 1|isbn=0-12-023636-2}}</ref> Bismuth vanadate is used as a light-stable nonreactive 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.<ref>{{cite book | last=Weldon | first=Dwight G. | title=Failure analysis of paints and coatings | publisher=Wiley | publication-place=Chichester, U.K. | date=2009 | isbn=978-1-61583-267-5 | oclc=608477934 | page=40}}</ref>

=== Electronics ===

==== Transistors ==== Bismuth-based materials have been claimed to enable smaller, faster, and more energy-efficient transistors than traditional silicon. Bismuth offers a small bandgap and high electron mobility. It has topological insulator states, conducting along its surface/edges while still insulating internally. Two-dimensional semiconductor (2D) materials can be produced from it, enabling thinner and higher-performance devices. Such 2D bismuth materials support subnanometer channel lengths, surpassing silicon's practical limits. However, bismuth's anisotropic heat transport can complicate chip design.<ref>{{cite journal |last1=Shi |first1=Meng |last2=Yang |first2=Huiying |last3=Zhao |first3=Zehui |last4=Ren |first4=Guangmin |last5=Meng |first5=Xiangchao |title=Bismuth-based semiconductors applied in photocatalytic reduction processes: fundamentals, advances and future perspectives |journal=Chemical Communications |date=2023 |volume=59 |issue=29 |pages=4274–4287 |doi=10.1039/D3CC00580A |pmid=36942529 }}</ref>

Bismuth telluride ({{Chem2|Bi2Te3}}) has been investigated for use in thermoelectric transistors that use temperature gradients (e.g., via laser illumination) to generate electricity, yielding {{val|0.7093|u=μW}} in experimental setups. They operate by leveraging the Seebeck effect, using a temperature difference to drive charge carrier movement.<ref>{{Cite journal |last1=Deng |first1=Hao |last2=Nan |first2=Bohang |last3=Xu |first3=Guiying |date=January 2023 |title=Innovative Design of Bismuth-Telluride-Based Thermoelectric Transistors |journal=Materials |language=en |volume=16 |issue=16 |pages=5536 |doi=10.3390/ma16165536 |doi-access=free |pmid=37629826 |pmc=10456323 |bibcode=2023Mate...16.5536D |issn=1996-1944}}</ref>

Bismuth oxyselenides ({{Chem2|Bi2O2Se}} and {{Chem2|Bi2SeO5}}) have been investigated for use in field-effect transistors (FETs). These 2D materials exhibit high electron mobility (e.g., {{val|10|–|15|u=cm2/(V·s)}}) and stability in air. One study reported that these materials enabled transistors that were 40% faster and 10% more efficient than Intel's {{val|3|u=nm}} chips.<ref>{{Cite web |last=Sinha |first=Sujita |title=China's 'fastest-ever' 2D chip beats Intel with 40% more speed |url=https://interestingengineering.com/innovation/chinas-chip-runs-40-faster-without-silicon |access-date=2025-03-12 |website=Interesting Engineering |language=en}}</ref><ref>{{Cite book |last1=Feng |first1=Tingling |last2=Xie |first2=Dan |last3=Zang |first3=Yongyuan |last4=Wu |first4=Xaio |last5=Luo |first5=Yafeng |last6=Ren |first6=Tianling |last7=Bosund |first7=Markus |last8=Li |first8=Shuo |last9=Airaksinen |first9=Veli-Matti |last10=Lipsanen |first10=Harri |last11=Honkanen |first11=Seppo |chapter=Nd-doped Bismuth Titanate based ferroelectric field effect transistor: Design, fabrication, and optimization |date=November 2011 |title=2011 IEEE International Conference of Electron Devices and Solid-State Circuits |pages=1–2 |doi=10.1109/EDSSC.2011.6117648|isbn=978-1-4577-1998-1 }}</ref>

