Symbol (chemistry)

In relation to the chemical elements, a symbol is a code for a chemical element.[nb 1] Many functional groups have their own chemical symbol, e.g. Ph for the phenyl group, and Me for the methyl group. Chemical symbols for elements normally consist of one or two letters from the Latin alphabet, but can contain three when the element has a systematic temporary name (as of March 2017, no discovered elements have such a name), and are written with the first letter capitalized.

Earlier chemical element symbols 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, "He" is the symbol for helium (New Latin name, not known in ancient Roman times), "Pb" for lead (plumbum in Latin), and "Hg" for mercury (hydrargyrum in Greek). Some symbols come from other sources, like "W" for tungsten (Wolfram in German, not known in Roman times).

Temporary symbols assigned to newly or not-yet synthesized elements use 3-letter symbols based on their atomic numbers. For example, "Uno" was the temporary symbol for hassium (element 108) which had the temporary name of unniloctium.

Chemical symbols may be modified by the use of prepended superscripts or subscripts to specify a particular isotope of an atom. Additionally, appended superscripts may be used to indicate the ionization or oxidation state of an element. They are widely used in chemistry and they have been officially chosen by the International Union of Pure and Applied Chemistry (IUPAC). There are also some historical symbols that are no longer officially used.

Attached subscripts or superscripts specifying a nucleotide 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 then implicit.
  • 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 information values.

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.

