Editing Chemical symbol (section)

==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/>
|}