Bismuth can reduce contact resistance when paired with 2D semiconductors such as {{Chem2|MoS2}}. This eliminates the Schottky barrier—a common efficiency issue in metal-semiconductor interfaces.<ref>{{Cite web |last=Chandler |first=David L. |date=2021-05-13 |title=Advance may enable "2D" transistors for tinier microchip components |url=https://news.mit.edu/2021/2d-transistors-microchip-0513 |access-date=2025-03-12 |website=MIT News {{!}} Massachusetts Institute of Technology |language=en}}</ref>

=== Metal and alloys ===

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 during the Bronze Age, having been found in Inca knives at Machu Picchu.<ref>{{cite journal|jstor=1692247 |title=Bismuth Bronze from Machu Picchu, Peru |publisher=American Association for the Advancement of Science |last1=Gordon |first1=Robert B. |last2=Rutledge |first2=John W. |journal=Science |year=1984 |volume=223 |issue=4636 |pages=585–586 |doi=10.1126/science.223.4636.585 |pmid=17749940 |bibcode=1984Sci...223..585G |s2cid=206572055 }}</ref>

==== Lead replacement ==== The density difference between lead ({{val|11.32|u=g/cm3}}) and bismuth ({{val|9.78|u=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.<ref name=usgs2/>

Bismuth, as a dense element of high atomic weight, is used in bismuth-impregnated latex shields to shield from X-rays in medical examinations, such as CTs, mostly as it is considered nontoxic.<ref>{{cite journal|author=Hopper KD|author2=King SH|author3=Lobell ME|author4=TenHave TR|author5=Weaver JS|title= The breast: inplane x-ray protection during diagnostic thoracic CT—shielding with bismuth radioprotective garments|pmid=9393547|date=1997|volume=205|issue=3|pages=853–8|journal=Radiology|doi=10.1148/radiology.205.3.9393547}}</ref>

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.<ref name=usgs2 /> Its low toxicity is 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.<ref name="lohse">{{cite web|first1 = Joachim |last1 = Lohse|first2 = Stéphanie |last2 = Zangl|first3=Rita|last3=Groß|first4=Carl-Otto|last4=Gensch|first5=Otmar|last5=Deubzer|url = http://ec.europa.eu/environment/waste/pdf/description_layout.pdf| access-date =11 September 2009|title = Adaptation to Scientific and Technical Progress of Annex II Directive 2000/53/EC|publisher=European Commission|date=September 2007}}</ref>

Bismuth has been evaluated as a replacement for lead in free-machining brasses for plumbing applications,<ref>{{cite journal|doi = 10.1016/j.matchar.2006.02.005|title = Compositional distributions in classical and lead-free brasses|date = 2006|last1 = La Fontaine|first1 = A.|last2 = Keast|first2 = V. J.|journal = Materials Characterization|volume = 57|issue = 4–5|page = 424}}</ref> although it does not equal the performance of leaded steels.<ref name="lohse" />

==== Other metal uses and specialty alloys ====

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 {{chem2|In19.1\-Cd5.3\-Pb22.6\-Sn8.3\-Bi44.7}} alloy that melts at {{convert|47|C}}<ref name="CRC" /> 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 {{convert|70|C|F}}, 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.<ref name="Ullmanns"/>{{rp|183}}

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, so lead and bismuth are often used in similar quantities.<ref>{{cite book|url = https://books.google.com/books?id=Wl1azjcJblIC&pg=PA239|page = 239|title = Steels: Metallurgy and applications|isbn = 978-0-7506-3757-2|last1 = Llewellyn|first1 = D. T.|last2 = Hudd|first2 = Roger C.|date = 1998|publisher=Butterworth-Heinemann}}</ref><ref>{{cite book|url =https://books.google.com/books?id=Lskj5k3PSIcC&pg=PA41| page = 41|title =Aluminum and Aluminum Alloys|isbn =978-0-87170-496-2|last1 =Davis |first1 =J. R.|date =1993|publisher=ASM International}}</ref> 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.<ref name="Ullmanns"/>{{rp|183}} Bismuth is also used as an alloying agent in production of malleable irons<ref name=usgs2 /> and as a thermocouple material.<ref name="CRC" />

