Symbol (chemistry)

In chemistry, a symbol is an abbreviation for a chemical element. Symbols for chemical elements normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.

Earlier symbols for chemical elements stem from classical Latin and 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 (hydrargyrum in Greek); and He is the symbol for helium (a new 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 3-letter 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 its atomic number being 8 greater than 100. There are also some historical symbols that are no longer officially used.

In addition to the letters for the element itself, additional details may be added to the symbol as superscripts or subscripts a particular isotope, ionization or oxidation state, or other atomic detail.[1] 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., 14N). 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., 99mTc). Alternately, the number here can represent a specific spin state (e.g., 1O2). 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., 64Gd). 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 Ca2+).
  • The number of atoms of an element in a molecule or chemical compound is shown in the right subscript position (e.g., N2 or Fe2O3). If this number is one, it is normally omitted - the number one is implicitly understood if unspecified.
  • A radical is indicated by a dot on the right side (e.g., Cl 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 structures.

In Chinese, each chemical element has a dedicated character, usually created for the purpose (see Chemical elements in East Asian languages). However, Latin symbols are also used, especially in formulas.

Many functional groups 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 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.

Hazard pictographs are another type of symbols used in chemistry.

Symbols for chemical elements

List of chemical elements
Z[upper-roman 1] Symbol Element Origin of name[2][3] Group Period Atomic weight[4][5] (u (±))
 
