Editing Chemical symbol

{{Short description|Abbreviations used in chemistry}}
{{More citations needed|date=April 2024}}
[[File:Simple Periodic Table Chart-blocks.svg|thumb|upright=2.2|The [[periodic table]], elements being denoted by their symbols]]

'''Chemical symbols''' are the abbreviations used in [[chemistry]], mainly for [[chemical element]]s; but also for [[functional group]]s, chemical compounds, and other entities. '''Element symbols''' for chemical elements, also known as '''atomic symbols''', normally consist of one or two letters from the [[Latin alphabet]] and are written with the first letter capitalised.

==History==
Earlier symbols for chemical elements stem from classical [[Latin]] and [[Greek language|Greek]] vocabulary. For some elements, this is because the material was known in ancient times, while for others, the name is a more recent invention. For example, Pb is the symbol for [[lead]] (''plumbum'' in Latin); Hg is the symbol for [[mercury (element)|mercury]] (''hydrargyrum'' in Greek); and He is the symbol for [[helium]] (a [[Neo-Latin]] name) because helium was not known in [[ancient Roman]] times. Some symbols come from other sources, like W for [[tungsten]] (''Wolfram'' in German) which was not known in Roman times.

A three-letter [[Systematic element name|temporary symbol]] may be assigned to a newly synthesized (or not yet synthesized) element. For example, "Uno" was the temporary symbol for [[hassium]] (element 108) which had the temporary name of ''unniloctium'', based on the digits of its atomic number. There are also some historical symbols that are no longer officially used.

==Extension of the symbol==
[[File:Atomic Symbol Mg.svg|thumb|upright=1.5|Annotated example of an atomic symbol]]
In addition to the letters for the element itself, additional details may be added to the symbol as [[subscript and superscript|superscripts or subscripts]] a particular [[isotope]], [[ionization]], or [[oxidation state]], or other atomic detail.<ref>{{cite report |url= http://old.iupac.org/reports/provisional/abstract04/RB-prs310804/Chap3-3.04.pdf |title= IUPAC Provisional Recommendations: IR-3: Elements and Groups of Elements |date= March 2004 |publisher= [[IUPAC]]}}</ref> A few isotopes have their own specific symbols rather than just an isotopic detail added to their element symbol.

Attached subscripts or superscripts specifying a nuclide or molecule have the following meanings and positions:

*The [[nucleon]] number ([[mass number]]) is shown in the left superscript position (e.g., <sup>14</sup>N). This number defines the specific isotope. Various letters, such as "m" and "f" may also be used here to indicate a [[nuclear isomer]] (e.g., [[technetium-99m|<sup>99m</sup>Tc]]). Alternately, the number here can represent a specific [[quantum state|spin state]] (e.g., [[singlet oxygen|<sup>1</sup>O<sub>2</sub>]]). These details can be omitted if not relevant in a certain context.
*The proton number ([[atomic number]]) may be indicated in the left subscript position (e.g., <sub>64</sub>Gd). The atomic number is redundant to the chemical element, but is sometimes used to emphasize the change of numbers of nucleons in a nuclear reaction.
*If necessary, a state of [[ionization]] or an [[excited state]] may be indicated in the right superscript position (e.g., state of ionization Ca<sup>2+</sup>).
*The number of atoms of an element in a [[molecule]] or [[chemical compound]] is shown in the right subscript position (e.g., N<sub>2</sub> or Fe<sub>2</sub>O<sub>3</sub>). If this number is one, it is normally omitted - the number one is implicitly understood if unspecified.
*A [[radical (chemistry)|radical]] is indicated by a dot on the right side (e.g., Cl<sup>•</sup> for a neutral chlorine atom). This is often omitted unless relevant to a certain context because it is already deducible from the charge and atomic number, as generally true for nonbonded valence electrons in [[skeletal structure]]s.

Many [[functional group]]s also have their own chemical symbol, e.g. Ph for the [[phenyl group]], and Me for the [[methyl group]].

A list of current, dated, as well as proposed and historical signs and symbols is included here with its [[definition|signification]]. Also given is each element's [[atomic number]], [[atomic weight]], or the [[atomic mass]] of the most stable [[isotope]], group and period numbers on the [[periodic table]], and [[etymology]] of the symbol.