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[1][2] Group Period Atomic weight[3][4] (u (±)) Density (g/cm3) Melt (K) [5] Boil (K) C[upper-roman 1] (J/g · K) χ[upper-roman 1] Abundance in Earth's crust[upper-roman 2] (mg/kg)
1HHydrogencomposed of the Greek elements hydro- and -gen meaning 'water-forming'111.008[upper-roman 3][upper-roman 4][upper-roman 5][upper-roman 6]0.0000898814.0120.2814.3042.201400
2HeHeliumthe Greek helios, 'sun'1814.002602(2)[upper-roman 3][upper-roman 5]0.0001785[upper-roman 7]4.225.1930.008
3LiLithiumthe Greek lithos, 'stone'126.94[upper-roman 3][upper-roman 4][upper-roman 5][upper-roman 8][upper-roman 6]0.534453.6915603.5820.9820
4BeBerylliumberyl, a mineral229.0121831(5)1.85156027421.8251.572.8
5BBoronborax, a mineral13210.81[upper-roman 3][upper-roman 4][upper-roman 5][upper-roman 6]2.34234942001.0262.0410
6CCarbonthe Latin carbo, 'coal'14212.011[upper-roman 3][upper-roman 5][upper-roman 6]2.267380043000.7092.55200
7NNitrogenthe Greek nitron and '-gen' meaning 'niter-forming'15214.007[upper-roman 3][upper-roman 5][upper-roman 6]0.001250663.1577.361.043.0419
8OOxygenfrom the Greek oxy-, both 'sharp' and 'acid', and -gen, meaning 'acid-forming'16215.999[upper-roman 3][upper-roman 5][upper-roman 6]0.00142954.3690.200.9183.44461000
9FFluorinethe Latin fluere, 'to flow'17218.998403163(6)0.00169653.5385.030.8243.98585
10NeNeonthe Greek neos, meaning 'new'18220.1797(6)[upper-roman 3][upper-roman 4]0.000899924.5627.071.030.005
11NaSodiumthe English word soda (natrium in Latin)1322.98976928(2)0.971370.8711561.2280.9323600
12MgMagnesiumMagnesia, a district of Eastern Thessaly in Greece2324.305[upper-roman 6]1.73892313631.0231.3123300
13AlAluminiumfrom alumina, a compound (originally alumium)13326.9815385(7)2.698933.4727920.8971.6182300
14SiSiliconfrom the Latin silex, 'flint' (originally silicium)14328.085[upper-roman 5][upper-roman 6]2.3296168735380.7051.9282000
15PPhosphorusthe Greek phoosphoros, 'carrying light'15330.973761998(5)1.82317.305500.7692.191050
16SSulfurthe Latin sulphur, 'fire and brimstone'16332.06[upper-roman 3][upper-roman 5][upper-roman 6]2.067388.36717.870.712.58350
17ClChlorinethe Greek chloros, 'greenish yellow'17335.45[upper-roman 3][upper-roman 4][upper-roman 5][upper-roman 6]0.003214171.6239.110.4793.16145
18ArArgonthe Greek argos, 'idle'18339.948(1)[upper-roman 3][upper-roman 5]0.001783783.8087.300.523.5
19KPotassiumNew Latin potassa, 'potash' (kalium in Latin)1439.0983(1)0.862336.5310320.7570.8220900
20CaCalciumthe Latin calx, 'lime'2440.078(4)[upper-roman 3]1.54111517570.647141500
21ScScandiumScandia, the Latin name for Scandinavia3444.955908(5)2.989181431090.5681.3622
22TiTitaniumTitans, the sons of the Earth goddess of Greek mythology4447.867(1)4.54194135600.5231.545650
23VVanadiumVanadis, an Old Norse name for the Scandinavian goddess Freyja5450.9415(1)6.11218336800.4891.63120
24CrChromiumthe Greek chroma, 'colour'6451.9961(6)7.15218029440.4491.66102
25MnManganesecorrupted from magnesia negra, see Magnesium7454.938044(3)7.44151923340.4791.55950
26FeIronEnglish word (ferrum in Latin)8455.845(2)7.874181131340.4491.8356300
27CoCobaltthe German word Kobold, 'goblin'9458.933194(4)8.86176832000.4211.8825
28NiNickelfrom a mischievous sprite of German miner mythology, Nickel10458.6934(4)8.912172831860.4441.9184
29CuCopperEnglish word (Latin cuprum)11463.546(3)[upper-roman 5]8.961357.7728350.3851.960
30ZnZincGerman word Zinke (prong, tooth)12465.38(2)7.134692.8811800.3881.6570