1HHydrogenGreek elements hydro- and -gen, meaning 'water-forming'111.008[upper-roman 2][upper-roman 3][upper-roman 4][upper-roman 5]
2HeHeliumGreek hḗlios, 'sun'1814.002602(2)[upper-roman 2][upper-roman 4]
3LiLithiumGreek líthos, 'stone'126.94[upper-roman 2][upper-roman 3][upper-roman 4][upper-roman 6][upper-roman 5]
4BeBerylliumberyl, a mineral (ultimately from the name of Belur in southern India)229.0121831(5)
5BBoronborax, a mineral (from Arabic bawraq)13210.81[upper-roman 2][upper-roman 3][upper-roman 4][upper-roman 5]
6CCarbonLatin carbo, 'coal'14212.011[upper-roman 2][upper-roman 4][upper-roman 5]
7NNitrogenGreek nítron and -gen, meaning 'niter-forming'15214.007[upper-roman 2][upper-roman 4][upper-roman 5]
8OOxygenGreek oxy- and -gen, meaning 'acid-forming'16215.999[upper-roman 2][upper-roman 4][upper-roman 5]
9FFluorineLatin fluere, 'to flow'17218.998403163(6)
10NeNeonGreek néon, 'new'18220.1797(6)[upper-roman 2][upper-roman 3]
11NaSodiumEnglish soda (the symbol Na is derived from New Latin natrium, coined from German Natron, 'natron')1322.98976928(2)
12MgMagnesiumMagnesia, a district of Eastern Thessaly in Greece2324.305[upper-roman 5]
13AlAluminiumalumina, from Latin alumen (gen. aluminis), 'bitter salt, alum'13326.9815384(3)
14SiSiliconLatin silex, 'flint' (originally silicium)14328.085[upper-roman 4][upper-roman 5]
15PPhosphorusGreek phōsphóros, 'light-bearing'15330.973761998(5)
16SSulfurLatin sulphur, 'brimstone'16332.06[upper-roman 2][upper-roman 4][upper-roman 5]
17ClChlorineGreek chlōrós, 'greenish yellow'17335.45[upper-roman 2][upper-roman 3][upper-roman 4][upper-roman 5]
18ArArgonGreek argós, 'idle' (because of its inertness)18339.948[upper-roman 2][upper-roman 4][upper-roman 5]
19KPotassiumNew Latin potassa, 'potash' (the symbol K is derived from Latin kalium)1439.0983(1)
20CaCalciumLatin calx, 'lime'2440.078(4)[upper-roman 2]
21ScScandiumLatin Scandia, 'Scandinavia'3444.955908(5)
22TiTitaniumTitans, the sons of the Earth goddess of Greek mythology4447.867(1)
23VVanadiumVanadis, an Old Norse name for the Scandinavian goddess Freyja5450.9415(1)
24CrChromiumGreek chróma, 'colour'6451.9961(6)
25MnManganesecorrupted from magnesia negra; see Magnesium7454.938043(2)
26FeIronEnglish word (the symbol Fe is derived from Latin ferrum)8455.845(2)
27CoCobaltGerman Kobold, 'goblin'9458.933194(3)
28NiNickelNickel, a mischievous sprite of German miner mythology10458.6934(4)
29CuCopperEnglish word, from Latin cuprum, from Ancient Greek Kýpros 'Cyprus'11463.546(3)[upper-roman 4]
30ZnZincMost likely from German Zinke, 'prong' or 'tooth', though some suggest Persian sang, 'stone'12465.38(2)
31GaGalliumLatin Gallia, 'France'13469.723(1)
32GeGermaniumLatin Germania, 'Germany'14472.630(8)
33AsArsenicFrench arsenic, from Greek arsenikón 'yellow arsenic' (influenced by arsenikós, 'masculine' or 'virile'), from a West Asian wanderword ultimately from Old Iranian *zarniya-ka, 'golden'15474.921595(6)
34SeSeleniumGreek selḗnē, 'moon'16478.971(8)[upper-roman 4]
35BrBromineGreek brômos, 'stench'17479.904[upper-roman 5]
36KrKryptonGreek kryptós, 'hidden'18483.798(2)[upper-roman 2][upper-roman 3]
37RbRubidiumLatin rubidus, 'deep red'1585.4678(3)[upper-roman 2]
38SrStrontiumStrontian, a village in Scotland2587.62(1)[upper-roman 2][upper-roman 4]
39YYttriumYtterby, a village in Sweden3588.90584(1)
40ZrZirconiumzircon, a mineral4591.224(2)[upper-roman 2]
41NbNiobiumNiobe, daughter of king Tantalus from Greek mythology5592.90637(1)
42MoMolybdenumGreek molýbdaina, 'piece of lead', from mólybdos, 'lead'6595.95(1)[upper-roman 2]
43TcTechnetiumGreek tekhnētós, 'artificial'75[98][upper-roman 7]
44RuRutheniumNew Latin Ruthenia, 'Russia'85101.07(2)[upper-roman 2]
45RhRhodiumGreek rhodóeis, 'rose-coloured', from rhódon, 'rose'95102.90549(2)
46PdPalladiumthe asteroid Pallas, considered a planet at the time105106.42(1)[upper-roman 2]
47AgSilverEnglish word (The symbol derives from Latin argentum)115107.8682(2)[upper-roman 2]
48CdCadmiumNew Latin cadmia, from King Kadmos125112.414(4)[upper-roman 2]
49InIndiumLatin indicum, 'indigo' (colour found in its spectrum)135114.818(1)
50SnTinEnglish word (The symbol derives from Latin stannum)145118.710(7)[upper-roman 2]
51SbAntimonyLatin antimonium, the origin of which is uncertain: folk etymologies suggest it is derived from Greek antí ('against') + mónos ('alone'), or Old French anti-moine, 'Monk's bane', but it could plausibly be from or related to Arabic ʾiṯmid, 'antimony', reformatted as a Latin word. (The symbol derives from Latin stibium 'stibnite'.)155121.760(1)[upper-roman 2]
52TeTelluriumLatin tellus, 'the ground, earth'165127.60(3)[upper-roman 2]
53IIodineFrench iode, from Greek ioeidḗs, 'violet')175126.90447(3)
54XeXenonGreek xénon, neuter form of xénos 'strange'185131.293(6)[upper-roman 2][upper-roman 3]
55CsCaesiumLatin caesius, 'sky-blue'16132.90545196(6)
56BaBariumGreek barýs, 'heavy'26137.327(7)
57LaLanthanumGreek lanthánein, 'to lie hidden'36138.90547(7)[upper-roman 2]
58CeCeriumthe dwarf planet Ceres, considered a planet at the time6140.116(1)[upper-roman 2]
59PrPraseodymiumGreek prásios dídymos, 'green twin'6140.90766(1)