Bismuth is also used in aluminium-silicon cast alloys to refine silicon morphology. However, it indicated a poisoning effect on modification of strontium.<ref>{{cite journal|last=Farahany|first=Saeed|author2=A. Ourdjini|author3=M.H. Idris|author4=L.T. Thai|title=Poisoning effect of bismuth on modification behavior of strontium in LM25 alloy|journal=Journal of Bulletin of Materials Science|date=2011|volume=34|issue=6|pages=1223–1231|doi=10.1007/s12034-011-0239-5|doi-access=free}}</ref><ref>{{cite journal|last=Farahany|first=Saeed|author2=A. Ourdjini|author3=M. H. Idris|author4=L.T. Thai|title=Effect of bismuth on the microstructure of unmodified and Sr-modified Al-7%Si-0.4Mg alloy|journal=Journal of Transactions of Nonferrous Metals Society of China|date=2011|volume=21|issue=7|pages=1455–1464|doi=10.1016/S1003-6326(11)60881-9|s2cid=73719425 }}</ref> Some bismuth alloys, such as {{chem2|Bi35\-Pb37\-Sn25}}, are combined with nonsticking 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.<ref name="Ullmanns"/>{{rp|184}} Sintering of bismuth and manganese powders at {{convert|300|C|F}} produces a permanent magnet and magnetostrictive material, which is used in ultrasonic generators and receivers working in the {{val|10|–|100|u=kHz}} range and in magnetic and holographic memory devices.<ref name="Suzuki"/>{{rp|15}}

