Symbol (chemistry)

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In relation to the chemical elements, a symbol is a code for a chemical element.[nb 1] Symbols for chemical elements normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised. (Many functional groups have their own chemical symbol, e.g. Ph for the phenyl group, and Me for the methyl group.)

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 letter(s) 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.

Annotated example of an atomic 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.

The periodic table, elements being denoted by their symbols

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[edit]

List of chemical elements
Z[I] Symbol Element Origin of name[2][3] Group Period Atomic weight[4][5] (u (±))
 
1 H Hydrogen Greek elements hydro- and -gen, meaning 'water-forming' 1 1 1.008[II][III][IV][V]
2 He Helium Greek hḗlios, 'sun' 18 1 4.002602(2)[II][IV]
3 Li Lithium Greek líthos, 'stone' 1 2 6.94[II][III][IV][VI][V]
4 Be Beryllium beryl, a mineral (ultimately from the name of Belur in southern India) 2 2 9.0121831(5)
5 B Boron borax, a mineral (from Arabic bawraq) 13 2 10.81[II][III][IV][V]
6 C Carbon Latin carbo, 'coal' 14 2 12.011[II][IV][V]
7 N Nitrogen Greek nítron and -gen, meaning 'niter-forming' 15 2 14.007[II][IV][V]
8 O Oxygen Greek oxy- and -gen, meaning 'acid-forming' 16 2 15.999[II][IV][V]
9 F Fluorine Latin fluere, 'to flow' 17 2 18.998403163(6)
10 Ne Neon Greek néon, 'new' 18 2 20.1797(6)[II][III]
11 Na Sodium English soda (the symbol Na is derived from New Latin natrium, coined from German Natron, 'natron') 1 3 22.98976928(2)
12 Mg Magnesium Magnesia, a district of Eastern Thessaly in Greece 2 3 24.305[V]
13 Al Aluminium alumina, from Latin alumen (gen. aluminis), 'bitter salt, alum' 13 3 26.9815384(3)
14 Si Silicon Latin silex, 'flint' (originally silicium) 14 3 28.085[IV][V]
15 P Phosphorus Greek phōsphóros, 'light-bearing' 15 3 30.973761998(5)
16 S Sulfur Latin sulphur, 'brimstone' 16 3 32.06[II][IV][V]
17 Cl Chlorine Greek chlōrós, 'greenish yellow' 17 3 35.45[II][III][IV][V]
18 Ar Argon Greek argós, 'idle' (because of its inertness) 18 3 39.948[II][IV][V]
19 K Potassium New Latin potassa, 'potash' (the symbol K is derived from Latin kalium) 1 4 39.0983(1)
20 Ca Calcium Latin calx, 'lime' 2 4 40.078(4)[II]
21 Sc Scandium Latin Scandia, 'Scandinavia' 3 4 44.955908(5)
22 Ti Titanium Titans, the sons of the Earth goddess of Greek mythology 4 4 47.867(1)
23 V Vanadium Vanadis, an Old Norse name for the Scandinavian goddess Freyja 5 4 50.9415(1)
24 Cr Chromium Greek chróma, 'colour' 6 4 51.9961(6)
25 Mn Manganese corrupted from magnesia negra; see Magnesium 7 4 54.938043(2)
26 Fe Iron English word (the symbol Fe is derived from Latin ferrum) 8 4 55.845(2)
27 Co Cobalt German Kobold, 'goblin' 9 4 58.933194(3)
28 Ni Nickel Nickel, a mischievous sprite of German miner mythology 10 4 58.6934(4)
29 Cu Copper English word, from Latin cuprum, from Ancient Greek Kýpros 'Cyprus' 11 4 63.546(3)[IV]
30 Zn Zinc Most likely from German Zinke, 'prong' or 'tooth', though some suggest Persian sang, 'stone' 12 4 65.38(2)
31 Ga Gallium Latin Gallia, 'France' 13 4 69.723(1)
32 Ge Germanium Latin Germania, 'Germany' 14 4 72.630(8)
33 As Arsenic French arsenic, from Greek arsenikón 'yellow arsenic' (influenced by arsenikós, 'masculine' or 'virile'), from a West Asian wanderword ultimately from Old Iranian *zarniya-ka, 'golden' 15 4 74.921595(6)