60NdNeodymiumGreek néos dídymos, 'new twin'6144.242(3)[upper-roman 2]
61PmPromethiumPrometheus of Greek mythology6[145][upper-roman 7]
62SmSamariumsamarskite, a mineral named after Colonel Vasili Samarsky-Bykhovets, Russian mine official6150.36(2)[upper-roman 2]
63EuEuropiumEurope6151.964(1)[upper-roman 2]
64GdGadoliniumgadolinite, a mineral named after Johan Gadolin, Finnish chemist, physicist and mineralogist6157.25(3)[upper-roman 2]
65TbTerbiumYtterby, a village in Sweden6158.925354(8)
66DyDysprosiumGreek dysprósitos, 'hard to get'6162.500(1)[upper-roman 2]
67HoHolmiumNew Latin Holmia, 'Stockholm'6164.930328(7)
68ErErbiumYtterby, a village in Sweden6167.259(3)[upper-roman 2]
69TmThuliumThule, the ancient name for an unclear northern location6168.934218(6)
70YbYtterbiumYtterby, a village in Sweden6173.045(10)[upper-roman 2]
71LuLutetiumLatin Lutetia, 'Paris'6174.9668(1)[upper-roman 2]
72HfHafniumNew Latin Hafnia, 'Copenhagen' (from Danish havn)46178.49(2)
73TaTantalumKing Tantalus, father of Niobe from Greek mythology56180.94788(2)
74WTungstenSwedish tung sten, 'heavy stone' (The symbol is from wolfram, the old name of the tungsten mineral wolframite)66183.84(1)
75ReRheniumLatin Rhenus, 'the Rhine'76186.207(1)
76OsOsmiumGreek osmḗ, 'smell'86190.23(3)[upper-roman 2]
77IrIridiumIris, the Greek goddess of the rainbow96192.217(2)
78PtPlatinumSpanish platina, 'little silver', from plata 'silver'106195.084(9)
79AuGoldEnglish word (The symbol derives from Latin aurum)116196.966570(4)
80HgMercuryMercury, Roman god of commerce, communication, and luck, known for his speed and mobility (The symbol is from the element's Latin name hydrargyrum, derived from Greek hydrárgyros, 'water-silver')126200.592(3)
81TlThalliumGreek thallós, 'green shoot or twig'136204.38[upper-roman 5]
82PbLeadEnglish word (The symbol derives from Latin plumbum)146207.2(1)[upper-roman 2][upper-roman 4]
83BiBismuthGerman Wismut, from weiß Masse 'white mass', unless from Arabic156208.98040(1)[upper-roman 7]
84PoPoloniumLatin Polonia, 'Poland' (the home country of Marie Curie)166[209][upper-roman 7]
85AtAstatineGreek ástatos, 'unstable'176[210][upper-roman 7]
86RnRadonradium186[222][upper-roman 7]
87FrFranciumFrance17[223][upper-roman 7]
88RaRadiumFrench radium, from Latin radius, 'ray'27[226][upper-roman 7]
89AcActiniumGreek aktís, 'ray'37[227][upper-roman 7]
90ThThoriumThor, the Scandinavian god of thunder7232.0377(4)[upper-roman 7][upper-roman 2]
91PaProtactiniumproto- (from Greek prôtos, 'first, before') + actinium, which is produced through the radioactive decay of protactinium7231.03588(1)[upper-roman 7]
92UUraniumUranus, the seventh planet in the Solar System7238.02891(3)[upper-roman 7]
93NpNeptuniumNeptune, the eighth planet in the Solar System7[237][upper-roman 7]
94PuPlutoniumthe dwarf planet Pluto, considered the ninth planet in the Solar System at the time7[244][upper-roman 7]
95AmAmericiumThe Americas, as the element was first synthesised on the continent, by analogy with europium7[243][upper-roman 7]
96CmCuriumPierre Curie and Marie Curie, French physicists and chemists7[247][upper-roman 7]
97BkBerkeliumBerkeley, California, where the element was first synthesised, by analogy with terbium7[247][upper-roman 7]
98CfCaliforniumCalifornia, where the element was first synthesised7[251][upper-roman 7]
99EsEinsteiniumAlbert Einstein, German physicist7[252][upper-roman 7]
100FmFermiumEnrico Fermi, Italian physicist7[257][upper-roman 7]
101MdMendeleviumDmitri Mendeleev, Russian chemist and inventor who proposed the periodic table7[258][upper-roman 7]
102NoNobeliumAlfred Nobel, Swedish chemist and engineer7[259][upper-roman 7]
103LrLawrenciumErnest O. Lawrence, American physicist7[266][upper-roman 7]
104RfRutherfordiumErnest Rutherford, British chemist and physicist47[267][upper-roman 7]
105DbDubniumDubna, Russia, where the Joint Institute for Nuclear Research is located57[268][upper-roman 7]
106SgSeaborgiumGlenn T. Seaborg, American chemist67[269][upper-roman 7]
107BhBohriumNiels Bohr, Danish physicist77[270][upper-roman 7]
108HsHassiumNew Latin Hassia, 'Hesse' (a state in Germany)87[270][upper-roman 7]
109MtMeitneriumLise Meitner, Austrian physicist97[278][upper-roman 7]
110DsDarmstadtiumDarmstadt, Germany, where the element was first synthesised107[281][upper-roman 7]
111RgRoentgeniumWilhelm Conrad Röntgen, German physicist117[282][upper-roman 7]
112CnCoperniciumNicolaus Copernicus, Polish astronomer127[285][upper-roman 7]
113NhNihoniumJapanese Nihon, 'Japan' (where the element was first synthesised)137[286][upper-roman 7]
114FlFleroviumFlerov Laboratory of Nuclear Reactions, part of JINR, where the element was synthesised; itself named after Georgy Flyorov, Russian physicist147[289][upper-roman 7]
115McMoscoviumMoscow Oblast, Russia, where the element was first synthesised157[290][upper-roman 7]
116LvLivermoriumLawrence Livermore National Laboratory in Livermore, California, which collaborated with JINR on its synthesis167[293][upper-roman 7]
117TsTennessineTennessee, United States177[294][upper-roman 7]
118OgOganessonYuri Oganessian, Russian physicist187[294][upper-roman 7]