31GaGalliumGallia, the Latin name for France13469.723(1)5.907302.914626730.3711.8119
32GeGermaniumGermania, the Latin name for Germany14472.630(8)5.3231211.4031060.322.011.5
33AsArsenicEnglish word (Latin arsenicum)15474.921595(6)5.7761090 [upper-roman 9]8870.3292.181.8
34SeSeleniumthe Greek selene, 'moon'16478.971(8)[upper-roman 5]4.8094539580.3212.550.05
35BrBrominethe Greek bromos, 'stench'17479.904[upper-roman 6]3.122265.8332.00.4742.962.4
36KrKryptonthe Greek kryptos, 'hidden'18483.798(2)[upper-roman 3][upper-roman 4]0.003733115.79119.930.24831×10−4
37RbRubidiumthe Latin rubidus, 'deep red'1585.4678(3)[upper-roman 3]1.532312.469610.3630.8290
38SrStrontiumStrontian, a small town in Scotland2587.62(1)[upper-roman 3][upper-roman 5]2.64105016550.3010.95370
39YYttriumYtterby, Sweden3588.90584(2)4.469179936090.2981.2233
40ZrZirconiumPersian Zargun, 'gold-colored'; German Zirkoon, 'jargoon'4591.224(2)[upper-roman 3]6.506212846820.2781.33165
41NbNiobiumNiobe, daughter of king Tantalus from Greek mythology5592.90637(2)8.57275050170.2651.620
42MoMolybdenumthe Greek molybdos meaning 'lead'6595.95(1)[upper-roman 3]10.22289649120.2512.161.2
43TcTechnetiumthe Greek tekhnètos meaning 'artificial'75[98][upper-roman 10]11.5243045381.9~ 3×10−9[upper-roman 11]
44RuRutheniumRuthenia, the New Latin name for Russia85101.07(2)[upper-roman 3]12.37260744230.2382.20.001
45RhRhodiumthe Greek rhodos, meaning 'rose coloured'95102.90550(2)12.41223739680.2432.280.001
46PdPalladiumthe then recently discovered asteroid Pallas, considered a planet at the time105106.42(1)[upper-roman 3]12.021828.0532360.2442.20.015
47AgSilverEnglish word (argentum in Latin)115107.8682(2)[upper-roman 3]10.5011234.9324350.2351.930.075
48CdCadmiumthe New Latin cadmia, from King Kadmos125112.414(4)[upper-roman 3]8.69594.2210400.2321.690.159
49InIndiumindigo135114.818(1)7.31429.7523450.2331.780.25
50SnTinEnglish word (stannum in Latin)145118.710(7)[upper-roman 3]7.287505.0828750.2281.962.3
51SbAntimonyuncertain: perhaps from the Greek anti, 'against', and monos, 'alone', or the Old French antimoine, 'Monk's bane' (stibium in Latin)155121.760(1)[upper-roman 3]6.685903.7818600.2072.050.2
52TeTelluriumLatin tellus, 'earth'165127.60(3)[upper-roman 3]6.232722.6612610.2022.10.001
53IIodineFrench iode (after the Greek ioeides, 'violet')175126.90447(3)4.93386.85457.40.2142.660.45
54XeXenonthe Greek xenos, 'strange'185131.293(6)[upper-roman 3][upper-roman 4]0.005887161.4165.030.1582.63×10−5
55CsCaesiumthe Latin caesius, 'sky blue'16132.90545196(6)1.873301.599440.2420.793
56BaBariumthe Greek barys, 'heavy'26137.327(7)3.594100021700.2040.89425
57LaLanthanumthe Greek lanthanein, 'to lie hidden'36138.90547(7)[upper-roman 3]6.145119337370.1951.139
58CeCeriumthe then recently discovered asteroid Ceres, considered a planet at the time6140.116(1)[upper-roman 3]6.77106837160.1921.1266.5
59PrPraseodymiumthe Greek praseios didymos meaning 'green twin'6140.90766(2)6.773120837930.1931.139.2
60NdNeodymiumthe Greek neos didymos meaning 'new twin'6144.242(3)[upper-roman 3]7.007129733470.191.1441.5
61PmPromethiumPrometheus of Greek mythology who stole fire from the Gods and gave it to humans6[145][upper-roman 10]7.26131532731.132×10−19[upper-roman 11]
62SmSamariumSamarskite, the name of the mineral from which it was first isolated6150.36(2)[upper-roman 3]7.52134520670.1971.177.05
63EuEuropiumEurope6151.964(1)[upper-roman 3]5.243109918020.1821.22