34 Se Selenium Greek selḗnē, 'moon' 16 4 78.971(8)[IV]
35 Br Bromine Greek brômos, 'stench' 17 4 79.904[V]
36 Kr Krypton Greek kryptós, 'hidden' 18 4 83.798(2)[II][III]
37 Rb Rubidium Latin rubidus, 'deep red' 1 5 85.4678(3)[II]
38 Sr Strontium Strontian, a village in Scotland 2 5 87.62(1)[II][IV]
39 Y Yttrium Ytterby, a village in Sweden 3 5 88.90584(1)
40 Zr Zirconium zircon, a mineral 4 5 91.224(2)[II]
41 Nb Niobium Niobe, daughter of king Tantalus from Greek mythology 5 5 92.90637(1)
42 Mo Molybdenum Greek molýbdaina, 'piece of lead', from mólybdos, 'lead' 6 5 95.95(1)[II]
43 Tc Technetium Greek tekhnētós, 'artificial' 7 5 [98][VII]
44 Ru Ruthenium New Latin Ruthenia, 'Russia' 8 5 101.07(2)[II]
45 Rh Rhodium Greek rhodóeis, 'rose-coloured', from rhódon, 'rose' 9 5 102.90549(2)
46 Pd Palladium the asteroid Pallas, considered a planet at the time 10 5 106.42(1)[II]
47 Ag Silver English word (The symbol derives from Latin argentum) 11 5 107.8682(2)[II]
48 Cd Cadmium New Latin cadmia, from King Kadmos 12 5 112.414(4)[II]
49 In Indium Latin indicum, 'indigo' (colour found in its spectrum) 13 5 114.818(1)
50 Sn Tin English word (The symbol derives from Latin stannum) 14 5 118.710(7)[II]
51 Sb Antimony Latin 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'.) 15 5 121.760(1)[II]
52 Te Tellurium Latin tellus, 'the ground, earth' 16 5 127.60(3)[II]
53 I Iodine French iode, from Greek ioeidḗs, 'violet') 17 5 126.90447(3)
54 Xe Xenon Greek xénon, neuter form of xénos 'strange' 18 5 131.293(6)[II][III]
55 Cs Caesium Latin caesius, 'sky-blue' 1 6 132.90545196(6)
56 Ba Barium Greek barýs, 'heavy' 2 6 137.327(7)
57 La Lanthanum Greek lanthánein, 'to lie hidden' 3 6 138.90547(7)[II]
58 Ce Cerium the dwarf planet Ceres, considered a planet at the time 6 140.116(1)[II]
59 Pr Praseodymium Greek prásios dídymos, 'green twin' 6 140.90766(1)
60 Nd Neodymium Greek néos dídymos, 'new twin' 6 144.242(3)[II]
61 Pm Promethium Prometheus of Greek mythology 6 [145][VII]
62 Sm Samarium samarskite, a mineral named after Colonel Vasili Samarsky-Bykhovets, Russian mine official 6 150.36(2)[II]
63 Eu Europium Europe 6 151.964(1)[II]
64 Gd Gadolinium gadolinite, a mineral named after Johan Gadolin, Finnish chemist, physicist and mineralogist 6 157.25(3)[II]
65 Tb Terbium Ytterby, a village in Sweden 6 158.925354(8)
66 Dy Dysprosium Greek dysprósitos, 'hard to get' 6 162.500(1)[II]
67 Ho Holmium New Latin Holmia, 'Stockholm' 6 164.930328(7)
68 Er Erbium Ytterby, a village in Sweden 6 167.259(3)[II]
69 Tm Thulium Thule, the ancient name for an unclear northern location 6 168.934218(6)
70 Yb Ytterbium Ytterby, a village in Sweden 6 173.045(10)[II]
71 Lu Lutetium Latin Lutetia, 'Paris' 6 174.9668(1)[II]
72 Hf Hafnium New Latin Hafnia, 'Copenhagen' (from Danish havn) 4 6 178.49(2)
73 Ta Tantalum King Tantalus, father of Niobe from Greek mythology 5 6 180.94788(2)
74 W Tungsten Swedish tung sten, 'heavy stone' (The symbol is from wolfram, the old name of the tungsten mineral wolframite) 6 6 183.84(1)
75 Re Rhenium Latin Rhenus, 'the Rhine' 7 6 186.207(1)
76 Os Osmium Greek osmḗ, 'smell' 8 6 190.23(3)[II]
77 Ir Iridium Iris, the Greek goddess of the rainbow 9 6 192.217(2)
78 Pt Platinum Spanish platina, 'little silver', from plata 'silver' 10 6 195.084(9)