Notes

  1. Z is the standard symbol for atomic number
  2. The isotopic composition of this element varies in some geological specimens, and the variation may exceed the uncertainty stated in the table.
  3. The isotopic composition of the element can vary in commercial materials, which can cause the atomic weight to deviate significantly from the given value.
  4. The isotopic composition varies in terrestrial material such that a more precise atomic weight can not be given.
  5. The value listed is the conventional atomic-weight value suitable for trade and commerce. The actual value may differ depending on the isotopic composition of the sample. Since 2009, IUPAC provides the standard atomic-weight values for these elements using the interval notation. The corresponding standard atomic weights are:
    • Hydrogen: [1.00784, 1.00811]
    • Lithium: [6.938, 6.997]
    • Boron: [10.806, 10.821]
    • Carbon: [12.0096, 12.0116]
    • Nitrogen: [14.00643, 14.00728]
    • Oxygen: [15.99903, 15.99977]
    • Magnesium: [24.304, 24.307]
    • Silicon: [28.084, 28.086]
    • Sulfur: [32.059, 32.076]
    • Chlorine: [35.446, 35.457]
    • Argon: [39.792, 39.963]
    • Bromine: [79.901, 79.907]
    • Thallium: [204.382, 204.385]
  6. The atomic weight of commercial lithium can vary between 6.939 and 6.996—analysis of the specific material is necessary to find a more accurate value.
  7. The element does not have any stable nuclides, and a value in brackets, e.g. [209], indicates the mass number of the longest-lived isotope of the element. However, four such elements, bismuth, thorium, protactinium, and uranium, have characteristic terrestrial isotopic compositions, and thus their standard atomic weights are given.

Antimatter atoms are denoted by a bar above the symbol for their matter counterpart, so e.g. H is the symbol for antihydrogen.

Symbols and names not currently used

The following is a list of symbols and names formerly used or suggested for elements, including symbols for placeholder names and names given by discredited claimants for discovery.