==Symbols for chemical elements==
{{sort under}}{{sticky header}}
{| class="wikitable sortable sort-under sticky-header-multi" style="font-size:90%" 
|+
! colspan="4" | List of chemical elements
|-
![[Atomic number|Z]]
!Symbol
!Name
!Origin of name<ref>{{cite web |title=Periodic Table – Royal Society of Chemistry|url=https://www.rsc.org/periodic-table|website=www.rsc.org|language=en}}</ref><ref>{{cite web |title=Online Etymology Dictionary|url=https://www.etymonline.com/|website=etymonline.com|language=en}}</ref>
|-
| 1 ||  H || [[Hydrogen]] || [[Greek language|Greek]] elements ''hydro-'' and ''-gen'', meaning 'water-forming'
|-
| 2 ||  He || [[Helium]] || Greek ''hḗlios'', 'sun'
|-
| 3 ||  Li || [[Lithium]] || Greek ''líthos'', 'stone'
|-
| 4 ||  Be || [[Beryllium]] || [[beryl]], a mineral (ultimately from the name of [[Belur, Karnataka|Belur]] in southern India)
|-
| 5 ||  B || [[Boron]] || [[borax]], a mineral (from [[Arabic]] ''[[wikt: بورق#Arabic|bawraq]]'')
|-
| 6 ||  C || [[Carbon]] || [[Latin]] ''carbo'', '[[coal]]'
|-
| 7 ||  N || [[Nitrogen]] || Greek ''nítron'' and ''-gen'', meaning '[[niter]]-forming'
|-
| 8 ||  O || [[Oxygen]] || Greek ''oxy-'' and ''-gen'', meaning '[[acid]]-forming'
|-
| 9 ||  F || [[Fluorine]] || Latin ''fluere'', 'to flow'
|-
| 10 ||  Ne || [[Neon]] || Greek ''néon'', 'new'
|-
| 11 ||  Na || [[Sodium]] || [[English language|English]] ''soda'' (the symbol Na is derived from [[Neo-Latin]] ''[[wikt:natrium#Latin|natrium]]'', coined from German ''[[wikt:Natron|Natron]]'', '[[natron]]')
|-
| 12 ||  Mg || [[Magnesium]] || [[Magnesia (regional unit)|Magnesia]], a district of Eastern [[Thessaly]] in [[Greece]]
|-
| 13 ||  Al || [[Aluminium]] || [[Aluminium oxide|alumina]], from Latin ''alumen'' (gen. ''alumni''), 'bitter salt, [[alum]]'
|-
| 14 ||  Si || [[Silicon]] || Latin ''silex'', '[[flint]]' (originally ''silicium'')
|-
| 15 ||  P || [[Phosphorus]] || Greek ''phōsphóros'', 'light-bearing'
|-
| 16 ||  S || [[Sulfur]] || Latin ''sulphur'', 'brimstone'
|-
| 17 ||  Cl || [[Chlorine]] || Greek ''chlōrós'', 'greenish yellow'
|-
| 18 ||  Ar || [[Argon]] || Greek ''argós'', 'idle' (because of its [[chemically inert|inertness]])
|-
| 19 ||  K || [[Potassium]] || Neo-Latin ''potassa'', '[[potash]]' (the symbol K is derived from Latin ''[[wikt:kalium#Latin|kalium]]'')
|-
| 20 ||  Ca || [[Calcium]] || Latin ''calx'', '[[lime (material)|lime]]'
|-
| 21 ||  Sc || [[Scandium]] || Latin ''Scandia'', '[[Scandinavia]]'
|-
| 22 ||  Ti || [[Titanium]] || [[Titan (mythology)|Titans]], the sons of the Earth goddess of Greek mythology
|-
| 23 ||  V || [[Vanadium]] || [[List of names of Freyja|Vanadis]], an [[Old Norse]] name for the Scandinavian goddess [[Freyja]]
|-
| 24 ||  Cr || [[Chromium]] || Greek ''chróma'', 'colour'
|-
| 25 ||  Mn || [[Manganese]] || corrupted from ''[[wikt:magnesia#Latin|magnesia]] [[wikt:negra#Latin|negra]]''; see [[Magnesium]]
|-
| 26 ||  Fe || [[Iron]] || English word (the symbol Fe is derived from Latin ''[[wikt:ferrum#Latin|ferrum]]'')
|-
| 27 ||  Co || [[Cobalt]] || [[German language|German]] ''[[wikt:Kobold#German|Kobold]]'', '[[goblin]]'
|-
| 28 ||  Ni || [[Nickel]] || Nickel, a mischievous [[sprite (folklore)|sprite]] of German miner mythology
|-
| 29 ||  Cu || [[Copper]] || English word, from Latin ''[[wikt:cuprum#Latin|cuprum]]'', from Ancient Greek [[wikt:Κύπρος#Ancient Greek|Kýpros]] '[[Cyprus]]'
|-
| 30 ||  Zn || [[Zinc]] || Most likely from German ''[[wikt:Zinke#German|Zinke]]'', 'prong' or 'tooth', though some suggest [[Persian language|Persian]] ''[[wikt:سنگ#Persian|sang]]'', 'stone'
|-
| 31 ||  Ga || [[Gallium]] || Latin ''[[Gallia]]'', 'France'
|-
| 32 ||  Ge || [[Germanium]] || Latin ''[[Germania]]'', 'Germany'
|-
| 33 ||  As || [[Arsenic]] || [[French language|French]] ''[[wikt:arsenic#Middle French|arsenic]]'', from Greek ''[[wikt:ἀρσενικόν#Ancient Greek|arsenikón]]'' 'yellow arsenic' (influenced by ''[[wikt:ἀρσενικός#Ancient Greek|arsenikós]]'', 'masculine' or 'virile'), from a [[West Asia]]n [[wanderword]] ultimately from [[Old Iranian]] ''*zarniya-ka'', 'golden'
|-
| 34 ||  Se || [[Selenium]] || Greek ''[[wikt:σελήνη#Ancient Greek|selḗnē]]'', 'moon'
|-
| 35 ||  Br || [[Bromine]] || Greek ''[[wikt:βρῶμος#Ancient Greek|brômos]]'', 'stench'
|-
| 36 ||  Kr || [[Krypton]] || Greek ''[[wikt:κρυπτός#Ancient Greek|kryptós]]'', 'hidden'
|-
| 37 ||  Rb || [[Rubidium]] || Latin ''[[wikt:rubidus#Latin|rubidus]]'', 'deep red'
|-
| 38 ||  Sr || [[Strontium]] || [[Strontian]], a village in [[Scotland]]
|-
| 39 ||  Y || [[Yttrium]] || [[Ytterby]], a village in Sweden
|-
| 40 ||  Zr || [[Zirconium]] || [[zircon]], a mineral
|-
| 41 ||  Nb || [[Niobium]] || [[Niobe]], daughter of king [[Tantalus]] from Greek mythology
|-
| 42 ||  Mo || [[Molybdenum]] || Greek [[wikt:μολύβδαινα#Ancient Greek|molýbdaina]], 'piece of [[lead]]', from ''[[wikt:μόλυβδος#Ancient Greek|mólybdos]]'', 'lead'
|-
| 43 ||  Tc || [[Technetium]] || Greek ''[[wikt:τεχνητός#Ancient Greek|tekhnētós]]'', 'artificial'
|-
| 44 ||  Ru || [[Ruthenium]] || Neo-Latin ''[[Ruthenia]]'', '[[Russia]]'
|-
| 45 ||  Rh || [[Rhodium]] || Greek ''[[wikt:ῥοδόεις#Ancient Greek|rhodóeis]]'', '[[Rose (colour)|rose-coloured]]', from [[wikt:ῥόδον#Ancient Greek|rhódon]], '[[rose]]'
|-
| 46 ||  Pd || [[Palladium]] || the asteroid [[2 Pallas|Pallas]], considered a planet at the time
|-
| 47 ||  Ag || [[Silver]] || English word (The symbol derives from Latin ''[[wikt:argentum#Latin|argentum]]'')
|-
| 48 ||  Cd || [[Cadmium]] || Neo-Latin ''[[wikt:cadmia#Latin|cadmia]]'', from King [[Kadmos]]
|-
| 49 ||  In || [[Indium]] || Latin ''[[wikt:indicum#Latin|indicum]]'', '[[indigo]]' (colour found in its spectrum)
|-
| 50 ||  Sn || [[Tin]] || English word (The symbol derives from Latin ''[[wikt:stannum#Latin|stannum]]'')
|-
| 51 ||  Sb || [[Antimony]] || Latin ''[[wikt:antimonium#Latin|antimonium]]'', [[Antimony#Etymology|the origin of which]] is uncertain: [[folk etymology|folk etymologies]] suggest it is derived from Greek ''[[wikt:ἀντί#Ancient Greek|antí]]'' ('against') + ''[[wikt:μόνος#Ancient Greek|mónos]]'' ('alone'), or [[Old French]] ''anti-[[wikt:moine#French|moine]]'', 'Monk's bane', but it could plausibly be from or related to Arabic ''[[wikt:إثمد#Arabic|ʾiṯmid]]'', 'antimony', reformatted as a Latin word. (The symbol derives from Latin ''[[wikt:stibium#Latin|stibium]]'' '[[stibnite]]'.)
|-
| 52 ||  Te || [[Tellurium]] || Latin ''[[wikt:tellus#Latin|tellus]]'', 'the ground, earth'
|-
| 53 ||  I || [[Iodine]] || French ''[[wikt:#French|iode]]'', from Greek ''[[wikt:ἰοειδής#Ancient Greek|ioeidḗs]]'', 'violet'
|-
| 54 ||  Xe || [[Xenon]] || Greek ''[[wikt:ξένον#Ancient Greek|xénon]]'', neuter form of [[wikt:ξένος#Ancient Greek|xénos]] 'strange'
|-
| 55 ||  Cs || [[Caesium]] || Latin ''[[wikt:caesius#Latin|caesius]]'', 'sky-blue'
|-
| 56 ||  Ba || [[Barium]] || Greek ''[[wikt:βαρύς#Ancient Greek|barýs]]'', 'heavy'
|-
| 57 ||  La || [[Lanthanum]] || Greek ''[[wikt:λᾰνθᾰ́νειν#Ancient Greek|lanthánein]]'', 'to lie hidden'
|-
| 58 ||  Ce || [[Cerium]] || the dwarf planet [[Ceres (dwarf planet)|Ceres]], considered a planet at the time
|-
| 59 ||  Pr || [[Praseodymium]] || Greek ''[[wikt:πράσιος#Ancient Greek|prásios]] [[wikt:δίδυμος#Ancient Greek|dídymos]]'', 'green twin'
|-
| 60 ||  Nd || [[Neodymium]] || Greek ''[[wikt:νέος#Ancient Greek|néos]] [[wikt:δίδυμος#Ancient Greek|dídymos]]'', 'new twin'
|-
| 61 ||  Pm || [[Promethium]] || [[Prometheus]] of Greek mythology
|-
| 62 ||  Sm || [[Samarium]] || [[samarskite]], a mineral named after Colonel [[Vasili Samarsky-Bykhovets]], Russian mine official
|-
| 63 ||  Eu || [[Europium]] || [[Europe]]
|-
| 64 ||  Gd || [[Gadolinium]] || [[gadolinite]], a mineral named after [[Johan Gadolin]], Finnish chemist, physicist and mineralogist
|-
| 65 ||  Tb || [[Terbium]] || [[Ytterby]], a village in Sweden
|-
| 66 ||  Dy || [[Dysprosium]] || Greek ''[[wikt:δυσπρόσιτος#Ancient Greek|dysprósitos]]'', 'hard to get'
|-
| 67 ||  Ho || [[Holmium]] || Neo-Latin ''Holmia'', '[[Stockholm]]'
|-
| 68 ||  Er || [[Erbium]] || [[Ytterby]], a village in Sweden
|-
| 69 ||  Tm || [[Thulium]] || [[Thule]], the ancient name for an unclear northern location
|-
| 70 ||  Yb || [[Ytterbium]] || [[Ytterby]], a village in Sweden
|-
| 71 ||  Lu || [[Lutetium]] || Latin ''[[Lutetia]]'', '[[Paris]]'
|-
| 72 ||  Hf || [[Hafnium]] || Neo-Latin ''Hafnia'', '[[Copenhagen]]' (from [[Danish language|Danish]] ''[[wikt:havn#Danish|havn]]'')
|-
| 73 ||  Ta || [[Tantalum]] || King [[Tantalus]], father of Niobe from Greek mythology
|-
| 74 ||  W || [[Tungsten]] || Swedish ''[[wikt:tung#Swedish|tung]] [[wikt:sten#Swedish|sten]]'', 'heavy stone' (The symbol is from ''wolfram'', the old name of the tungsten mineral [[wolframite]])
|-
| 75 ||  Re || [[Rhenium]] || Latin ''[[wikt:Rhenus#Latin|Rhenus]]'', '[[the Rhine]]'
|-
| 76 ||  Os || [[Osmium]] || Greek ''[[wikt:ὀσμή#Ancient Greek|osmḗ]]'', '[[odour|smell]]'
|-
| 77 ||  Ir || [[Iridium]] || [[Iris (mythology)|Iris]], the Greek goddess of the rainbow
|-
| 78 ||  Pt || [[Platinum]] || [[Spanish language|Spanish]] ''[[wikt:platina#Spanish|platina]]'', 'little silver', from ''[[wikt:plata#Spanish|plata]]'' 'silver'
|-
| 79 ||  Au || [[Gold]] || English word (The symbol derives from Latin ''[[wikt:aurum#Latin|aurum]]'')
|-
| 80 ||  Hg || [[Mercury (element)|Mercury]] || [[Mercury (mythology)|Mercury]], Roman god of commerce, communication, and luck, known for his speed and mobility (The symbol is from the element's Latin name ''[[wikt:hydrargyrum#Latin|hydrargyrum]]'', derived from Greek ''[[wikt:ὑδράργυρος#Ancient Greek|hydrárgyros]]'', 'water-[[silver]]')
|-
| 81 ||  Tl || [[Thallium]] || Greek ''[[wikt:θαλλός#Ancient Greek|thallós]]'', 'green shoot or twig'
|-
| 82 ||  Pb || [[Lead]] || English word (The symbol derives from Latin ''[[wikt:plumbum#Latin|plumbum]]'')
|-
| 83 ||  Bi || [[Bismuth]] || German [[wikt:#Wismut|Wismut]], from [[wikt:weiß#German|weiß]] [[wikt:Masse#German|Masse]] 'white mass', unless from Arabic
|-
| 84 ||  Po || [[Polonium]] || Latin ''[[wikt:Polonia#Latin|Polonia]]'', '[[Poland]]' (the home country of [[Marie Curie]])
|-
| 85 ||  At || [[Astatine]] || Greek ''[[wikt:ἄστατος#Ancient Greek|ástatos]]'', 'unstable'
|-
| 86 ||  Rn || [[Radon]] || [[radium]]
|-
| 87 ||  Fr || [[Francium]] || [[France]]
|-
| 88 ||  Ra || [[Radium]] || French ''radium'', from Latin ''[[wikt:radius#Latin|radius]]'', '[[ray (optics)|ray]]'
|-
| 89 ||  Ac || [[Actinium]] || Greek ''[[wikt:ἀκτίς#Ancient Greek|aktís]]'', 'ray'
|-
| 90 ||  Th || [[Thorium]] || [[Thor]], the Scandinavian god of thunder
|-
| 91 ||  Pa || [[Protactinium]] || [[wikt:proto-#English|proto-]] (from Greek ''[[wikt:πρῶτος#Ancient Greek|prôtos]]'', 'first, before') + [[actinium]], which is produced through the radioactive decay of protactinium
|-
| 92 ||  U || [[Uranium]] || [[Uranus]], the seventh planet in the Solar System
|-
| 93 ||  Np || [[Neptunium]] || [[Neptune]], the eighth planet in the Solar System
|-
| 94 ||  Pu || [[Plutonium]] || the dwarf planet [[Pluto]], considered the ninth planet in the Solar System at the time
|-
| 95 ||  Am || [[Americium]] || [[The Americas]], as the element was first synthesised on the continent, by analogy with [[europium]]
|-
| 96 ||  Cm || [[Curium]] || [[Pierre Curie]] and [[Marie Curie]], French physicists and chemists
|-
| 97 ||  Bk || [[Berkelium]] || [[Berkeley, California|Berkeley]], California, where the element was first synthesised, by analogy with [[terbium]]
|-
| 98 ||  Cf || [[Californium]] || [[State of California|California]], where the element was first synthesised
|-
| 99 ||  Es || [[Einsteinium]] || [[Albert Einstein]], German physicist
|-
| 100 ||  Fm || [[Fermium]] || [[Enrico Fermi]], Italian physicist
|-
| 101 ||  Md || [[Mendelevium]] || [[Dmitri Mendeleev]], Russian chemist and inventor who proposed the [[periodic table]]
|-
| 102 ||  No || [[Nobelium]] || [[Alfred Nobel]], Swedish chemist and engineer
|-
| 103 ||  Lr || [[Lawrencium]] || [[Ernest O. Lawrence]], American physicist
|-
| 104 ||  Rf || [[Rutherfordium]] || [[Ernest Rutherford]], New Zealand chemist and physicist
|-
| 105 ||  Db || [[Dubnium]] || [[Dubna]], Russia, where the [[Joint Institute for Nuclear Research]] is located
|-
| 106 ||  Sg || [[Seaborgium]] || [[Glenn T. Seaborg]], American chemist
|-
| 107 ||  Bh || [[Bohrium]] || [[Niels Bohr]], Danish physicist
|-
| 108 ||  Hs || [[Hassium]] || Neo-Latin ''Hassia'', '[[Hesse]]' (a state in Germany)
|-
| 109 ||  Mt || [[Meitnerium]] || [[Lise Meitner]], Austrian physicist
|-
| 110 ||  Ds || [[Darmstadtium]]|| [[Darmstadt]], Germany, where the element was first synthesised
|-
| 111 ||  Rg || [[Roentgenium]] || [[Wilhelm Conrad Röntgen]], German physicist
|-
| 112 ||  Cn || [[Copernicium]] || [[Nicolaus Copernicus]], Polish astronomer
|-
| 113 ||  Nh || [[Nihonium]] || [[Japanese language|Japanese]] ''[[wikt:日本#Japanese|Nihon]]'', '[[Japan]]' (where the element was first synthesised)
|-
| 114 ||  Fl || [[Flerovium]] || [[Flerov Laboratory of Nuclear Reactions]], part of [[Joint Institute for Nuclear Research|JINR]], where the element was synthesised; itself named after [[Georgy Flyorov]], Russian physicist
|-
| 115 ||  Mc || [[Moscovium]] || [[Moscow Oblast]], Russia, where the element was first synthesised
|-
| 116 ||  Lv || [[Livermorium]] || [[Lawrence Livermore National Laboratory]] in [[Livermore, California]], which collaborated with [[Joint Institute for Nuclear Research|JINR]] on its synthesis
|-
| 117 ||  Ts || [[Tennessine]] || [[Tennessee]], United States
|-
| 118 ||  Og || [[Oganesson]] || [[Yuri Oganessian]], Russian physicist
|-
|}