79 Au Gold English word (The symbol derives from Latin aurum) 11 6 196.966570(4)
80 Hg Mercury Mercury, 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') 12 6 200.592(3)
81 Tl Thallium Greek thallós, 'green shoot or twig' 13 6 204.38[V]
82 Pb Lead English word (The symbol derives from Latin plumbum) 14 6 207.2(1)[II][IV]
83 Bi Bismuth German Wismut, from weiß Masse 'white mass', unless from Arabic 15 6 208.98040(1)[VII]
84 Po Polonium Latin Polonia, 'Poland' (the home country of Marie Curie) 16 6 [209][VII]
85 At Astatine Greek ástatos, 'unstable' 17 6 [210][VII]
86 Rn Radon radium 18 6 [222][VII]
87 Fr Francium France 1 7 [223][VII]
88 Ra Radium French radium, from Latin radius, 'ray' 2 7 [226][VII]
89 Ac Actinium Greek aktís, 'ray' 3 7 [227][VII]
90 Th Thorium Thor, the Scandinavian god of thunder 7 232.0377(4)[VII][II]
91 Pa Protactinium proto- (from Greek prôtos, 'first, before') + actinium, which is produced through the radioactive decay of protactinium 7 231.03588(1)[VII]
92 U Uranium Uranus, the seventh planet in the Solar System 7 238.02891(3)[VII]
93 Np Neptunium Neptune, the eighth planet in the Solar System 7 [237][VII]
94 Pu Plutonium the dwarf planet Pluto, considered the ninth planet in the Solar System at the time 7 [244][VII]
95 Am Americium The Americas, as the element was first synthesised on the continent, by analogy with europium 7 [243][VII]
96 Cm Curium Pierre Curie and Marie Curie, French physicists and chemists 7 [247][VII]
97 Bk Berkelium Berkeley, California, where the element was first synthesised, by analogy with terbium 7 [247][VII]
98 Cf Californium California, where the element was first synthesised 7 [251][VII]
99 Es Einsteinium Albert Einstein, German physicist 7 [252][VII]
100 Fm Fermium Enrico Fermi, Italian physicist 7 [257][VII]
101 Md Mendelevium Dmitri Mendeleev, Russian chemist and inventor who proposed the periodic table 7 [258][VII]
102 No Nobelium Alfred Nobel, Swedish chemist and engineer 7 [259][VII]
103 Lr Lawrencium Ernest O. Lawrence, American physicist 7 [266][VII]
104 Rf Rutherfordium Ernest Rutherford, British chemist and physicist 4 7 [267][VII]
105 Db Dubnium Dubna, Russia, where the Joint Institute for Nuclear Research is located 5 7 [268][VII]
106 Sg Seaborgium Glenn T. Seaborg, American chemist 6 7 [269][VII]
107 Bh Bohrium Niels Bohr, Danish physicist 7 7 [270][VII]
108 Hs Hassium New Latin Hassia, 'Hesse' (a state in Germany) 8 7 [270][VII]
109 Mt Meitnerium Lise Meitner, Austrian physicist 9 7 [278][VII]
110 Ds Darmstadtium Darmstadt, Germany, where the element was first synthesised 10 7 [281][VII]
111 Rg Roentgenium Wilhelm Conrad Röntgen, German physicist 11 7 [282][VII]
112 Cn Copernicium Nicolaus Copernicus, Polish astronomer 12 7 [285][VII]
113 Nh Nihonium Japanese Nihon, 'Japan' (where the element was first synthesised) 13 7 [286][VII]
114 Fl Flerovium Flerov Laboratory of Nuclear Reactions, part of JINR, where the element was synthesised; itself named after Georgy Flyorov, Russian physicist 14 7 [289][VII]
115 Mc Moscovium Moscow Oblast, Russia, where the element was first synthesised 15 7 [290][VII]
116 Lv Livermorium Lawrence Livermore National Laboratory in Livermore, California, which collaborated with JINR on its synthesis 16 7 [293][VII]
117 Ts Tennessine Tennessee, United States 17 7 [294][VII]
118 Og Oganesson Yuri Oganessian, Russian physicist 18 7 [294][VII]