Chemical symbolNameAtomic numberOrigin of symbolWhy not usedRefs
AArgon18A used for Argon until 1957. Current symbol is Ar.[nb 1][6]
AbAlabamine85Discredited claim to discovery of astatine.[nb 2][7][8]
AdAldebaranium70Former name for ytterbium.[nb 2]
AmAlabamine85Discredited claim to discovery of astatine. The symbol is now used for americium.[nb 2][7][8]
AnAthenium99Proposed name for einsteinium.[nb 3]
AoAusonium93Discredited claim to discovery of neptunium.[nb 2][7]
AzAzote7Former name for nitrogen.[nb 1]
BoBoron5Current symbol is B.[nb 1]
BvBrevium91Former name for protactinium.[nb 1]
BzBerzelium90Baskerville wrongly believed berzelium to be a new element. Was actually thorium.[nb 3][9]
CbColumbium41Former name for niobium.[nb 1][7][9]
ChChromium24Current symbol is Cr.[nb 1]
ClColumbium41Former name for niobium. The symbol is now used for chlorine.[nb 1]
CnCarolinium90Baskerville wrongly believed carolinium to be a new element. Was actually thorium. The symbol is now used for copernicium.[9]
CpCassiopeium71Former name for lutetium.[nb 1]
CpCopernicium112Current symbol is Cn.[nb 1]
CtCeltium72Discredited claim to discovery of hafnium.[nb 2]
CtCenturium100Proposed name for fermium.[nb 3]
DDidymium59/60Mixture of the elements praseodymium and neodymium. Mosander wrongly believed didymium to be an element.[10]
DaDavyum43Discredited claim to discovery of technetium.[nb 2][7]
DbDubnium104Proposed name for rutherfordium. The symbol and name were instead used for element 105.[nb 1][nb 3][7]
DiDidymium59/60Mixture of the elements praseodymium and neodymium. Mosander wrongly believed didymium to be an element.[10]
DsDysprosium66Current symbol is Dy. The symbol is now used for darmstadtium.[nb 1]
EEinsteinium99Current symbol is Es.[nb 1]
EErbium68Current symbol is Er.[nb 1]
EaEkaaluminium31Name given by Mendeleev to an as of then undiscovered element. When discovered, gallium closely matched the prediction.[nb 3][nb 4]
EbEkaboron21Name given by Mendeleev to an as of then undiscovered element. When discovered, scandium closely matched the prediction.[nb 3][nb 4][7]
ElEkaaluminium31Name given by Mendeleev to an as of then undiscovered element. When discovered, gallium closely matched the prediction.[nb 3][nb 4][7]
EmEkamanganese43Name given by Mendeleev to an as of then undiscovered element. When discovered, technetium closely matched the prediction.[nb 3][nb 4][7]
EmEmanation86Also called "radium emanation", the name was originally given by Friedrich Ernst Dorn in 1900. In 1923, this element officially became radon (the name given at one time to 222Rn, an isotope identified in the decay chain of radium).[nb 1][7]
EmEmanium89Alternate name formerly proposed for actinium.[nb 3]
EsEkasilicon32Name given by Mendeleev to an as of then undiscovered element. When discovered, germanium closely matched the prediction. The symbol is now used for einsteinium.[nb 3][nb 4][7]
EsEsperium94Discredited claim to discovery of plutonium. The symbol is now used for einsteinium.[nb 2][7]
FaFrancium87Current symbol is Fr.[nb 1]
FlFlorentium61Discredited claim to discovery of promethium. The symbol is now used for flerovium.[nb 2]
FlFluorine9Current symbol is F. The symbol is now used for flerovium.[nb 1]
FrFlorentium61Discredited claim to discovery of promethium. The symbol is now used for francium.[nb 2][7]
GGlucinium4Former name for beryllium.[nb 1]
GlGlucinium4Former name for beryllium.[nb 1][7]
HaHahnium105Proposed name for dubnium.[nb 3]
HnHahnium108Proposed name for hassium.[nb 3][7]
HvHelvetium85Discredited claim to discovery of astatine.[nb 2][9]
HyMercury80Hy from the Greek hydrargyrum for "liquid silver". Current symbol is Hg.[nb 1][6]
IIridium77Current symbol is Ir. The symbol is now used for iodine.[nb 1]
IlIllinium61Discredited claim to discovery of promethium.[nb 2][7]
JJodium53Former name for iodine.[nb 1]
JgJargonium72Discredited claim to discovery of hafnium.[nb 2][7]
JlJoliotium105Proposed name for dubnium.[nb 3][7]
KaPotassium19Current symbol is K.[nb 1]
KuKurchatovium104Proposed name for rutherfordium.[nb 3][7]
LLithium3Current symbol is Li.[nb 1]
LwLawrencium103Current symbol is Lr.[nb 1]
MMuriaticum17Former name for chlorine.[nb 1]
MaManganese25Current symbol is Mn.[nb 1]
MaMasurium43Disputed claim to discovery of technetium.[nb 2][7]
MdMendelevium97Proposed name for berkelium. The symbol and name were later used for element 101.[nb 1][nb 3]
MlMoldavium87Discredited claim to discovery of francium.[nb 2][9]
MsMagnesium12Current symbol is Mg.[nb 1]
MsMasurium43Disputed claim to discovery of technetium.[nb 2]
MvMendelevium101Current symbol is Md.[nb 1]
NgNorwegium72Discredited claim to discovery of hafnium.[nb 2]
NoNorium72Discredited claim to discovery of hafnium. The symbol is now used for nobelium.[nb 2]
NpNipponium43Discredited claim to discovery of technetium. The symbol is now used for neptunium.[nb 2][7]
NsNielsbohrium105Proposed name for dubnium.[nb 3][7]
NsNielsbohrium107Proposed name for bohrium.[nb 3][7]
NtNiton86Former name for radon.[nb 1][7]
NyNeoytterbium70Former name for ytterbium.[nb 1]
PLead82Current symbol is Pb. The symbol is now used for phosphorus.[nb 1]
PaPalladium46Current symbol is Pd. The symbol is now used for protactinium.[nb 1]
PePelopium41Former name for niobium.[nb 1]
PlPalladium46Current symbol is Pd.[nb 1]
PoPotassium19Current symbol is K. The symbol is now used for polonium.[nb 1]
RRhodium45Current symbol is Rh.[nb 1]
RdRadium88Current symbol is Ra.[nb 1]
RfRutherfordium106Proposed name for seaborgium. The symbol and name were instead used for element 104.[nb 1][nb 3][7]
RoRhodium45Current symbol is Rh.[nb 1]
SaSamarium62Current symbol is Sm.[nb 1][7]
SoSodium11Current symbol is Na.[nb 1]
StAntimony51Current symbol is Sb.[nb 1]
StTin50Current symbol is Sn.[nb 1]
TnTungsten74Current symbol is W.[nb 1]
TrTerbium65Current symbol is Tb.[nb 1]
TuThulium69Current symbol is Tm.[nb 1]
TuTungsten74Current symbol is W.[nb 1]
UnbUnnilbium102Temporary name given to nobelium until it was permanently named by IUPAC.[nb 4]
UneUnnilennium109Temporary name given to meitnerium until it was permanently named by IUPAC.[nb 4]
UnhUnnilhexium106Temporary name given to seaborgium until it was permanently named by IUPAC.[nb 4]
UnoUnniloctium108Temporary name given to hassium until it was permanently named by IUPAC.[nb 4]
UnpUnnilpentium105Temporary name given to dubnium until it was permanently named by IUPAC.[nb 4]
UnqUnnilquadium104Temporary name given to rutherfordium until it was permanently named by IUPAC.[nb 4]
UnsUnnilseptium107Temporary name given to bohrium until it was permanently named by IUPAC.[nb 4]
UntUnniltrium103Temporary name given to lawrencium until it was permanently named by IUPAC.[nb 4]
UnuUnnilunium101Temporary name given to mendelevium until it was permanently named by IUPAC.[nb 4]
UubUnunbium112Temporary name given to copernicium until it was permanently named by IUPAC.[nb 4]
UuhUnunhexium116Temporary name given to livermorium until it was permanently named by IUPAC.[nb 4]
UunUnunnilium110Temporary name given to darmstadtium until it was permanently named by IUPAC.[nb 4]
UuoUnunoctium118Temporary name given to oganesson until it was permanently named by IUPAC.[nb 4]
UupUnunpentium115Temporary name given to moscovium until it was permanently named by IUPAC.[nb 4]
UuqUnunquadium114Temporary name given to flerovium until it was permanently named by IUPAC.[nb 4]
UusUnunseptium117Temporary name given to tennessine until it was permanently named by IUPAC.[nb 4]
UutUnuntrium113Temporary name given to nihonium until it was permanently named by IUPAC.[nb 4]
UuuUnununium111Temporary name given to roentgenium until it was permanently named by IUPAC.[nb 4]
UrUranium92Current symbol is U.[nb 1]
ViVirginium87Discredited claim to discovery of francium.[nb 2][7]
VmVirginium87Discredited claim to discovery of francium.[nb 2][7]
VaVanadium23Current symbol is V.[nb 1]
WoTungsten74Current symbol is W.[nb 1]
XXenon54Current symbol is Xe. The symbol is now used for halogens.[nb 1]
YtYttrium39Current symbol is Y.[nb 1][7]