64GdGadoliniumJohan Gadolin, chemist, physicist and mineralogist6157.25(3)[upper-roman 3]7.895158535460.2361.26.2
65TbTerbiumYtterby, Sweden6158.92535(2)8.229162935030.1821.21.2
66DyDysprosiumthe Greek dysprositos, 'hard to get'6162.500(1)[upper-roman 3]8.55168028400.171.225.2
67HoHolmiumHolmia, the New Latin name for Stockholm6164.93033(2)8.795173429930.1651.231.3
68ErErbiumYtterby, Sweden6167.259(3)[upper-roman 3]9.066180231410.1681.243.5
69TmThuliumThule, the ancient name for Scandinavia6168.93422(2)9.321181822230.161.250.52
70YbYtterbiumYtterby, Sweden6173.045(10)[upper-roman 3]6.965109714690.1551.13.2
71LuLutetiumLutetia, the Latin name for Paris6174.9668(1)[upper-roman 3]9.84192536750.1541.270.8
72HfHafniumHafnia, the New Latin name for Copenhagen46178.49(2)13.31250648760.1441.33
73TaTantalumKing Tantalus, father of Niobe from Greek mythology56180.94788(2)16.654329057310.141.52
74WTungstenthe Swedish tung sten, 'heavy stone' (W is wolfram, the old name of the tungsten mineral wolframite)66183.84(1)19.25369558280.1322.361.3
75ReRheniumRhenus, the Latin name for the river Rhine76186.207(1)21.02345958690.1371.97×10−4
76OsOsmiumthe Greek osmè, meaning 'smell'86190.23(3)[upper-roman 3]22.61330652850.132.20.002
77IrIridiumIris, the Greek goddess of the rainbow96192.217(3)22.56271947010.1312.20.001
78PtPlatinumthe Spanish platina, meaning 'little silver'106195.084(9)21.462041.440980.1332.280.005
79AuGoldEnglish word (aurum in Latin)116196.966569(5)19.2821337.3331290.1292.540.004
80HgMercurythe New Latin name mercurius, named after the Roman god (Hg from former name hydrargyrum, from Greek hydr-, 'water', and argyros, 'silver')126200.592(3)13.5336234.43629.880.1420.085
81TlThalliumthe Greek thallos, 'green twig'136204.38[upper-roman 6]11.8557717460.1291.620.85
82PbLeadEnglish word (plumbum in Latin)146207.2(1)[upper-roman 3][upper-roman 5]11.342600.6120220.1291.8714
83BiBismuthUncertain, possibly Arabic or German156208.98040(1)[upper-roman 10]9.807544.718370.1222.020.009
84PoPoloniumNamed after the home country of Marie Curie (Polonia, Latin for Poland), who is also the discoverer of Radium166[209][upper-roman 10]9.3252712352.02×10−10[upper-roman 11]
85AtAstatinethe Greek astatos, 'unstable'176[210][upper-roman 10]75756102.23×10−20[upper-roman 11]
86RnRadonFrom radium, as it was first detected as an emission from radium during radioactive decay186[222][upper-roman 10]0.00973202211.30.0942.24×10−13[upper-roman 11]
87FrFranciumFrancia, the New Latin name for France17[223][upper-roman 10]1.873009500.7~ 1×10−18[upper-roman 11]
88RaRadiumthe Latin radius, 'ray'27[226][upper-roman 10]5.597320100.0940.99×10−7[upper-roman 11]
89AcActiniumthe Greek aktis, 'ray'37[227][upper-roman 10]10.07132334710.121.15.5×10−10[upper-roman 11]
90ThThoriumThor, the Scandinavian god of thunder7232.0377(4)[upper-roman 10][upper-roman 3]11.72211550610.1131.39.6
91PaProtactiniumthe Greek protos, 'first', and actinium, which is produced through the radioactive decay of protactinium7231.03588(2)[upper-roman 10]15.37184143001.51.4×10−6[upper-roman 11]
92UUraniumUranus, the seventh planet in the Solar System7238.02891(3)[upper-roman 10]18.951405.344040.1161.382.7
93NpNeptuniumNeptune, the eighth planet in the Solar System7[237][upper-roman 10]20.4591742731.36 3×10−12[upper-roman 11]
94PuPlutoniumPluto, a dwarf planet in the Solar System (then considered the ninth planet)7[244][upper-roman 10]19.84912.535011.28 3×10−11[upper-roman 11]