=== Other uses as compounds ===

[[File:Bismuthvanadat.jpg|thumb|Bismuth vanadate, a yellow pigment]] * Bismuth is included in bismuth strontium calcium copper oxide, which is a group of similar superconducting compounds discovered in 1988 that exhibit the highest superconducting transition temperatures.<ref>{{cite web|publisher = National High Magnetic Field Laboratory|title = BSCCO|url = http://www.magnet.fsu.edu/magnettechnology/research/asc/research/bscco.html|access-date = 18 January 2010|archive-url = https://web.archive.org/web/20130412234316/http://www.magnet.fsu.edu/magnettechnology/research/asc/research/bscco.html|archive-date = 12 April 2013|url-status = dead}}</ref><!-- 9780199565917Oxford University Press, 2009Laszlo Solymar, Donald WalshElectrical Properties of Materials https://books.google.com/books?id=AiWyp0NQW6UC&pg=PA389 --> * Bismuth telluride is a semiconductor and an excellent thermoelectric material.<ref name="Ullmanns"/>{{rp|184}}<ref>{{cite book |url = https://books.google.com/books?id=jO3nzAbzAWYC&pg=PA12|page = 12 |title = Recent trends in thermoelectric materials research |isbn = 978-0-12-752178-7 |last1 = Tritt |first1 = Terry M. |date = 2000|publisher=Academic Press}}</ref> {{chem2|Bi2Te3}} diodes are used in mobile refrigerators, CPU coolers, and as detectors in infrared spectrophotometers.<ref name="Ullmanns"/>{{rp|184}} * Bismuth oxide, in its delta form, is a solid electrolyte for oxygen. This form normally breaks down below a high-temperature threshold, but can be electrodeposited well below this temperature in a highly alkaline solution.<ref>{{cite book |last1=Maric |first1=Radenka |last2=Mirshekari |first2=Gholamreza |title=Solid oxide fuel cells : from fundamental principles to complete systems |publisher=CRC Press |publication-place=Boca Raton |date=2020 |isbn=978-0-429-52784-5 |oclc=1228350036 |page=70}}</ref> * Bismuth germanate is a scintillator, widely used in X-ray and gamma ray detectors.<ref>{{cite book | last=Saha | first=Gopal B. | title=Physics and radiobiology of nuclear medicine | publisher=Springer | publication-place=New York | date=2006 | isbn=978-0-387-36281-6 | oclc=655784658 | page=82}}</ref> * Bismuth vanadate is an opaque yellow pigment used by some artists' oil, acrylic, and watercolor paint companies, primarily as a replacement for the more toxic cadmium sulfide yellows in the greenish-yellow (lemon) to orange-toned yellow range. It performs practically identically to the cadmium pigments, such as in terms of resistance to degradation from UV exposure, opacity, tinting strength, and lack of reactivity when mixed with other pigments. The most commonly used variety by artists' paint makers is lemon in color. In addition to being a replacement for several cadmium yellows, it also serves as a nontoxic visual replacement for the older chromate pigments made with zinc, lead, and strontium. If a green pigment and barium sulfate (for increased transparency) are added, it can also serve as a replacement for barium chromate, which possesses a more greenish cast than the others. In comparison with lead chromate, it does not blacken due to hydrogen sulfide in the air (a process accelerated by UV exposure) and possesses a particularly brighter color than them, especially the lemon, which is the most translucent, dull, and fastest to blacken due to the higher percentage of lead sulfate required to produce that shade. It is also used, on a limited basis due to its cost, as a vehicle paint pigment.<ref>{{cite journal|doi = 10.1016/j.dyepig.2005.08.027|title = The photochromic effect of bismuth vanadate pigments: Investigations on the photochromic mechanism|date = 2007|last1 = Tücks|first1 = Andreas|last2 = Beck|first2 = Horst P.|journal = Dyes and Pigments|volume = 72|issue = 2|page = 163}}</ref><ref>{{cite book|chapter-url = https://books.google.com/books?id=WZV_hX9u0yIC&pg=PA92|chapter = Yellow pigments|pages = 91–93|title = Coloring of plastics: Fundamentals, colorants, preparations|isbn = 978-1-56990-352-0|author = Müller, Albrecht|publisher=Hanser Verlag|date = 2003}}</ref> Bismuth vanadate can also be used as electrocatalyst for hydrogen peroxide synthesis.