Pictographic symbols

The following is a list of pictographic symbols employed to symbolize elements known since ancient times (for example to the alchemists). Not included in this list are symbolic representations of substances previously called elements (such as certain rare earth mineral blends and the classical elements fire and water of ancient philosophy) which are known today to be multi-atomic. Also not included are symbolic representations currently used for elements in other languages such as the Chinese characters for elements. Modern alphabetic notation was introduced in 1814 by Jöns Jakob Berzelius.

Chemical symbolOriginal nameModern nameAtomic numberOrigin of symbol
HydrogenHydrogen1Daltonian symbol circa 1808.
CarbonCarbon6Daltonian symbol circa 1808.
AzoteNitrogen7Daltonian symbol circa 1808.
OxygenOxygen8Daltonian symbol circa 1808.
SodaSodium11Daltonian symbol circa 1808.
MagnesiumMagnesium12Alchemical symbol.
SulfurSulfur16Alchemical symbol.
PallasSulfur16Alchemical symbol.
🜍SulfurSulfur16Alchemical symbol.
SulfurSulfur16Daltonian symbol circa 1808.
MarsIron26Alchemical symbol.
IronIron26Daltonian symbol circa 1808.
Stellae FixaeCopper29Pre–16th-century alchemical symbol.
VenusCopper29Alchemical symbol.
CopperCopper29Alchemical symbol.
CopperCopper29Daltonian symbol circa 1808.
ZincZinc30Daltonian symbol circa 1808.
ArsenicArsenic33Alchemical symbol.
🜺ArsenicArsenic33Alchemical symbol.
LunaSilver47Alchemical symbol.
🜛SilverSilver47Alchemical symbol.
SilverSilver47Daltonian symbol circa 1808.
IupiterTin50Alchemical symbol.
AntimonyAntimony51Alchemical symbol.
☉☾PlatinumPlatinum78Alchemical symbol.
UranusPlatinum78Alchemical symbol.
SolGold79Alchemical symbol from the 16th century.
SolGold79Alchemical symbol from 1700 through 1783.
🜚GoldGold79Alchemical symbol.
PiscesMercury80Pre–16th-century alchemical symbol.
NeptunusMercury80Alchemical symbol from the 17th century.
MercuriusMercury80Alchemical symbol from 1700 through 1783.
SaturnusLead82Alchemical symbol circa 1783.
LeadLead82Daltonian symbol circa 1808.
TaurusBismuth83Alchemical symbol.