95AmAmericiumThe Americas, as the element was first synthesised on the continent, by analogy with europium7[243][upper-roman 10]13.69144928801.130[upper-roman 12]
96CmCuriumPierre Curie, a physicist, and Marie Curie, a physicist and chemist, named after great scientists by analogy with gadolinium7[247][upper-roman 10]13.51161333831.280[upper-roman 12]
97BkBerkeliumBerkeley, California, where the element was first synthesised, by analogy with terbium7[247][upper-roman 10]14.79125929001.30[upper-roman 12]
98CfCaliforniumCalifornia, where the element was first synthesised7[251][upper-roman 10]15.11173(1743)[upper-roman 13]1.30[upper-roman 12]
99EsEinsteiniumAlbert Einstein, physicist7[252][upper-roman 10]8.841133(1269)[upper-roman 13]1.30[upper-roman 12]
100FmFermiumEnrico Fermi, physicist7[257][upper-roman 10](9.7)[upper-roman 13](1125)[upper-roman 13]1.30[upper-roman 12]
101MdMendeleviumDmitri Mendeleev, chemist and inventor7[258][upper-roman 10](10.3)[upper-roman 13](1100)[upper-roman 13]1.30[upper-roman 12]
102NoNobeliumAlfred Nobel, chemist, engineer, inventor of dynamite7[259][upper-roman 10](9.9)[upper-roman 13](1100)[upper-roman 13]1.30[upper-roman 12]
103LrLawrenciumErnest O. Lawrence, physicist7[266][upper-roman 10](15.6)[upper-roman 13](1900)[upper-roman 13]1.30[upper-roman 12]
104RfRutherfordiumErnest Rutherford, chemist and physicist47[267][upper-roman 10](23.2)[upper-roman 13](2400)[upper-roman 13](5800)[upper-roman 13]0[upper-roman 12]
105DbDubniumDubna, Russia57[268][upper-roman 10](29.3)[upper-roman 13]0[upper-roman 12]
106SgSeaborgiumGlenn T. Seaborg, scientist67[269][upper-roman 10](35.0)[upper-roman 13]0[upper-roman 12]
107BhBohriumNiels Bohr, physicist77[270][upper-roman 10](37.1)[upper-roman 13]0[upper-roman 12]
108HsHassiumHesse, Germany, where the element was first synthesised87[277][upper-roman 10](40.7)[upper-roman 13]0[upper-roman 12]
109MtMeitneriumLise Meitner, physicist97[278][upper-roman 10](37.4)[upper-roman 13]0[upper-roman 12]
110DsDarmstadtiumDarmstadt, Germany, where the element was first synthesised107[281][upper-roman 10](34.8)[upper-roman 13]0[upper-roman 12]
111RgRoentgeniumWilhelm Conrad Röntgen, physicist117[282][upper-roman 10](28.7)[upper-roman 13]0[upper-roman 12]
112CnCoperniciumNicolaus Copernicus, astronomer127[285][upper-roman 10](23.7)[upper-roman 13]~357[upper-roman 14]0[upper-roman 12]
113NhNihoniumthe Japanese name for Japan, Nihon, where the element was first synthesised137[286][upper-roman 10](16)[upper-roman 13](700)[upper-roman 13](1400)[upper-roman 13]0[upper-roman 12]
114FlFleroviumFlerov Laboratory of Nuclear Reactions, part of JINR where the element was synthesised; itself named for Georgy Flyorov, physicist147[289][upper-roman 10](14)[upper-roman 13]~2100[upper-roman 12]
115McMoscoviumMoscow Oblast, Russia, where the element was first synthesised157[290][upper-roman 10](13.5)[upper-roman 13](700)[upper-roman 13](1400)[upper-roman 13]0[upper-roman 12]
116LvLivermoriumLawrence Livermore National Laboratory (in Livermore, California) which collaborated with JINR on its synthesis167[293][upper-roman 10](12.9)[upper-roman 13](709)[upper-roman 13](1085)[upper-roman 13]0[upper-roman 12]
117TsTennessineTennessee, United States177[294][upper-roman 10](7.2)[upper-roman 13](723)[upper-roman 13](883)[upper-roman 13]0[upper-roman 12]
118OgOganessonYuri Oganessian, physicist187[294][upper-roman 10](5.0)[upper-roman 13][upper-roman 15](350)[upper-roman 13]0[upper-roman 12]