<ref>{{cite journal |last1=Perry |first1=Samuel C. |last2=Pangotra |first2=Dhananjai |last3=Vieira |first3=Luciana |last4=Csepei |first4=Lénárd-István |last5=Sieber |first5=Volker |last6=Wang |first6=Ling |last7=Ponce de León |first7=Carlos |last8=Walsh |first8=Frank C. |title=Electrochemical synthesis of hydrogen peroxide from water and oxygen |journal=Nature Reviews Chemistry |date=19 June 2019 |volume=3 |issue=7 |pages=442–458 |doi=10.1038/s41570-019-0110-6 }}</ref> * Bismuth tungstate can be used as photocatalyst for removal of phenolic compounds<ref>{{cite journal |last1=Arora |first1=Isha |last2=Garg |first2=Seema |last3=Chawla |first3=Harshita |last4=Sapi |first4=Andras |last5=Ingole |first5=Pravin Popinand |last6=Sagadeven |first6=Suresh |last7=Khan |first7=Azmat Ali |last8=Fatima |first8=Sabiha |last9=Chandra |first9=Amrish |title=Visible-light-active 'bismuth tungstate/curcuma longa' z-scheme heterostructured photocatalyst for the degradation of methyl orange and phenol |journal=Reaction Kinetics, Mechanisms and Catalysis |date=June 2025 |volume=138 |issue=3 |pages=1797–1811 |doi=10.1007/s11144-025-02796-1 }}</ref> as well as for hydrogen generation.<ref>{{cite journal |last1=Ahmad |first1=Khursheed |last2=Nde |first2=Dieudonne Tanue |last3=Khan |first3=Rais Ahmad |title=Hydrothermal synthesis of bismuth-doped tungsten trioxide (Bi-WO3) for photocatalytic hydrogen production application |journal=Reaction Kinetics, Mechanisms and Catalysis |date=December 2024 |volume=137 |issue=6 |pages=3487–3498 |doi=10.1007/s11144-024-02679-x }}</ref> * Bismuth molybdate is a catalyst for propylene oxidation<ref>Kinetic studies of propane oxidation on Mo and V based mixed oxide catalysts, 2011, <nowiki>https://pure.mpg.de/rest/items/item_1199619_5/component/file_1199618/content</nowiki></ref> as well as photocatalyst.<ref>{{cite journal |last1=Ajiboye |first1=Timothy O. |last2=Oyewo |first2=Opeyemi A. |last3=Onwudiwe |first3=Damian C. |title=The performance of bismuth-based compounds in photocatalytic applications |journal=Surfaces and Interfaces |date=April 2021 |volume=23 |article-number=100927 |doi=10.1016/j.surfin.2021.100927 }}</ref> * A catalyst for making acrylic fibers.<ref name="CRC" /> * As an electrocatalyst in the conversion of {{chem2|CO2}} to CO.<ref>{{Cite journal|title=Selective conversion of CO<sub>2</sub> to CO with high efficiency using an bismuth-based electrocatalyst|author=DiMeglio, John L.|author2=Rosenthal, Joel |date=2013 |journal=Journal of the American Chemical Society|volume=135 |issue=24 |pages=8798–8801|doi=10.1021/ja4033549|pmid=23735115|pmc=3725765}}</ref> * Ingredient in lubricating greases.<ref>{{cite book |url =https://books.google.com/books?id=YTa5TsL0KnIC&pg=PA430|page = 430 |title =Chemistry and Technology of Lubricants |isbn =978-1-4020-8661-8 |last1 =Mortier |first1 =Roy M. |last2 =Fox |first2 =Malcolm F. |last3 =Orszulik |first3 =Stefan T. |date =2010|publisher=Springer|bibcode = 2010ctl..book.....M }}</ref> * In crackling microstars (dragon's eggs) in pyrotechnics, as the oxide, subcarbonate or subnitrate.<ref>{{cite journal|doi = 10.1016/j.atmosenv.2010.05.048|title = Emission factors and exposures from ground-level pyrotechnics|date = 2010|last1 = Croteau|first1 = Gerry|last2 = Dills|first2 = Russell|last3 = Beaudreau|first3 = Marc|last4 = Davis|first4 = Mac|journal = Atmospheric Environment|volume = 44|issue = 27|page = 3295|bibcode = 2010AtmEn..44.3295C }}</ref><ref>{{cite book|url = https://books.google.com/books?id=370UwG8CuNwC&pg=PA518|title = The Preparatory Manual of Black Powder and Pyrotechnics|isbn = 978-1-4116-8574-1|last1 = Ledgard|first1 = Jared|date = 2006|publisher=Lulu|pages=207, 319, 370, 518, search}}</ref> *As catalyst for the fluorination of arylboronic pinacol esters through a Bi(III)/Bi(V) catalytic cycle, mimicking transition metals in electrophilic fluorination.<ref>{{cite journal|doi =10.1126/science.aaz2258 |title = Fluorination of arylboronic esters enabled by bismuth redox catalysis|date = 2020|last1 = Planas|first1 = Oriol|last2 = Wang|first2 = Feng|last3 = Leutzsch|first3 = Markus|last4 = Cornella|first4 = Josep|journal = Science|volume = 367|issue = 6475|pages = 313–317|pmid = 31949081|bibcode = 2020Sci...367..313P|s2cid = 210698047|doi-access = free|hdl = 21.11116/0000-0005-DB57-3|hdl-access = free}}</ref>