Symbols for named isotopes

The following is a list of isotopes of elements given in the previous tables which have been designated unique symbols. By this it is meant that a comprehensive list of current systematic symbols (in the uAtom form) are not included in the list and can instead be found in the Isotope index chart. The symbols for the named isotopes of hydrogen, deuterium (D) and tritium (T) are still in use today, as is thoron (Tn) for radon-220 (though not actinon; An is usually used instead for a generic actinide). Heavy water and other deuterated solvents 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, d6-benzene and C6D6 can be used instead of [2H6]C6H6.[11]

The symbols for isotopes of elements other than hydrogen and radon are no longer in use within the scientific community. Many of these symbols were designated during the early years of radiochemistry, and several isotopes (namely those in the actinium decay family, the radium decay family, and the thorium decay family) bear placeholder names using the early naming system devised by Ernest Rutherford.[12]

Chemical symbolNameAtomic numberOrigin of symbol
AcActinium89From the Greek aktinos. Name restricted at one time to 227Ac, an isotope of actinium. This named isotope later became the official name for element 89.
AcAActinium A84From actinium and A. Placeholder name given at one time to 215Po, an isotope of polonium identified in the decay chain of actinium.
AcBActinium B82From actinium and B. Placeholder name given at one time to 211Pb, an isotope of lead identified in the decay chain of actinium.
AcCActinium C83From actinium and C. Placeholder name given at one time to 211Bi, an isotope of bismuth identified in the decay chain of actinium.
AcC'Actinium C'84From actinium and C'. Placeholder name given at one time to 211Po, an isotope of polonium identified in the decay chain of actinium.
AcC"Actinium C"81From actinium and C". Placeholder name given at one time to 207Tl, an isotope of thallium identified in the decay chain of actinium.
AcKActinium K87Name given at one time to 223Fr, an isotope of francium identified in the decay chain of actinium.
AcUActino-uranium92Name given at one time to 235U, an isotope of uranium.
AcXActinium X88Name given at one time to 223Ra, an isotope of radium identified in the decay chain of actinium.
AnActinon86From actinium and emanation. Name given at one time to 219Rn, an isotope of radon identified in the decay chain of actinium.
DDeuterium1From the Greek deuteros. Name given to 2H.
IoIonium90Name given to 230Th, an isotope of thorium identified in the decay chain of uranium.
MsTh1Mesothorium 188Name given at one time to 228Ra, an isotope of radium.
MsTh2Mesothorium 289Name given at one time to 228Ac, an isotope of actinium.
PaProtactinium91From the Greek protos and actinium. Name restricted at one time to 231Pa, an isotope of protactinium. This named isotope later became the official name for element 91.
RaRadium88From the Latin radius. Name restricted at one time to 226Ra, an isotope of radium. This named isotope later became the official name for element 88.
RaARadium A84From radium and A. Placeholder name given at one time to 218Po, an isotope of polonium identified in the decay chain of radium.
RaBRadium B82From radium and B. Placeholder name given at one time to 214Pb, an isotope of lead identified in the decay chain of radium.
RaCRadium C83From radium and C. Placeholder name given at one time to 214Bi, an isotope of bismuth identified in the decay chain of radium.
RaC'Radium C'84From radium and C'. Placeholder name given at one time to 214Po, an isotope of polonium identified in the decay chain of radium.
RaC"Radium C"81From radium and C". Placeholder name given at one time to 210Tl, an isotope of thallium identified in the decay chain of radium.
RaDRadium D82From radium and D. Placeholder name given at one time to 210Pb, an isotope of lead identified in the decay chain of radium.
RaERadium E83From radium and E. Placeholder name given at one time to 210Bi, an isotope of bismuth identified in the decay chain of radium.
RaE"Radium E"81From radium and E". Placeholder name given at one time to 206Tl, an isotope of thallium identified in the decay chain of radium.
RaFRadium F84From radium and F. Placeholder name given at one time to 210Po, an isotope of polonium identified in the decay chain of radium.
RdAcRadioactinium90Name given at one time to 227Th, an isotope of thorium.
RdThRadiothorium90Name given at one time to 228Th, an isotope of thorium.
RnRadon86From radium and emanation. Name restricted at one time to 222Rn, an isotope of radon identified in the decay chain of radium. This named isotope later became the official name for element 86 in 1923.
TTritium1From the Greek tritos. Name given to 3H.
ThThorium90After Thor. Name restricted at one time to 232Th, an isotope of thorium. This named isotope later became the official name for element 90.
ThAThorium A84From thorium and A. Placeholder name given at one time to 216Po, an isotope of polonium identified in the decay chain of thorium.
ThBThorium B82From thorium and B. Placeholder name given at one time to 212Pb, an isotope of lead identified in the decay chain of thorium.
ThCThorium C83From thorium and C. Placeholder name given at one time to 212Bi, an isotope of bismuth identified in the decay chain of thorium.
ThC'Thorium C'84From thorium and C'. Placeholder name given at one time to 212Po, an isotope of polonium identified in the decay chain of thorium.
ThC"Thorium C"81From thorium and C". Placeholder name given at one time to 208Tl, an isotope of thallium identified in the decay chain of thorium.
ThXThorium X88Name given at one time to 224Ra, an isotope of radium identified in the decay chain of thorium.
TnThoron86From thorium and emanation. Name given at one time to 220Rn, an isotope of radon identified in the decay chain of thorium.
UIUranium I92Name given at one time to 238U, an isotope of uranium.
UIIUranium II92Name given at one time to 234U, an isotope of uranium.
UX1Uranium X190Name given at one time to 234Th, an isotope of thorium identified in the decay chain of uranium.
UX2Uranium X291Name given at one time to 234mPa, an isotope of protactinium identified in the decay chain of uranium.
UYUranium Y90Name given at one time to 231Th, an isotope of thorium identified in the decay chain of uranium.
UZUranium Z91Name given at one time to 234Pa, an isotope of protactinium identified in the decay chain of uranium.