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. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al The isotopic composition of this element varies in some geological specimens, and the variation may exceed the uncertainty stated in the table.
  3. ^ a b c d e f g 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. ^ a b c d e f g h i j k l m n o The isotopic composition varies in terrestrial material such that a more precise atomic weight can not be given.
  5. ^ a b c d e f g h i j k l m 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. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al 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[edit]

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 symbol Name Atomic number Origin of symbol Why not used Refs
A Argon 18 A used for Argon until 1957. Current symbol is Ar. [nb 2] [6]
Ab Alabamine 85 Discredited claim to discovery of astatine. [nb 3] [7][8]
Ad Aldebaranium 70 Former name for ytterbium. [nb 3]
Am Alabamine 85 Discredited claim to discovery of astatine. The symbol is now used for americium. [nb 3] [7][9]
An Athenium 99 Proposed name for einsteinium. [nb 4]
Ao Ausonium 93 Discredited claim to discovery of neptunium. [nb 3] [7]
Az Azote 7 Former name for nitrogen. [nb 2]
Bo Boron 5 Current symbol is B. [nb 2]
Bv Brevium 91 Former name for protactinium. [nb 2]
Bz Berzelium 90 Baskerville wrongly believed berzelium to be a new element. Was actually thorium. [nb 4] [10]
Cb Columbium 41 Former name for niobium. [nb 2] [7][10]
Ch Chromium 24 Current symbol is Cr. [nb 2]
Cl Columbium 41 Former name for niobium. The symbol is now used for chlorine. [nb 2]
Cn Carolinium 90 Baskerville wrongly believed carolinium to be a new element. Was actually thorium. The symbol is now used for copernicium. [10]
Cp Cassiopeium 71 Former name for lutetium. [nb 2]
Cp Copernicium 112 Current symbol is Cn. [nb 2]
Ct Celtium 72 Discredited claim to discovery of hafnium. [nb 3]
Ct Centurium 100 Proposed name for fermium. [nb 4]
D Didymium 59/60 Mixture of the elements praseodymium and neodymium. Mosander wrongly believed didymium to be an element. [11]
Da Davyum 43 Discredited claim to discovery of technetium. [nb 3] [7]
Db Dubnium 104 Proposed name for rutherfordium. The symbol and name were instead used for element 105. [nb 2][nb 4] [7]
Di Didymium 59/60 Mixture of the elements praseodymium and neodymium. Mosander wrongly believed didymium to be an element. [11]
Ds Dysprosium 66 Current symbol is Dy. The symbol is now used for darmstadtium. [nb 2]
E Einsteinium 99 Current symbol is Es. [nb 2]
E Erbium 68 Current symbol is Er. [nb 2]
Ea Ekaaluminium 31 Name given by Mendeleev to an as of then undiscovered element. When discovered, gallium closely matched the prediction. [nb 4][nb 5]
Eb Ekaboron 21 Name given by Mendeleev to an as of then undiscovered element. When discovered, scandium closely matched the prediction. [nb 4][nb 5] [7]
El Ekaaluminium 31 Name given by Mendeleev to an as of then undiscovered element. When discovered, gallium closely matched the prediction. [nb 4][nb 5] [7]
Em Ekamanganese 43 Name given by Mendeleev to an as of then undiscovered element. When discovered, technetium closely matched the prediction. [nb 4][nb 5] [7]
Em Emanation 86 Also 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]