==Symbols and names not currently used==
{{More citations needed|section|date=May 2018}}
The following is a list of symbols and names formerly used or suggested for elements, including symbols for [[placeholder name]]s and names given by discredited claimants for discovery.
{{sticky header}}
{| class="wikitable sortable sticky-header" style
!Symbol!!Name!!Atomic<br/>number!!Notes!!Why not<br/>used!!Refs
|-
|A||[[Argon]]||18||A used for Argon until 1957. Current symbol is '''Ar'''. ||<ref group=nb name="why_not_used6">Name changed due to a standardization of, modernization of, or update to older formerly-used symbol.</ref> || <ref name="Holden2004">{{cite web |last=Holden |first=N. E. |date=12 March 2004 |title=History of the Origin of the Chemical Elements and Their Discoverers |url=https://www.nndc.bnl.gov/content/elements.html |publisher=[[National Nuclear Data Center]]}}</ref>
|-
|Ab||Alabamine||85||Discredited claim to discovery of [[astatine]]. ||<ref group=nb name="why_not_used7">Name designated by discredited/disputed claimant.</ref> || <ref name="leal">{{cite journal |doi= 10.1007/s10699-013-9326-y |title= The Forgotten Names of Chemical Elements |year= 2013 |author= Leal, João P. |journal= [[Foundations of Science]] |volume= 19 |issue= 2 |pages= 175–183|s2cid= 254511660 }}</ref><ref name="encyclopediaofalabama.org">{{Cite web|url=http://www.encyclopediaofalabama.org/article/h-1672|title=Fred Allison|website=Encyclopedia of Alabama|first1 = Lindy|last1= Biggs|first2=Stephen|last2= Knowlton|date = 3 February 2022}}</ref>
|-
|Ad||Aldebaranium||70||Former name for [[ytterbium]]. ||<ref group=nb name="why_not_used7" /> ||
|-
|Ah||[[Anglohelvetium]]||85||Discredited claim to discovery of [[astatine]]. ||<ref group=nb name="why_not_used7" /> || <ref name="Fontanietal" />
|-
|Ak||Alkalinium||87||Discredited claim to discovery of [[francium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" />
|-
|Am||Alabamine||85||Discredited claim to discovery of [[astatine]]. The symbol Am is now used for [[americium]].||<ref group=nb name="why_not_used7" /> || <ref name="leal" /><ref name="encyclopediaofalabama.org" />
|-
|An||Athenium||99||Proposed name for [[einsteinium]]. ||<ref group=nb name="why_not_used8">Name proposed prior to discovery/creation of element or prior to official renaming of a placeholder name.</ref> ||
|-
|Ao||Ausonium||93||Discredited claim to discovery of [[neptunium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" />
|-
|At||Austriacum||84||Discredited claim to discovery of [[polonium]]. The symbol At is now used for [[astatine]].||<ref group=nb name="why_not_used7" /> ||
|-
|Az||Azote||7||Former name for [[nitrogen]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Bo||Bohemium||93||Discredited claim to discovery of [[neptunium]]. ||<ref group=nb name="why_not_used7" /> ||
|-
|Bo||[[Boron]]||5||Current symbol is '''B'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Bv||Brevium||91||Former name for [[protactinium]]-234. ||<ref group=nb name="why_not_used6" /> ||
|-
|Bz||[[Berzelium]]||90||[[Charles Baskerville|Baskerville]] wrongly believed berzelium was a new element. Was actually [[thorium]]. || || <ref name="Fontanietal">{{cite book |last1=Fontani|first1= Marco|author-link1= Marco Fontani|last2= Costa|first2= Mariagrazia|last3= Orna|first3= Mary Virginia|date= 2014|title= The Lost Elements: The Periodic Table's Shadow Side|publisher= [[Oxford University Press]]|isbn=9780199383344}}</ref>
|-
|Cb||Columbium||41||Former name for [[niobium]]. ||<ref group=nb name="why_not_used6" /> || <ref name="leal" /><ref name="Fontanietal" />
|-
|Ch||[[Chromium]]||24||Current symbol is '''Cr'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Cl||Columbium||41||Former name for [[niobium]]. The symbol Cl is now used for [[chlorine]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Cm||Catium||87||Proposed name for [[francium]]. The symbol Cm is now used for [[curium]]. ||<ref group=nb name="why_not_used8" /> ||
|-
|Cn||[[Carolinium]]||90||[[Charles Baskerville|Baskerville]] wrongly believed carolinium to be a new element. Was actually [[thorium]]. The symbol Cn is now used for [[copernicium]]. || || <ref name="Fontanietal" />
|-
|Cp||Cassiopeium||71||Former name for [[lutetium]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Cp||Copernicium||112||Current symbol is '''Cn'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Ct||Celtium||72||Discredited claim to discovery of [[hafnium]]. ||<ref group=nb name="why_not_used7" /> ||
|-
|Ct||Centurium||100||Proposed name for [[fermium]]. ||<ref group=nb name="why_not_used8" /> ||
|-
|Cy||Cyclonium||61||Proposed name for [[promethium]]. ||<ref group=nb name="why_not_used8" /> ||
|-
|D||[[Didymium]]||59/60||Mixture of the elements [[praseodymium]] and [[neodymium]]. [[Carl Gustaf Mosander|Mosander]] wrongly believed didymium to be an element. || || <ref name="chemistryexplained">[http://was.chemistryexplained.com/elements/P-T/Praseodymium.html Praseodymium] {{Webarchive|url=https://web.archive.org/web/20181008051256/http://www.chemistryexplained.com/elements/P-T/Praseodymium.html |date=2018-10-08 }} on was.chemistryexplained.com<!-- (blacklisted site; needs replacing) -->.</ref>
|-
|Da||[[Davyum]]||43||Discredited claim to discovery of [[technetium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" />
|-
|Db||Dubhium||69||[[Josef Maria Eder|Eder]] wrongly believed dubhium to be a new element. Was actually [[thulium]]. The symbol Db is now used for [[dubnium]]. || ||
|-
|Db||[[Dubnium]]||104||Proposed name for [[rutherfordium]]. The symbol and name were instead used for element 105. ||<ref group=nb name="why_not_used6" /><ref group=nb name="why_not_used8" /> || <ref name="leal" />
|-
|Dc||[[Decipium]]||62||[[Marc Delafontaine|Delafontaine]] wrongly believed decipium to be a new element. Was actually [[samarium]]. || ||
|-
|Dc||Dvicaesium||87||Name given by Mendeleev to an as of then undiscovered element. When discovered, [[francium]] closely matched the prediction. ||<ref group=nb name="why_not_used8" /><ref group=nb name="why_not_used9" /> ||
|-
|De||Denebium||69||[[Josef Maria Eder|Eder]] wrongly believed denebium to be a new element. Was actually [[thulium]]. || ||
|-
|Di||[[Didymium]]||59/60||Mixture of the elements [[praseodymium]] and [[neodymium]]. [[Carl Gustaf Mosander|Mosander]] wrongly believed didymium to be an element. || || <ref name="chemistryexplained" />
|-
|Do||Dor||85||Discredited claim to discovery of [[astatine]] made by [[Horia Hulubei]] and [[Yvette Cauchois]]. ||<ref group=nb name="why_not_used7" /> || <ref name="Fontanietal" />
|-
|Dn||Dubnadium||118||Proposed name for [[oganesson]]. ||<ref group=nb name="why_not_used8" /> ||
|-
|Dp||[[Decipium]]||62||[[Marc Delafontaine|Delafontaine]] wrongly believed decipium to be a new element. Was actually [[samarium]]. || ||
|-
|Ds||[[Dysprosium]]||66||Current symbol is '''Dy'''. The symbol Ds is now used for [[darmstadtium]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Dt||Dvitellurium||84||Name given by Mendeleev to an as of then undiscovered element. When discovered, [[polonium]] closely matched the prediction. ||<ref group=nb name="why_not_used8" /><ref group=nb name="why_not_used9" /> ||
|-
|E||[[Einsteinium]]||99||Current symbol is '''Es'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|E||[[Erbium]]||68||Current symbol is '''Er'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Ea||Ekaaluminium||31||Name given by [[Dmitri Mendeleev|Mendeleev]] to an as of then undiscovered element. When discovered, [[gallium]] closely matched the prediction. ||<ref group=nb name="why_not_used8" /><ref group=nb name="why_not_used9">Temporary placeholder name.</ref> ||
|-
|Eb||Ekaboron||21||Name given by [[Dmitri Mendeleev|Mendeleev]] to an as of then undiscovered element. When discovered, [[scandium]] closely matched the prediction. ||<ref group=nb name="why_not_used8" /><ref group=nb name="why_not_used9" /> || <ref name="leal" />
|-
|Eb||Erebodium||42||Alexander Pringle wrongly believed erebodium to be a new element. Was likely [[molybdenum]]. || ||<ref name="Fontanietal" />
|-
|El||Ekaaluminium||31||Name given by Mendeleev to an as of then undiscovered element. When discovered, [[gallium]] closely matched the prediction. ||<ref group=nb name="why_not_used8" /><ref group=nb name="why_not_used9" /> || <ref name="leal" />
|-
|Em||Ekamanganese||43||Name given by Mendeleev to an as of then undiscovered element. When discovered, [[technetium]] closely matched the prediction. ||<ref group=nb name="why_not_used8" /><ref group=nb name="why_not_used9" /> || <ref name="leal" />
|-
|Em||Emanation||86||Also called "radium emanation", the name was originally given by [[Friedrich Ernst Dorn]] in 1900.<br/>In 1923, this element officially became [[radon]] (the name given at one time to <sup>222</sup>Rn, an isotope identified in the decay chain of [[radium]]). ||<ref group=nb name="why_not_used6" /> || <ref name="leal" />
|-
|Em||Emanium||89||Alternate name formerly proposed for [[actinium]]. ||<ref group=nb name="why_not_used8" /> ||
|-
|Es||Ekasilicon||32||Name given by Mendeleev to a then undiscovered element. When discovered, [[germanium]] closely matched the prediction.<br/>The symbol Es is now used for [[einsteinium]]. ||<ref group=nb name="why_not_used8" /><ref group=nb name="why_not_used9" /> || <ref name="leal" />
|-
|Hs||Hesperium||94||Discredited claim to discovery of [[plutonium]]. The symbol Hs is now used for [[hassium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" /><ref name="Fontanietal" />
|-
|Et||Ekatantalum||91||Name given by Mendeleev to an as of then undiscovered element. When discovered, [[protactinium]] closely matched the prediction. ||<ref group=nb name="why_not_used8" /><ref group=nb name="why_not_used9" /> ||