Other symbols

See also Skeletal formula § Pseudoelement symbols.

General:

From organic chemistry:

Exotic atoms:

See also

Notes

  1. Name changed due to a standardization of, modernization of, or update to older formerly-used symbol.
  2. Name designated by discredited/disputed claimant.
  3. Name proposed prior to discovery/creation of element or prior to official re-naming of a placeholder name.
  4. Temporary placeholder name.

References

  1. "IUPAC Provisional Recommendations: IR-3: Elements and Groups of Elements" (PDF). IUPAC. March 2004. Cite journal requires |journal= (help)
  2. "Periodic Table – Royal Society of Chemistry". www.rsc.org.
  3. "Online Etymology Dictionary". etymonline.com.
  4. Wieser, Michael E.; et al. (2013). "Atomic weights of the elements 2011 (IUPAC Technical Report)". Pure Appl. Chem. 85 (5): 1047–1078. doi:10.1351/PAC-REP-13-03-02. (for standard atomic weights of elements)
  5. Sonzogni, Alejandro. "Interactive Chart of Nuclides". National Nuclear Data Center: Brookhaven National Laboratory. Retrieved 2008-06-06. (for atomic weights of elements with atomic numbers 103–118)
  6. Holden, N. E. (12 March 2004). "History of the Origin of the Chemical Elements and Their Discoverers". National Nuclear Data Center.
  7. Leal, João P. (2013). "The Forgotten Names of Chemical Elements". Foundations of Science. 19 (2): 175–183. doi:10.1007/s10699-013-9326-y.
  8. http://www.encyclopediaofalabama.org/article/h-1672
  9. Fontani, Marco; Costa, Mariagrazia; Orna, Mary Virginia (2014). The Lost Elements: The Periodic Table's Shadow Side. Oxford University Press. ISBN 9780199383344.
  10. Praseodymium. was.chemistryexplained.com.
  11. IUPAC. "Isotopically Modified Compounds". IUPAC. Retrieved 31 March 2015.
  12. Morgan, G. T., ed. (1905). "Annual Reports on the Progress of Chemistry for 1904". Journal of the Chemical Society. Gurney & Jackson. 1: 268. 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.
  13. Jurczyk, M.; Rajewski, W.; Majchrzycki, W.; Wójcik, G. (1999-08-30). "Mechanically alloyed MmNi5-type materials for metal hydride electrodes". Journal of Alloys and Compounds. 290 (1–2): 262–266. doi:10.1016/S0925-8388(99)00202-9.
  • Element name etymologies. Retrieved July 15, 2005.
  • Atomic Weights of the Elements 2001, 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.
  • IUPAC Standard Atomic Weights Revised (2005).
  • WebElements Periodic Table. Retrieved June 30, 2005. Atomic weights of elements with atomic numbers 110–116 taken from this source.
  • Lapp, Ralph E. Matter. Life Science Library. New York: Time, Inc. 1963.
  • 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.
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