Notes

  1. Z is the standard symbol for atomic number; C is the standard symbol for heat capacity; and χ is the standard symbol for electronegativity on the Pauling scale.
  2. Unless otherwise indicated, elements are primordial – they occur naturally, and not through decay.
  3. The isotopic composition of this element varies in some geological specimens, and the variation may exceed the uncertainty stated in the table.
  4. The isotopic composition of the element can vary in commercial materials, which can cause the atomic weight to deviate significantly from the given value.
  5. The isotopic composition varies in terrestrial material such that a more precise atomic weight can not be given.
  6. 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]
    • Bromine: [79.901, 79.907]
    • Thallium: [204.382, 204.385]
  7. Helium does not solidify at a pressure of one atmosphere. Helium can only solidify at pressures above 25 atmospheres, which corresponds to a melting point of absolute zero.
  8. 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.
  9. This element sublimes at one atmosphere of pressure.
  10. 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.
  11. This element is transient – it occurs only through decay.
  12. This element is synthetic – the transuranic elements 95 and above do not occur naturally, but they can all be produced artificially.
  13. The value has not been precisely measured, usually because of the element's short half-life; the value given in parentheses is a prediction.
  14. With error bars: 357+112
    −108
     K.
  15. This predicted value is for liquid oganesson, not gaseous oganesson.