|-
|Ex||Euxenium||72||Discredited claim to discovery of [[hafnium]]. ||<ref group=nb name="why_not_used7" /> ||<ref name="Fontanietal" />
|-
|Fa||[[Francium]]||87||Current symbol is '''Fr'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Fl||Florentium||61||Discredited claim to discovery of [[promethium]]. The symbol Fl is now used for [[flerovium]]. ||<ref group=nb name="why_not_used7" /> ||
|-
|Fl||[[Fluorine]]||9||Current symbol is '''F'''. The symbol Fl is now used for [[flerovium]].||<ref group=nb name="why_not_used6" /> ||
|-
|Fr||Florentium||61||Discredited claim to discovery of [[promethium]]. The symbol Fr is now used for [[francium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" />
|-
|G||Glucinium||4||Former name for [[beryllium]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Gh||Ghiorsium||118||Discredited claim to discovery of [[oganesson]]. ||<ref group=nb name="why_not_used7" /> ||
|-
|Gl||Glucinium||4||Former name for [[beryllium]]. ||<ref group=nb name="why_not_used6" /> || <ref name="leal" />
|-
|Ha||Hahnium||105||Proposed name for [[dubnium]]. ||<ref group=nb name="why_not_used8" /> ||
|-
|Hn||Hahnium||108||Proposed name for [[hassium]]. ||<ref group=nb name="why_not_used8" /> || <ref name="leal" />
|-
|Hv||[[Helvetium]]||85||Discredited claim to discovery of [[astatine]]. ||<ref group=nb name="why_not_used7" /> || <ref name="Fontanietal" />
|-
|Hy||Mercury||80||Hy from the Greek hydrargyrum for "liquid silver". Current symbol is '''Hg'''. ||<ref group=nb name="why_not_used6" /> || <ref name="Holden2004" />
|-
|I||Iridium||77||Current symbol is '''Ir'''. The symbol I is now used for [[iodine]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Ic||Incognitium||65||[[Eugène-Anatole Demarçay|Demarçay]] wrongly believed incognitium to be a new element. Was actually [[terbium]] mixed with gadolinium. || ||<ref name="Fontanietal" />
|-
|Il||Illinium||61||Discredited claim to discovery of [[promethium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" />
|-
|Il||[[Ilmenium]]||41/73||Mixture of the elements [[niobium]] and [[tantalum]]. R. Hermann wrongly believed ilmenium to be an element. || ||
|-
|Io||Ionium||65||[[Eugène-Anatole Demarçay|Demarçay]] wrongly believed ionium to be a new element. Was actually [[terbium]]. || ||
|-
|J||Jodium||53||Former name for [[iodine]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Jg||Jargonium||72||Discredited claim to discovery of [[hafnium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" />
|-
|Jl||Joliotium||105||Proposed name for [[dubnium]]. ||<ref group=nb name="why_not_used8" /> || <ref name="leal" />
|-
|Jp||Japonium||113||Proposed name for [[nihonium]]. ||<ref group=nb name="why_not_used8" /> ||
|-
|Ka||[[Potassium]]||19||Current symbol is '''K'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Ku||Kurchatovium||104||Proposed name for [[rutherfordium]]. ||<ref group=nb name="why_not_used8" /> || <ref name="leal" />
|-
|L||[[Lithium]]||3||Current symbol is '''Li'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Lw||[[Lawrencium]]||103||Current symbol is '''Lr'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|M||Muriaticum||17||Former name for [[chlorine]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Ma||[[Manganese]]||25||Current symbol is '''Mn'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Ma||Masurium||43||Disputed claim to discovery of [[technetium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" />
|-
|Md||[[Mendelevium]]||97||Proposed name for [[berkelium]]. The symbol and name were later used for element 101. ||<ref group=nb name="why_not_used6" /><ref group=nb name="why_not_used8" /> ||
|-
|Ml||Moldavium||87||Discredited claim to discovery of [[francium]] made by [[Horia Hulubei]] and [[Yvette Cauchois]]. ||<ref group=nb name="why_not_used7" /> || <ref name="Fontanietal" />
|-
|Ms||[[Magnesium]]||12||Current symbol is '''Mg'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Ms||Masrium||88||Discredited claim to discovery of [[radium]]. ||<ref group=nb name="why_not_used7" /> ||
|-
|Ms||Masurium||43||Disputed claim to discovery of [[technetium]]. ||<ref group=nb name="why_not_used7" /> ||
|-
|Ms||Mosandrium||65||[[J. Lawrence Smith (chemist)|Smith]] wrongly believed mosandrium to be a new element. Was actually [[terbium]]. || ||
|-
|Mv||[[Mendelevium]]||101||Current symbol is '''Md'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Ng||Norwegium||72||Discredited claim to discovery of [[hafnium]]. ||<ref group=nb name="why_not_used7" /> ||
|-
|No||Norium||72||Discredited claim to discovery of [[hafnium]]. The symbol No is now used for [[nobelium]]. ||<ref group=nb name="why_not_used7" /> ||
|-
|Np||Neptunium||91||Discredited claim to discovery of [[protactinium]]. The symbol and name were later used for element 93. ||<ref group=nb name="why_not_used7" /> || <ref name="rang">{{cite journal |title= The Period-Table |year= 1895 |author= Rang, F. |journal= The Chemical News and Journal of Physical Science |volume= 72 |pages= 200–201}}</ref>
|-
|Np||Nipponium||43||Discredited claim to discovery of [[technetium]]. The symbol Np is now used for [[neptunium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" />
|-
|Ns||Nielsbohrium||105||Proposed name for [[dubnium]]. ||<ref group=nb name="why_not_used8" /> || <ref name="leal" />
|-
|Ns||Nielsbohrium||107||Proposed name for [[bohrium]]. ||<ref group=nb name="why_not_used8" /> || <ref name="leal" />
|-
|Nt||Niton||86||Former name for [[radon]]. ||<ref group=nb name="why_not_used6" /> || <ref name="leal" />
|-
|Ny||Neoytterbium||70||Former name for [[ytterbium]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|P||Lead||82||Current symbol is '''Pb'''. The symbol P is now used for [[phosphorus]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Pa||Palladium||46||Current symbol is '''Pd'''. The symbol Pa is now used for [[protactinium]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Pe||[[Pelopium]]||41||Former name for [[niobium]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Ph||Phosphorus||15||Current symbol is '''P'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Pl||Palladium||46||Current symbol is '''Pd'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Pm||Polymnestum||33||Alexander Pringle wrongly believed polymnestum to be a new element. Was likely [[arsenic]]. The symbol Pm is now used for [[promethium]]. || ||<ref name="Fontanietal" />
|-
|Po||[[Potassium]]||19||Current symbol is '''K'''. The symbol Po is now used for [[polonium]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Pp||[[Philippium]]||67||[[Marc Delafontaine|Delafontaine]] discovered a new element and named it philippium. [[Per Teodor Cleve]] isolated it and renamed it [[holmium]]. || ||<ref name="Fontanietal" />
|-
|R||Rhodium||45||Current symbol is '''Rh'''. (The symbol is now sometimes used for an [[alkyl group]].) ||<ref group=nb name="why_not_used6" /> ||
|-
|Rd||Radium||88||Current symbol is '''Ra'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Rf||[[Rutherfordium]]||106||Proposed name for [[seaborgium]]. The symbol and name were instead used for element 104. ||<ref group=nb name="why_not_used6" /><ref group=nb name="why_not_used8" /> || <ref name="leal" />
|-
|Ro||Rhodium||45||Current symbol is '''Rh'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Sa||[[Samarium]]||62||Current symbol is '''Sm'''. ||<ref group=nb name="why_not_used6" /> || <ref name="leal" />
|-
|So||[[Sodium]]||11||Current symbol is '''Na'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Sq||Sequanium||93||Discredited claim to discovery of [[neptunium]] made by [[Horia Hulubei]] and [[Yvette Cauchois]]. ||<ref group=nb name="why_not_used7" /> ||<ref name="Fontanietal" />
|-
|St||[[Antimony]]||51||Current symbol is '''Sb'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|St||[[Tin]]||50||Current symbol is '''Sn'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Tm||Trimanganese||75||Name given by Mendeleev to an as of then undiscovered element. When discovered, [[rhenium]] closely matched the prediction. The symbol Tm is now used for [[thulium]]. ||<ref group=nb name="why_not_used8" /><ref group=nb name="why_not_used9" /> ||
|-
|Tn||[[Tungsten]]||74||Current symbol is '''W'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Tr||[[Terbium]]||65||Current symbol is '''Tb'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Tu||[[Thulium]]||69||Current symbol is '''Tm'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Tu||Tungsten||74||Current symbol is '''W'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Ur||Uralium||75||Discredited claim to discovery of [[rhenium]]. ||<ref group=nb name="why_not_used7" /> ||
|-
|Ur||[[Uranium]]||92||Current symbol is '''U'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Vc||[[Victorium]]||64||[[William Crookes|Crookes]] wrongly believed victorium to be a new element. Was actually [[gadolinium]]. || ||
|-
|Vi||[[Victorium]]||64||[[William Crookes|Crookes]] wrongly believed victorium to be a new element. Was actually [[gadolinium]]. || ||
|-
|Vi||Virginium||87||Discredited claim to discovery of [[francium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" />
|-
|Vm||Virginium||87||Discredited claim to discovery of [[francium]]. ||<ref group=nb name="why_not_used7" /> || <ref name="leal" />
|-
|Va||[[Vanadium]]||23||Current symbol is '''V'''. ||<ref group=nb name="why_not_used6" /> ||
|-
|Wo||[[Wolfram (chemical)|Wolfram]]||74||Former name for [[tungsten]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|X||[[Xenon]]||54||Current symbol is '''Xe'''. The symbol X is now used for any [[halogen]]. ||<ref group=nb name="why_not_used6" /> ||
|-
|Yt||[[Yttrium]]||39||Current symbol is '''Y'''. ||<ref group=nb name="why_not_used6" /> || <ref name="leal" />
|}