== Toxicology and ecotoxicology == :''See also bismuthia, a rare dermatological condition that results from the prolonged use of bismuth.''

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.)<ref name="Kean" /> presumably due to the comparatively low solubility of bismuth salts.<ref name=":0" /> 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.<ref name="Fowler">{{cite book |chapter-url = https://books.google.com/books?id=nKulgztuzL8C&pg=PA433| pages = 433 ff|chapter=Bismuth|title = Handbook on the toxicology of metals|publisher=Academic Press |isbn = 978-0-12-369413-3 |author = Fowler, B.A. |author2 = Sexton M.J. |name-list-style = amp |editor=Nordberg, Gunnar |date= 2007}}</ref>

Bismuth poisoning can occur and has according to some reports been common in relatively recent times.<ref name=":0">{{Cite journal|last=DiPalma|first=Joseph R.|year=2001|title=Bismuth Toxicity, Often Mild, Can Result in Severe Poisonings|journal=Emergency Medicine News|volume=23 |issue=3|page=16|doi=10.1097/00132981-200104000-00012}}</ref><ref name="Lenntech">[http://www.lenntech.com/periodic/elements/bi.htm Data on Bismuth's health and environmental effects]. Lenntech.com. Retrieved on 17 December 2011.</ref> As with lead, bismuth poisoning can result in the formation of a black deposit on the gingiva, known as a bismuth line.<ref name="biline">[http://medical-dictionary.thefreedictionary.com/bismuth+line "Bismuth line"] in ''TheFreeDictionary's Medical dictionary''. Farlex, Inc.</ref><ref>{{cite journal|doi = 10.1111/j.1365-2133.1973.tb01932.x|title = Drug induced changes in pigmentation|date = 1973|last1 = Levantine|first1 = Ashley|last2 = Almeyda|first2 = John|journal = British Journal of Dermatology|volume = 89|pages = 105–12|pmid = 4132858|issue = 1|s2cid = 7175799}}</ref><ref name="Ullmanns"/>{{rp|187–8}} Poisoning may be treated with dimercaprol, but evidence for benefit is unclear.<ref name="WHO2008">{{cite book | title = WHO Model Formulary 2008 | year = 2009 | isbn = 9789241547659 | vauthors = ((World Health Organization)) | veditors = Stuart MC, Kouimtzi M, Hill SR | hdl = 10665/44053 | author-link = World Health Organization | publisher = World Health Organization | hdl-access=free | page=62 }}</ref><ref name="AHFS2016">{{cite web|title=Dimercaprol|url=https://www.drugs.com/monograph/dimercaprol.html|publisher=The American Society of Health-System Pharmacists|access-date= 8 December 2016}}</ref>

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.<ref>{{Cite journal|last=Boriova|display-authors=et al|year=2015|title=Bismuth(III) Volatilization and Immobilization by Filamentous Fungus ''Aspergillus clavatus'' During Aerobic Incubation|journal=Archives of Environmental Contamination and Toxicology|volume=68 |issue=2|pages=405–411|doi=10.1007/s00244-014-0096-5|pmid=25367214|bibcode=2015ArECT..68..405B |s2cid=30197424}}</ref><ref>{{Cite journal|last=Boriova|display-authors=et al|year=2013|title=Bioaccumulation and biosorption of bismuth Bi (III) by filamentous fungus ''Aspergillus clavatus''|url=http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/44/078/44078300.pdf|journal=Student Scientific Conference PriF UK 2013. Proceedings of Reviewed Contributions}}</ref>

== See also == {{Portal|Chemistry}} * Bismuth minerals * Arsenic-bismuth

==Notes== {{Notelist}}

== References == {{Reflist|30em}}

== Cited sources == {{Source-attribution| Brown, R. D., Jr. "Annual Average Bismuth Price", USGS (1998)}}.

== External links == {{Commons}} {{Wiktionary|bismuth}} * [http://www.periodicvideos.com/videos/083.htm Bismuth] at ''The Periodic Table of Videos'' (University of Nottingham) * [http://www.amazingrust.com/Experiments/how_to/Bismuth_Crystals.html Bismuth Crystals – Instructions & Pictures] * usgs.gov (Mineral Commodity Summaries 2025): [https://pubs.usgs.gov/periodicals/mcs2025/mcs2025.pdf#page=46 Bismuth]

{{Periodic table (navbox)}} {{Bismuth compounds}} {{Bismuthides}} {{Authority control}}

Category:Bismuth Category:Chemical elements Category:Minerals in space group 166 Category:Native element minerals Category:Pnictogens Category:Post-transition metals Category:Alchemical substances Category:Trigonal minerals Category:Materials that expand upon freezing Category:Chemical elements with rhombohedral structure