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 2][6]
AbAlabamine85Discredited claim to discovery of astatine.[nb 3][7]
AdAldebaranium70Former name for ytterbium.[nb 3]
AmAlabamium85Discredited claim to discovery of astatine. The symbol is now used for americium.[nb 3][7]
AnAthenium99Proposed name for einsteinium.[nb 4]
AoAusonium93Discredited claim to discovery of neptunium.[nb 3][7]
AzAzote7Former name for nitrogen.[nb 2]
BoBoron5Current symbol is B.[nb 2]
BvBrevium91Former name for protactinium.[nb 2]
BzBerzelium90Baskerville wrongly believed berzelium to be a new element. Was actually thorium.[nb 4][8]
CbColumbium41Former name for niobium.[nb 2][7][8]
ChChromium24Current symbol is Cr.[nb 2]
ClColumbium41Former name for niobium. The symbol is now used for chlorine.[nb 2]
CnCarolinium90Baskerville wrongly believed carolinium to be a new element. Was actually thorium. The symbol is now used for copernicium.[8]
CpCassiopeium71Former name for lutetium.[nb 2]
CpCopernicium112Current symbol is Cn.[nb 2]
CtCeltium72Discredited claim to discovery of hafnium.[nb 3]
CtCenturium100Proposed name for fermium.[nb 4]
DDidymium59/60Mixture of the elements praseodymium and neodymium. Mosander wrongly believed didymium to be an element.[9]
DaDavyum43Discredited claim to discovery of technetium.[nb 3][7]
DbDubnium104Proposed name for rutherfordium. The symbol and name were instead used for element 105.[nb 2][nb 4][7]
DiDidymium59/60Mixture of the elements praseodymium and neodymium. Mosander wrongly believed didymium to be an element.[9]
DsDysprosium66Current symbol is Dy. The symbol is now used for darmstadtium.[nb 2]
EEinsteinium99Current symbol is Es.[nb 2]
EErbium68Current symbol is Er.[nb 2]
EaEkaaluminium31Name given by Mendeleev to an as of then undiscovered element. When discovered, gallium closely matched the prediction.[nb 4][nb 5]
EbEkaboron21Name given by Mendeleev to an as of then undiscovered element. When discovered, scandium closely matched the prediction.[nb 4][nb 5][7]
ElEkaaluminium31Name given by Mendeleev to an as of then undiscovered element. When discovered, gallium closely matched the prediction.[nb 4][nb 5][7]
EmEkamanganese43Name given by Mendeleev to an as of then undiscovered element. When discovered, technetium closely matched the prediction.[nb 4][nb 5][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 2][7]
EmEmanium89Alternate name formerly proposed for actinium.[nb 4]
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 4][nb 5][7]
EsEsperium94Discredited claim to discovery of plutonium. The symbol is now used for einsteinium.[nb 3][7]
FaFrancium87Current symbol is Fr.[nb 2]
FlFlorentium61Discredited claim to discovery of promethium. The symbol is now used for flerovium.[nb 3]
FlFluorine9Current symbol is F. The symbol is now used for flerovium.[nb 2]
FrFlorentium61Discredited claim to discovery of promethium. The symbol is now used for francium.[nb 3][7]
GGlucinium4Former name for beryllium.[nb 2]
GlGlucinium4Former name for beryllium.[nb 2][7]
HaHahnium105Proposed name for dubnium.[nb 4]
HnHahnium108Proposed name for hassium.[nb 4][7]
HvHelvetium85Discredited claim to discovery of astatine.[nb 3][8]
HyMercury80Hy from the Greek hydrargyrum for "liquid silver". Current symbol is Hg.[nb 2][6]
IIridium77Current symbol is Ir. The symbol is now used for iodine.[nb 2]
IlIllinium61Discredited claim to discovery of promethium.[nb 3][7]
JJodium53Former name for iodine.[nb 2]
JgJargonium72Discredited claim to discovery of hafnium.[nb 3][7]
JlJoliotium105Proposed name for dubnium.[nb 4][7]
KaPotassium19Current symbol is K.[nb 2]
KuKurchatovium104Proposed name for rutherfordium.[nb 4][7]
LLithium3Current symbol is Li.[nb 2]
LwLawrencium103Current symbol is Lr.[nb 2]
MMuriaticum17Former name for chlorine.[nb 2]
MaManganese25Current symbol is Mn.[nb 2]
MaMasurium43Disputed claim to discovery of technetium.[nb 3][7]
MdMendelevium97Proposed name for berkelium. The symbol and name were later used for element 101.[nb 2][nb 4]
MlMoldavium87Discredited claim to discovery of francium.[nb 3][8]
MsMagnesium12Current symbol is Mg.[nb 2]
MsMasurium43Disputed claim to discovery of technetium.[nb 3]
MvMendelevium101Current symbol is Md.[nb 2]
NgNorwegium72Discredited claim to discovery of hafnium.[nb 3]
NoNorium72Discredited claim to discovery of hafnium. The symbol is now used for nobelium.[nb 3]
NpNipponium43Discredited claim to discovery of technetium. The symbol is now used for neptunium.[nb 3][7]
NsNielsbohrium105Proposed name for dubnium.[nb 4][7]
NsNielsbohrium107Proposed name for bohrium.[nb 4][7]
NtNiton86Former name for radon.[nb 2][7]
NyNeoytterbium70Former name for ytterbium.[nb 2]
PLead82Current symbol is Pb. The symbol is now used for phosphorus.[nb 2]
PaPalladium46Current symbol is Pd. The symbol is now used for protactinium.[nb 2]
PePelopium41Former name for niobium.[nb 2]
PlPalladium46Current symbol is Pd.[nb 2]
PoPotassium19Current symbol is K. The symbol is now used for polonium.[nb 2]
RRhodium45Current symbol is Rh.[nb 2]
RdRadium88Current symbol is Ra.[nb 2]
RfRutherfordium106Proposed name for seaborgium. The symbol and name were instead used for element 104.[nb 2][nb 4][7]
RoRhodium45Current symbol is Rh.[nb 2]
SaSamarium62Current symbol is Sm.[nb 2][7]
SoSodium11Current symbol is Na.[nb 2]
StAntimony51Current symbol is Sb.[nb 2]
StTin50Current symbol is Sn.[nb 2]
TnTungsten74Current symbol is W.[nb 2]
TrTerbium65Current symbol is Tb.[nb 2]
TuThulium69Current symbol is Tm.[nb 2]
TuTungsten74Current symbol is W.[nb 2]
UnbUnnilbium102Temporary name given to nobelium until it was permanently named by IUPAC.[nb 5]
UneUnnilennium109Temporary name given to meitnerium until it was permanently named by IUPAC.[nb 5]
UnhUnnilhexium106Temporary name given to seaborgium until it was permanently named by IUPAC.[nb 5]
UnoUnniloctium108Temporary name given to hassium until it was permanently named by IUPAC.[nb 5]
UnpUnnilpentium105Temporary name given to dubnium until it was permanently named by IUPAC.[nb 5]
UnqUnnilquadium104Temporary name given to rutherfordium until it was permanently named by IUPAC.[nb 5]
UnsUnnilseptium107Temporary name given to bohrium until it was permanently named by IUPAC.[nb 5]
UntUnniltrium103Temporary name given to lawrencium until it was permanently named by IUPAC.[nb 5]
UnuUnnilunium101Temporary name given to mendelevium until it was permanently named by IUPAC.[nb 5]
UubUnunbium112Temporary name given to copernicium until it was permanently named by IUPAC.[nb 5]
UuhUnunhexium116Temporary name given to livermorium until it was permanently named by IUPAC.[nb 5]
UunUnunnilium110Temporary name given to darmstadtium until it was permanently named by IUPAC.[nb 5]
UuoUnunoctium118Temporary name given to oganesson until it was permanently named by IUPAC.[nb 5]
UupUnunpentium115Temporary name given to moscovium until it was permanently named by IUPAC.[nb 5]
UuqUnunquadium114Temporary name given to flerovium until it was permanently named by IUPAC.[nb 5]
UusUnunseptium117Temporary name given to tennessine until it was permanently named by IUPAC.[nb 5]
UutUnuntrium113Temporary name given to nihonium until it was permanently named by IUPAC.[nb 5]
UuuUnununium111Temporary name given to roentgenium until it was permanently named by IUPAC.[nb 5]
UrUranium92Current symbol is U.[nb 2]
ViVirginium87Discredited claim to discovery of francium.[nb 3][7]
VmVirginium87Discredited claim to discovery of francium.[nb 3][7]
VaVanadium23Current symbol is V.[nb 2]
WoTungsten74Current symbol is W.[nb 2]
XXenon54Current symbol is Xe. The symbol is now used for halogens.[nb 2]
YtYttrium39Current symbol is Y.[nb 2][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.[10]