Em Emanium 89 Alternate name formerly proposed for actinium. [nb 4]
Es Ekasilicon 32 Name 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]
Es Esperium 94 Discredited claim to discovery of plutonium. The symbol is now used for einsteinium. [nb 3] [7]
Fa Francium 87 Current symbol is Fr. [nb 2]
Fl Florentium 61 Discredited claim to discovery of promethium. The symbol is now used for flerovium. [nb 3]
Fl Fluorine 9 Current symbol is F. The symbol is now used for flerovium. [nb 2]
Fr Florentium 61 Discredited claim to discovery of promethium. The symbol is now used for francium. [nb 3] [7]
G Glucinium 4 Former name for beryllium. [nb 2]
Gl Glucinium 4 Former name for beryllium. [nb 2] [7]
Ha Hahnium 105 Proposed name for dubnium. [nb 4]
Hn Hahnium 108 Proposed name for hassium. [nb 4] [7]
Hv Helvetium 85 Discredited claim to discovery of astatine. [nb 3] [10]
Hy Mercury 80 Hy from the Greek hydrargyrum for "liquid silver". Current symbol is Hg. [nb 2] [6]
I Iridium 77 Current symbol is Ir. The symbol is now used for iodine. [nb 2]
Il Illinium 61 Discredited claim to discovery of promethium. [nb 3] [7]
J Jodium 53 Former name for iodine. [nb 2]
Jg Jargonium 72 Discredited claim to discovery of hafnium. [nb 3] [7]
Jl Joliotium 105 Proposed name for dubnium. [nb 4] [7]
Ka Potassium 19 Current symbol is K. [nb 2]
Ku Kurchatovium 104 Proposed name for rutherfordium. [nb 4] [7]
L Lithium 3 Current symbol is Li. [nb 2]
Lw Lawrencium 103 Current symbol is Lr. [nb 2]
M Muriaticum 17 Former name for chlorine. [nb 2]
Ma Manganese 25 Current symbol is Mn. [nb 2]
Ma Masurium 43 Disputed claim to discovery of technetium. [nb 3] [7]
Md Mendelevium 97 Proposed name for berkelium. The symbol and name were later used for element 101. [nb 2][nb 4]
Ml Moldavium 87 Discredited claim to discovery of francium. [nb 3] [10]
Ms Magnesium 12 Current symbol is Mg. [nb 2]
Ms Masurium 43 Disputed claim to discovery of technetium. [nb 3]
Mv Mendelevium 101 Current symbol is Md. [nb 2]
Ng Norwegium 72 Discredited claim to discovery of hafnium. [nb 3]
No Norium 72 Discredited claim to discovery of hafnium. The symbol is now used for nobelium. [nb 3]
Np Nipponium 43 Discredited claim to discovery of technetium. The symbol is now used for neptunium. [nb 3] [7]
Ns Nielsbohrium 105 Proposed name for dubnium. [nb 4] [7]
Ns Nielsbohrium 107 Proposed name for bohrium. [nb 4] [7]
Nt Niton 86 Former name for radon. [nb 2] [7]
Ny Neoytterbium 70 Former name for ytterbium. [nb 2]
P Lead 82 Current symbol is Pb. The symbol is now used for phosphorus. [nb 2]
Pa Palladium 46 Current symbol is Pd. The symbol is now used for protactinium. [nb 2]
Pe Pelopium 41 Former name for niobium. [nb 2]
Pl Palladium 46 Current symbol is Pd. [nb 2]
Po Potassium 19 Current symbol is K. The symbol is now used for polonium. [nb 2]
R Rhodium 45 Current symbol is Rh. [nb 2]
Rd Radium 88 Current symbol is Ra. [nb 2]
Rf Rutherfordium 106 Proposed name for seaborgium. The symbol and name were instead used for element 104. [nb 2][nb 4] [7]
Ro Rhodium 45 Current symbol is Rh. [nb 2]
Sa Samarium 62 Current symbol is Sm. [nb 2] [7]
So Sodium 11 Current symbol is Na. [nb 2]
St Antimony 51 Current symbol is Sb. [nb 2]
St Tin 50 Current symbol is Sn. [nb 2]
Tn Tungsten 74 Current symbol is W. [nb 2]