===Systematic chemical symbols===

These symbols are based on [[systematic element name]]s, which are now replaced by trivial (non-systematic) element names and symbols. Data is given in order of: [[atomic number]], systematic symbol, systematic name; trivial symbol, trivial name.
* 101: Unu, unnilunium; Md, [[mendelevium]].
* 102: Unb, unnilbium; No, [[nobelium]].
* 103: Unt, unniltrium; Lr, [[lawrencium]].
* 104: Unq, unnilquadium; Rf, [[rutherfordium]].
* 105: Unp, unnilpentium; Db, [[dubnium]].
* 106: Unh, unnilhexium; Sg, [[seaborgium]].
* 107: Uns, unnilseptium; Bh, [[bohrium]].
* 108: Uno, unniloctium; Hs, [[hassium]].
* 109: Une, unnilennium; Mt, [[meitnerium]].
* 110: Uun, ununnilium; Ds, [[darmstadtium]].
* 111: Uuu, unununium; Rg, [[roentgenium]].
* 112: Uub, ununbium; Cn, [[copernicium]].
* 113: Uut, ununtrium; Nh, [[nihonium]].
* 114: Uuq, ununquadium; Fl, [[flerovium]].
* 115: Uup, ununpentium; Mc, [[moscovium]].
* 116: Uuh, ununhexium; Lv, [[livermorium]].
* 117: Uus, ununseptium; Ts, [[tennessine]].
* 118: Uuo, ununoctium; Og, [[oganesson]].

When elements beyond oganesson (starting with [[ununennium]], Uue, element 119), are discovered; their systematic name and symbol will presumably be superseded by a trivial name and symbol.

===Alchemical symbols===
{{main|Alchemical symbols}}
The [[alchemical symbols|following ideographic symbols]] were used in [[alchemy]] to denote elements known since ancient times. Not included in this list are spurious elements, such as the [[classical element]]s [[fire (classical element)|fire]] and [[water (classical element)|water]] or [[phlogiston]], and substances now known to be compounds. Many more symbols were in at least sporadic use: one early 17th-century alchemical manuscript lists 22 symbols for mercury alone.<ref name=Crosland/>

Planetary names and symbols for the metals – the seven planets and seven metals known since Classical times in Europe and the Mideast<!--Americans also knew of platinum, but Europeans didn't discover that was another metal until the 18th c.--> – was ubiquitous in alchemy. The association of what are anachronistically known as [[planetary metal]]s started breaking down with the discovery of antimony, bismuth and zinc in the 16th century. Alchemists would typically call the metals by their planetary names, e.g. "Saturn" for lead and "Mars" for iron; compounds of tin, iron and silver continued to be called "jovial", "martial" and "lunar"; or "of Jupiter", "of Mars" and "of the moon", through the 17th century. The tradition remains today with the name of the element mercury, where chemists decided the planetary name was preferable to common names like "quicksilver", and in a few archaic terms such as [[wikt:lunar caustic|lunar caustic]] (silver nitrate) and [[saturnism]] (lead poisoning).<ref name=Crosland>Maurice Crosland (2004) ''Historical Studies in the Language of Chemistry''</ref>