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.[11]

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. This should not be confused with formula. When a number is present at the bottom right corner of the symbol of the element, only then is it said to be a formula, but if the number is not present, it is a symbol.
  2. Name changed due to a standardization of, modernization of, or update to older formerly-used symbol.
  3. Name designated by discredited/disputed claimant.
  4. Name proposed prior to discovery/creation of element or prior to official re-naming of a placeholder name.
  5. Temporary placeholder name.

References

  1. "Periodic Table – Royal Society of Chemistry". www.rsc.org.
  2. "Online Etymology Dictionary". etymonline.com.
  3. Wieser, Michael E.; et al. (2013). "Atomic weights of the elements 2011 (IUPAC Technical Report)". Pure Appl. Chem. IUPAC. 85 (5): 1047–1078. doi:10.1351/PAC-REP-13-03-02. (for standard atomic weights of elements)
  4. 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)
  5. Holman, S. W.; Lawrence, R. R.; Barr, L. (1 January 1895). "Melting Points of Aluminum, Silver, Gold, Copper, and Platinum". Proceedings of the American Academy of Arts and Sciences. 31: 218–233. doi:10.2307/20020628. JSTOR 20020628.
  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: 175–183. doi:10.1007/s10699-013-9326-y.
  8. Fontani, Marco; Costa, Mariagrazia; Orna, Mary Virginia (2014). The Lost Elements: The Periodic Table's Shadow Side. Oxford University Press. ISBN 9780199383344.
  9. Praseodymium. was.chemistryexplained.com.
  10. IUPAC. "Isotopically Modified Compounds". IUPAC. Retrieved 31 March 2015.
  11. 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.
  12. 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.

External links

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