{{sticky header}}
{| class="wikitable sticky-header" style
|+ Alchemical symbols for the modern elements
!colspan=2|Symbol!!Element!!Atomic<br/>number!!Notes
|-
| {{nowrap|[[Image:Phosphorus symbol.svg|24px]][[File:Phosphorus symbol (inverted).svg|24px]]}} || style="text-align:center;" |  || [[Phosphorus]] || 15 || (discovered late)
|-
| style="text-align:center;" | [[File:Sulphur symbol (fixed width).svg|24px]] || style="text-align:center;" | {{big|🜍}} || [[Sulfur]] || 16 || used by Newton
|-
| style="text-align:center;" | [[File:Manganese symbol (Bergman).svg|24px]] ||  || [[Manganese]] || 25 || late; used by [[Torbern Bergman]] (1775)
|-
| style="text-align:center;" | [[file:Mars symbol (fixed width).svg|24px]] || style="text-align:center;" | {{big|♂}} || [[Iron]] || 26 || classical planetary metal of Mars
|-
| style="text-align:center;" | [[File:Alkali symbol.svg|24px]] || style="text-align:center;" | {{big|🜶}} || [[Cobalt]] || 27 || late; used by Bergman
|-
| style="text-align:center;" | [[File:Nickel symbol.svg|24px]] || || [[Nickel]] || 28 || late; used by Bergman (old positional variant of arsenic, previously used for [[wikt:regulus|regulus]] of sulfur)
|-
| style="text-align:center;" | [[File:Zinc symbol (fixed width).svg|24px]] || || [[Zinc]] || 30 || late; used by Bergman 
|-
| style="text-align:center;" | [[file:Venus symbol (fixed width).svg|24px]] || style="text-align:center;" | {{big|♀}} || [[Copper]] || 29 || classical planetary metal of Venus
|-
| style="text-align:center;" | [[File:Arsenic symbol.svg|24px]] || style="text-align:center;" | {{big|🜺}} || [[Arsenic]] || 33 || 
|-
| style="text-align:center;" | [[file:Moon decrescent symbol (fixed width).svg|24px]]  || style="text-align:center;" | {{big|☾}} || rowspan="2" | [[Silver]] || rowspan="2" | 47 || classical planetary metal of the Moon
|-
| style="text-align:center;" | [[file:Silver symbol (alchemical).svg|24px]] || style="text-align:center;" | {{big|🜛}} || 
|-
| style="text-align:center;" | [[file:Jupiter symbol (fixed width).svg|24px]] || style="text-align:center;" | {{big|♃}} || [[Tin]] || 50 || classical planetary metal of Jupiter
|-
| style="text-align:center;" | [[file:Globus cruciger (fixed width).svg|24px]] || style="text-align:center;" | {{big|♁}} || [[Antimony]] || 51 || the newly discovered "eighth metal" was given the symbol for the Earth, which was recognized as a planet by that time
|-
| style="text-align:center;" | [[file:Platinum symbol.svg|24px]] || || rowspan="2" | [[Platinum]] || rowspan="2" | 78 || late; used by Bergman et al.: a compound of ☉ gold and ☾ silver
|-
| style="text-align:center;" | [[file:Uranus symbol (fixed width).svg|24px]] || style="text-align:center;" | {{big|⛢}} || late; symbol invented for the newly discovered planet Uranus so that it could also be used for newly recognized platinum
|-
| style="text-align:center;" | [[File:Sun symbol (medieval).svg|24px]] || style="text-align:center;" | {{big|🜚}} || rowspan="2" | [[Gold]] || rowspan="2" | 79 || classical variant
|-
| style="text-align:center;" | [[file:Sun symbol.svg|24px]] || style="text-align:center;" | {{big|☉}} || medieval variant; planetary metal of the Sun
|-
| style="text-align:center;" | [[file:Mercury symbol (fixed width).svg|24px]] || style="text-align:center;" | {{big|☿}} || [[Mercury (element)|Mercury]] || 80 || classical planetary metal of Mercury
|-
| style="text-align:center;" | [[file:Saturn symbol (fixed width).svg|24px]] || style="text-align:center;" | {{big|♄}} || [[Lead]] || 82 || classical planetary metal of Saturn
|-
| style="text-align:center;" | [[File:Bismuth trident symbol.svg|24px]] || style="text-align:center;" | {{big|♆}} || rowspan=2| [[Bismuth]] || rowspan=2| 83 || used by Newton
|-
| style="text-align:center;" | [[File:Bismuth symbol.svg|24px]] || style="text-align:center;" | {{big|♉︎}} || used by Bergman
|}

===Daltonian symbols===
[[File:Dalton's Element List.jpg|thumb|Dalton's symbols for the more common elements, as of 1806, and the relative weights he calculated. The symbols for magnesium and calcium ("lime") were replaced by 1808, and that for gold was simplified.]]
The following symbols were employed by [[John Dalton]] in the early 1800s as the periodic table of elements was being formulated. Not included in this list are substances now known to be compounds, such as certain [[rare-earth element|rare-earth]] mineral blends. Modern alphabetic notation was introduced in 1814 by [[Jöns Jakob Berzelius]]; its precursor can be seen in Dalton's circled letters for the metals, especially in his augmented table from 1810.<ref>Berzelius, Jöns Jakob. "Essay on the Cause of Chemical Proportions, and on Some Circumstances Relating to Them: Together with a Short and Easy Method of Expressing Them." ''[[Annals of Philosophy]]'' 2, Pp.443–454 (1813); 3, Pp.51–52, 93–106, 244–255, 353–364 (1814); (Subsequently republished in "A Source Book in Chemistry, 1400-1900", eds. Leicester, Henry M. & Herbert S. Klickstein. 1952.)</ref>
A trace of Dalton's conventions also survives in [[ball-and-stick model]]s of molecules, where balls for carbon are black and for oxygen red.

{| class="wikitable" style
|+Daltonian symbols for the elements
!colspan=2|Symbol!!rowspan=2|Dalton's name!!rowspan=2|Modern name!!rowspan=2|Atomic<br/>number!!rowspan=2|Notes!!rowspan=2|Refs
|-
!<small>img.</small>||<small>char.</small>
|-
| [[file:hydrogen symbol (Dalton).svg|24px]] ||<span style="color:red">☉</span>||colspan=2|[[hydrogen]]||1||or <span style="color:red">⊙</span>||<ref name=dalton1808ansocp>{{cite book | last = Dalton | first = John | author-link = John Dalton | date = 1808 | chapter = III: On Chemical Synthesis - Section 1: Explanation of the Plates - Plate 4: Elements | title = A New System of Chemical Philosophy. Part I. | pages = 217–220  | location = [[Manchester]] | publisher = Printed by S. Russell for R. Bickerstaff, [[Strand, London]]}}</ref>
|-
| [[file:beryllium symbol (Dalton).svg|24px]] || ||[[wikt:glucinum|glucine]]||[[beryllium]]||4||alchemical symbol for 'sugar'||<ref name=dalton1810ansocp/>
|-
| [[file:new moon symbol.svg|24px]] ||●||[[wikt:carbone|carbone]], [[carbon]]||[[carbon]]||6|| ||<ref name=dalton1808ansocp/>
|-
| [[file:nitrogen symbol (Dalton).svg|24px]] ||⦶||[[wikt:azote|azote]]||[[nitrogen]]/azote||7||alchemical symbol for [[niter]] ||<ref name=dalton1808ansocp/>
|-
| [[file:oxygen symbol (Dalton).svg|24px]] ||<span style="color:red">○</span>||colspan=2|[[oxygen]]||8||or <span style="color:red">◯</span>||<ref name=dalton1808ansocp/>
|-
| [[file:sodium symbol (Dalton).svg|24px]] ||⦷||[[wikt:soda|soda]]||[[sodium]]||11|| ||<ref name=dalton1808ansocp/>
|-
| [[file:magnesium symbol (Dalton).svg|24px]] ||⊛||[[wikt:magnesia|magnesia]]||[[magnesium]]||12||alchemical symbol for magnesia||<ref name=dalton1808ansocp/>
|-
| [[file:aluminium symbol (Dalton).svg|24px]] || ||[[wikt:alumine|alumine]]||[[aluminium]]||13||(4 dots)||<ref name=dalton1808ansocp/>
|-
| [[file:silicon symbol (Dalton).svg|24px]] ||🟕||[[silex]]||[[silicon]]||14|| ||<ref name=dalton1810ansocp>{{cite book | last = Dalton | first = John | author-link = John Dalton | date = 1810 | chapter = V: Compounds of two Elements - Section 12: Earths - Explanation of Plates - Plate 5: Elements  | title = A New System of Chemical Philosophy. Part II. | pages = 546–548 | location = [[Manchester]] | publisher = Printed by Russell & Allen for R. Bickerstaff, [[Strand, London]]}}</ref>
|-
| [[file:phosphorus symbol (Dalton).svg|24px]] || ||colspan=2|[[phosphorus]]||15||(3 radii)||<ref name=dalton1808ansocp/>
|-
| [[file:sulphur symbol (Dalton).svg|24px]] ||<span style="color:red">🜨</span>||colspan=2|[[sulphur]]||16|| ||<ref name=dalton1808ansocp/>
|-
| [[file:potassium symbol (Dalton).svg|24px]] || ||[[potash]]||[[potassium]]||19||(3 vertical lines)||<ref name=dalton1808ansocp/>
|-
| [[file:calcium symbol (Dalton).svg|24px]] ||<span style="color:red">⦾</span>||[[Lime (material)|lime]]||[[calcium]]||20||or ◎||<ref name=dalton1808ansocp/>
|-
| [[file:titanium symbol (Dalton).svg|24px]] || ||colspan=2|[[titanium]]|| 22 || (enclosing circle) <small>Tit</small>⃝ ||<ref name=dalton1810ansocp/>
|-
| [[file:manganese symbol (Dalton).svg|24px]] || ||colspan=2|[[manganese]]|| 25 || (enclosing circle) <small>Ma</small>⃝ ||<ref name=dalton1810ansocp/>
|-
| [[file:iron symbol (Dalton).svg|24px]] ||<span style="color:red">Ⓘ</span>||colspan=2|[[iron]]||26|| ||<ref name=dalton1808ansocp/>
|-
| [[file:nickel symbol (Dalton).svg|24px]] ||Ⓝ||colspan=2|[[nickel]]||28|| ||<ref name=dalton1808ansocp/>
|-
| [[file:cobalt symbol (Dalton).svg|24px]] || ||colspan=2|[[cobalt]]|| 27 || (enclosing circle) <small>Cob</small>⃝ ||<ref name=dalton1810ansocp/>
|-
| [[file:copper symbol (Dalton).svg|24px]] ||<span style="color:red">Ⓒ</span>||colspan=2|[[copper]]||29||(black letter in red circle)||<ref name=dalton1808ansocp/>
|-
| [[file:zinc symbol (Dalton).svg|24px]] ||Ⓩ||colspan=2|[[zinc]]||30|| ||<ref name=dalton1808ansocp/>
|-
| [[file:arsenic symbol (Dalton).svg|24px]] || ||colspan=2|[[arsenic]]|| 33 || (enclosing circle) <small>Ar</small>⃝ ||<ref name=dalton1810ansocp/>
|-
| [[file:strontium symbol (Dalton).svg|24px]] || ||[[strontian]]||[[strontium]]||38||(4 ticks)||<ref name=dalton1808ansocp/>
|-
| [[file:yttrium symbol (Dalton).svg|24px]] ||⊕︀︀<!--U+FE00 forces display of white rim-->||[[yttria]]||[[yttrium]]||39||(plus does not touch circle) ||<ref name=dalton1810ansocp/>
|-
| [[file:zirconium symbol (Dalton).svg|24px]] ||  || [[wikt:zircone|zircone]]||[[zirconium]]|| 40 || (vertical zigzag)||<ref name=dalton1810ansocp/>
|-
| [[file:silver symbol (Dalton).svg|24px]] ||Ⓢ||colspan=2|[[silver]]||47|| ||<ref name=dalton1808ansocp/>
|-
| [[file:tin symbol (Dalton).svg|24px]] ||Ⓣ||colspan=2|[[tin]]||50|| ||<ref name=dalton1810ansocp/>
|-
| [[file:antimony symbol (Dalton).svg|24px]] || ||colspan=2|[[antimony]]|| 51 || (enclosing circle) <small>An</small>⃝ ||<ref name=dalton1810ansocp/>
|-
| [[file:barium symbol (Dalton).svg|24px]] || ||[[barytes]]||[[barium]]||56||(6 ticks)||<ref name=dalton1808ansocp/>
|-
| [[file:cerium symbol (Dalton).svg|24px]] || ||colspan=2|[[cerium]]|| 58 || (enclosing circle) <small>Ce</small>⃝ ||<ref name=dalton1810ansocp/>
|-
| [[file:tungsten symbol (Dalton).svg|24px]] || ||colspan=2|[[tungsten]]|| 74 || (enclosing circle) <small>Tu</small>⃝ ||<ref name=dalton1810ansocp/>
|-
| [[file:platinum symbol (Dalton).svg|24px]] ||<span style="color:red">Ⓟ</span>||[[wikt:platina|platina]]||[[platinum]]||78||(black letter in red circle)||<ref name=dalton1808ansocp/>
|-
| [[file:gold symbol (Dalton).svg|24px]] ||Ⓖ||colspan=2|[[gold]]||79|| ||<ref name=dalton1808ansocp/>
|-
| [[file:mercury symbol (Dalton).svg|24px]] || ||colspan=2|[[Mercury (element)|mercury]]||80||(dotted inside perimeter)||<ref name=dalton1808ansocp/>
|-
| [[file:lead symbol (Dalton).svg|24px]] ||Ⓛ||colspan=2|[[lead]]||82|| ||<ref name=dalton1808ansocp/>
|-
| [[file:bismuth symbol (Dalton).svg|24px]] ||Ⓑ||colspan=2|[[bismuth]]||83|| ||<ref name=dalton1810ansocp/>
|-
| [[file:uranium symbol (Dalton).svg|24px]] ||Ⓤ||colspan=2|[[uranium]]||92|| ||<ref name=dalton1810ansocp/>
|}

==Symbols for named isotopes==
The following is a [[table of nuclides|list of isotopes]] which have been given unique symbols. This is not a list of current systematic symbols (in the {{sup|''u''}}Atom form); such a list can instead be found in [[Template:Navbox element isotopes]]. The symbols for [[isotopes of hydrogen]], [[deuterium]] (D) and [[tritium]] (T), are still in use today, as is [[thoron]] (Tn) for radon-220 (though not [[actinon]]; An usually instead means a generic [[actinide]]). [[Heavy water]] and other [[deuterated solvent]]s are commonly used in chemistry, and it is convenient to use a single character rather than a symbol with a subscript in these cases. The practice also continues with tritium compounds. When the name of the solvent is given, a lowercase d is sometimes used. For example, d{{sub|6}}-benzene or C{{sub|6}}D{{sub|6}} can be used instead of C{{sub|6}}[{{sup|2}}H{{sub|6}}].<ref name="SectionH">{{cite web |last1=IUPAC|title=Isotopically Modified Compounds|url=http://www.chem.qmul.ac.uk/iupac/sectionH/|publisher=IUPAC|access-date=31 March 2015|ref=SectionH}}</ref>

The symbols for isotopes of elements other than hydrogen and radon are no longer used in the scientific community. Many of these symbols were designated during the early years of [[radiochemistry]], and several isotopes (namely those in the [[decay chain]]s of [[actinium]], [[radium]], and [[thorium]]) bear [[placeholder name]]s using the early naming system devised by [[Ernest Rutherford]].<ref>{{cite journal |editor-last= Morgan|editor-first= G. T.|date= 1905|title= Annual Reports on the Progress of Chemistry for 1904|journal= Journal of the Chemical Society|publisher= Gurney & Jackson|volume= 1|pages= 268|quote= In view of the extraordinarily complex nature of the later changes occurring in Radium, Rutherford has proposed a new and convenient system of nomenclature. The first product of the change of the radium emanation is named radium A, the next radium B, and so on.}}</ref>
{{sticky header}}
{| class="wikitable sortable sticky-header" style
!Symbol!!Name!!Atomic<br/>number!!class="unsortable"|Origin of symbol
|-
|Ac||[[Actinium]]||89||From Greek ''[[ray (optics)|aktinos]]''. Name restricted at one time to {{sup|227}}Ac, an isotope of [[actinium]]. This named isotope later became the official name for element 89.
|-
|AcA||Actinium A||84||From [[actinium]] and A. Placeholder name given at one time to {{sup|215}}Po, an isotope of [[polonium]] identified in the decay chain of actinium.
|-
|AcB||Actinium B||82||From actinium and B. Placeholder name given at one time to {{sup|211}}Pb, an isotope of [[lead]] identified in the decay chain of actinium.
|-
|AcC||Actinium C||83||From actinium and C. Placeholder name given at one time to {{sup|211}}Bi, an isotope of [[bismuth]] identified in the decay chain of actinium.
|-
|AcC′||Actinium C′||84||From actinium and C[[prime (symbol)|′]]. Placeholder name given at one time to {{sup|211}}Po, an isotope of [[polonium]] identified in the decay chain of [[actinium]].
|-
|AcC″||Actinium C″||81||From actinium and C[[double prime|″]]. Placeholder name given at one time to <sup>207</sup>Tl, an isotope of [[thallium]] identified in the decay chain of [[actinium]].
|-
|AcK||Actinium K||87||Name given at one time to <sup>223</sup>Fr, an isotope of [[francium]] identified in the decay chain of [[actinium]].
|-
|AcU||Actino-uranium||92||Name given at one time to <sup>235</sup>U, an isotope of [[uranium]].
|-
|AcX||Actinium X||88||Name given at one time to <sup>223</sup>Ra, an isotope of [[radium]] identified in the decay chain of [[actinium]].
|-
|An||[[Actinon]]||86||From ''actin''ium and [[emanation (chemistry)|emanati''on'']]. Name given at one time to <sup>219</sup>Rn, an isotope of [[radon]] identified in the decay chain of [[actinium]].
|-
|D||[[Deuterium]]||1||From the Greek ''[[2 (number)|deuteros]]''. Name given to <sup>2</sup>H.
|-
|Io||[[Ionium]]||90||Name given to <sup>230</sup>Th, an isotope of [[thorium]] identified in the decay chain of [[uranium]].
|-
|MsTh<sub>1</sub>||Mesothorium 1||88||Name given at one time to <sup>228</sup>Ra, an isotope of [[radium]].
|-
|MsTh<sub>2</sub>||Mesothorium 2||89||Name given at one time to <sup>228</sup>Ac, an isotope of [[actinium]].
|-
|Pa||[[Protactinium]]||91||From the Greek ''protos'' and [[actinium]]. Name restricted at one time to <sup>231</sup>Pa, an isotope of [[protactinium]]. This named isotope later became the official name for [[protactinium|element 91]].
|-
|Ra||[[Radium]]||88||From the Latin ''[[ray (optics)|radius]]''. Name restricted at one time to <sup>226</sup>Ra, an isotope of [[radium]]. This named isotope later became the official name for [[radium|element 88]].
|-
|RaA||[[Polonium-218|Radium A]]||84||From [[radium]] and A. Placeholder name given at one time to <sup>218</sup>Po, an isotope of [[polonium]] identified in the decay chain of [[radium]].
|-
|RaB||Radium B||82||From radium and B. Placeholder name given at one time to <sup>214</sup>Pb, an isotope of [[lead]] identified in the decay chain of [[radium]].
|-
|RaC||Radium C||83||From radium and C. Placeholder name given at one time to <sup>214</sup>Bi, an isotope of [[bismuth]] identified in the decay chain of [[radium]].
|-
|RaC′||Radium C′||84||From radium and C[[prime (symbol)|′]]. Placeholder name given at one time to <sup>214</sup>Po, an isotope of [[polonium]] identified in the decay chain of [[radium]].
|-
|RaC″||Radium C″||81||From radium and C[[double prime|″]]. Placeholder name given at one time to <sup>210</sup>Tl, an isotope of [[thallium]] identified in the decay chain of [[radium]].
|-
|RaD||Radium D||82||From radium and D. Placeholder name given at one time to <sup>210</sup>Pb, an isotope of [[lead]] identified in the decay chain of [[radium]].
|-
|RaE||Radium E||83||From radium and E. Placeholder name given at one time to <sup>210</sup>Bi, an isotope of [[bismuth]] identified in the decay chain of [[radium]].
|-
|RaE″||Radium E″||81||From radium and E[[double prime|″]]. Placeholder name given at one time to <sup>206</sup>Tl, an isotope of [[thallium]] identified in the decay chain of [[radium]].
|-
|RaF||[[Polonium-210|Radium F]]||84||From radium and F. Placeholder name given at one time to <sup>210</sup>Po, an isotope of [[polonium]] identified in the decay chain of radium.
|-
|RdAc||Radioactinium||90||Name given at one time to <sup>227</sup>Th, an isotope of [[thorium]].
|-
|RdTh||Radiothorium||90||Name given at one time to <sup>228</sup>Th, an isotope of [[thorium]].
|-
|Rn||[[Radon]]||86||From ''rad''ium and [[emanation (chemistry)|emanati''on'']]. Name restricted at one time to <sup>222</sup>Rn, an isotope of [[radon]] identified in the decay chain of [[radium]]. This named isotope later became the official name for [[radon|element 86]] in 1923.
|-
|T||[[Tritium]]||1||From the Greek ''[[3 (number)|tritos]]''. Name given to <sup>3</sup>H.
|-
|Th||[[Thorium]]||90||After [[Thor]]. Name restricted at one time to <sup>232</sup>Th, an isotope of [[thorium]]. This named isotope later became the official name for [[thorium|element 90]].
|-
|ThA||Thorium A||84||From [[thorium]] and A. Placeholder name given at one time to <sup>216</sup>Po, an isotope of [[polonium]] identified in the decay chain of [[thorium]].
|-
|ThB||Thorium B||82||From thorium and B. Placeholder name given at one time to <sup>212</sup>Pb, an isotope of [[lead]] identified in the decay chain of [[thorium]].
|-
|ThC||Thorium C||83||From thorium and C. Placeholder name given at one time to <sup>212</sup>Bi, an isotope of [[bismuth]] identified in the decay chain of [[thorium]].
|-
|ThC′||Thorium C′||84||From thorium and C[[prime (symbol)|′]]. Placeholder name given at one time to <sup>212</sup>Po, an isotope of [[polonium]] identified in the decay chain of [[thorium]].
|-
|ThC″||Thorium C″||81||From thorium and C[[double prime|″]]. Placeholder name given at one time to <sup>208</sup>Tl, an isotope of [[thallium]] identified in the decay chain of [[thorium]].
|-
|ThX||Thorium X||88||Name given at one time to <sup>224</sup>Ra, an isotope of [[radium]] identified in the decay chain of [[thorium]].
|-
|Tn||[[Thoron]]||86||From ''thor''ium and [[emanation (chemistry)|emanati''on'']]. Name given to <sup>220</sup>Rn, an isotope of [[radon]] identified in the decay chain of [[thorium]].
|-
|UI||[[uranium-238|Uranium I]]||92||Name given at one time to <sup>238</sup>U, an isotope of [[uranium]].
|-
|UII||[[uranium-234|Uranium II]]||92||Name given at one time to <sup>234</sup>U, an isotope of [[uranium]].
|-
|UX<sub>1</sub>||Uranium X<sub>1</sub>||90||Name given at one time to <sup>234</sup>Th, an isotope of [[thorium]] identified in the decay chain of [[uranium]].
|-
|UX<sub>2</sub>||Uranium X<sub>2</sub>||91||Name given at one time to <sup>234m</sup>Pa, an isotope of [[protactinium]] identified in the decay chain of uranium.
|-
|UY||Uranium Y||90||Name given at one time to <sup>231</sup>Th, an isotope of [[thorium]] identified in the decay chain of uranium.
|-
|UZ||Uranium Z||91||Name given at one time to <sup>234</sup>Pa, an isotope of [[protactinium]] identified in the decay chain of uranium.
|}

==Other symbols==
{{See also|Skeletal formula#Pseudoelement symbols}}
* In [[Chinese language|Chinese]], each chemical element has a dedicated [[Chinese character|character]], usually created for the purpose (see [[Chemical elements in East Asian languages]]). However, in Chinese Latin symbols are also used, especially in formulas.

General:
{{Div col|colwidth=30em}}
*A: A deprotonated [[acid]] or an [[anion]]
*An: any [[actinide]]
*B: A [[base (chemistry)|base]], often in the context of [[Lewis acid–base theory]] or [[Brønsted–Lowry acid–base theory]]
*E: any element or [[electrophile]]
*L: any [[ligand]]
*Ln: any [[lanthanide]]
*M: any [[metal]]
*Mm: [[mischmetal]] (occasionally used)<ref>{{cite journal |last1=Jurczyk|first1=M.|last2=Rajewski|first2=W.|last3=Majchrzycki|first3=W.|last4=Wójcik|first4=G.|date=1999-08-30|title=Mechanically alloyed MmNi<sub>5</sub>-type materials for metal hydride electrodes|journal=Journal of Alloys and Compounds|volume=290|issue=1–2|pages=262–266|doi=10.1016/S0925-8388(99)00202-9}}</ref>
*Ng: any [[noble gas]] (Rg is sometimes used, but that is also used for the element [[roentgenium]]: see above)
*Nu: any [[nucleophile]]
*R: any unspecified radical ([[moiety (chemistry)|moiety]]) not important to the discussion
*St: [[steel]] (occasionally used)
*X: any [[halogen]] (or sometimes [[pseudohalogen]])
{{Div col end}}
From organic chemistry:
{{Div col|colwidth=30em}}
*Ac: [[acetyl]] – (also used for the element [[actinium]]: see above)
*Ad: 1-[[adamantyl]]
*All: [[allyl]]
*Am: amyl ([[pentyl]]) – (also used for the element [[americium]]: see above)
*Ar: [[aryl]] – (also used for the element [[argon]]: see above)
*Bn: [[benzyl]]
*Bs: [[brosyl]] or (outdated) benzenesulfonyl
*Bu: [[butyl]] (''i''-, ''s''-, or ''t''- prefixes may be used to denote ''iso''-, ''sec''-, or ''tert''- isomers, respectively)
*Bz: [[benzoyl]]
*Cp: [[cyclopentadienyl]]
*Cp*: [[pentamethylcyclopentadiene|pentamethylcyclopentadienyl]]
*Cy: [[cyclohexyl]]
*Cyp: [[cyclopentyl]]
*Et: [[ethyl group|ethyl]]
*Me: [[methyl]]
*Mes: [[Mesitylene|mesityl]] (2,4,6-trimethylphenyl)
*Ms: [[mesyl]] (methylsulfonyl)
*Np: [[neopentyl]] – (also used for the element [[neptunium]]: see above)
*Ns: [[nosyl]]
*Pent: [[pentyl]]
*Ph, [[phi (letter)|Φ]]: [[phenyl]]
*Pr: [[propyl]] – (''i''- prefix may be used to denote isopropyl. Also used for the element [[praseodymium]]: see above)
*R: In organic chemistry contexts, an unspecified "R" is often understood to be an [[alkyl]] group
*Tf: [[triflyl]] (trifluoromethanesulfonyl)
*Tr, Trt: [[trityl]] (triphenylmethyl)
*Ts, Tos: [[tosyl]] (''para''-toluenesulfonyl) – (Ts also used for the element [[tennessine]]: see above)
*Vi: [[vinyl group|vinyl]]
{{Div col end}}

Exotic atoms:
{{Div col|colwidth=30em}}
*Mu: [[muonium]]
*Pn: [[protonium]]
*Ps: [[positronium]]
{{Div col end}}

[[Hazard symbol|Hazard pictographs]] are another type of symbols used in chemistry.

==See also==
*[[List of chemical elements naming controversies]]
*[[List of elements]]
*[[Nuclear notation]]

==Notes==
{{Reflist|group=nb}}

==References==
{{Reflist}}
*[https://elements.vanderkrogt.net/ Elementymology & Elements Multidict], element name etymologies. Retrieved July 15, 2005.
*Atomic Weights of the Elements 2001, [http://www.iupac.org/publications/pac/2003/7508/7508x1107.html Pure Appl. Chem. 75(8), 1107–1122, 2003]. Retrieved June 30, 2005. Atomic weights of elements with atomic numbers from 1–109 taken from this source.
*[http://www.iupac.org/news/archives/2005/atomic-weights_revised05.html IUPAC Standard Atomic Weights Revised] {{Webarchive|url=https://web.archive.org/web/20080305062433/http://www.iupac.org/news/archives/2005/atomic-weights_revised05.html |date=2008-03-05 }} (2005).
*[https://www.webelements.com/ WebElements Periodic Table]. Retrieved June 30, 2005. Atomic weights of elements with atomic numbers 110–116 taken from this source.
*Leighton, Robert B. ''Principles of Modern Physics''. New York: McGraw-Hill. 1959.
*Scerri, E.R. "The Periodic Table, Its Story and Its Significance". New York, Oxford University Press. 2007.

==External links==
{{Commons category}}
*[http://web.lemoyne.edu/~giunta/berzelius.html Berzelius' List of Elements]
*[http://www.iupac.org/reports/1998/7001coplen/history.pdf History of IUPAC Atomic Weight Values (1883 to 1997)]
*[https://www.acs.org/content/acs/en/about/governance/committees/nomenclature.html Committee on Nomenclature, Terminology, and Symbols] {{Webarchive|url=https://web.archive.org/web/20201204013636/https://www.acs.org/content/acs/en/about/governance/committees/nomenclature.html |date=2020-12-04 }}, American Chemical Society

{{Navbox periodic table}}
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[[Category:Symbols|Chemistry]]
[[Category:Chemical elements|*]]

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