Tr Terbium 65 Current symbol is Tb. [nb 2]
Tu Thulium 69 Current symbol is Tm. [nb 2]
Tu Tungsten 74 Current symbol is W. [nb 2]
Unb Unnilbium 102 Temporary name given to nobelium until it was permanently named by IUPAC. [nb 5]
Une Unnilennium 109 Temporary name given to meitnerium until it was permanently named by IUPAC. [nb 5]
Unh Unnilhexium 106 Temporary name given to seaborgium until it was permanently named by IUPAC. [nb 5]
Uno Unniloctium 108 Temporary name given to hassium until it was permanently named by IUPAC. [nb 5]
Unp Unnilpentium 105 Temporary name given to dubnium until it was permanently named by IUPAC. [nb 5]
Unq Unnilquadium 104 Temporary name given to rutherfordium until it was permanently named by IUPAC. [nb 5]
Uns Unnilseptium 107 Temporary name given to bohrium until it was permanently named by IUPAC. [nb 5]
Unt Unniltrium 103 Temporary name given to lawrencium until it was permanently named by IUPAC. [nb 5]
Unu Unnilunium 101 Temporary name given to mendelevium until it was permanently named by IUPAC. [nb 5]
Uub Ununbium 112 Temporary name given to copernicium until it was permanently named by IUPAC. [nb 5]
Uuh Ununhexium 116 Temporary name given to livermorium until it was permanently named by IUPAC. [nb 5]
Uun Ununnilium 110 Temporary name given to darmstadtium until it was permanently named by IUPAC. [nb 5]
Uuo Ununoctium 118 Temporary name given to oganesson until it was permanently named by IUPAC. [nb 5]
Uup Ununpentium 115 Temporary name given to moscovium until it was permanently named by IUPAC. [nb 5]
Uuq Ununquadium 114 Temporary name given to flerovium until it was permanently named by IUPAC. [nb 5]
Uus Ununseptium 117 Temporary name given to tennessine until it was permanently named by IUPAC. [nb 5]
Uut Ununtrium 113 Temporary name given to nihonium until it was permanently named by IUPAC. [nb 5]
Uuu Unununium 111 Temporary name given to roentgenium until it was permanently named by IUPAC. [nb 5]
Ur Uranium 92 Current symbol is U. [nb 2]
Vi Virginium 87 Discredited claim to discovery of francium. [nb 3] [7]
Vm Virginium 87 Discredited claim to discovery of francium. [nb 3] [7]
Va Vanadium 23 Current symbol is V. [nb 2]
Wo Tungsten 74 Current symbol is W. [nb 2]
X Xenon 54 Current symbol is Xe. The symbol is now used for halogens. [nb 2]
Yt Yttrium 39 Current symbol is Y. [nb 2] [7]

Pictographic symbols[edit]

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 symbol Original name Modern name Atomic number Origin of symbol
Hydrogen Hydrogen 1 Daltonian symbol circa 1808.
Carbon Carbon 6 Daltonian symbol circa 1808.
Azote Nitrogen 7 Daltonian symbol circa 1808.
Oxygen Oxygen 8 Daltonian symbol circa 1808.
Soda Sodium 11 Daltonian symbol circa 1808.
Magnesium Magnesium 12 Alchemical symbol.
Sulfur symbol 1.png Sulfur Sulfur 16 Alchemical symbol.
Sulfur symbol 2.png Pallas Sulfur 16 Alchemical symbol.
🜍 Sulfur Sulfur 16 Alchemical symbol.
Sulfur Sulfur 16 Daltonian symbol circa 1808.
Mars Iron 26 Alchemical symbol.
Iron Iron 26 Daltonian symbol circa 1808.
Marian star four-tenths.svg Stellae Fixae Copper 29 Pre–16th-century alchemical symbol.
Venus Copper 29 Alchemical symbol.
Copper symbol.svg Copper Copper 29 Alchemical symbol.
Copper Copper 29 Daltonian symbol circa 1808.
Zinc Zinc 30 Daltonian symbol circa 1808.
Arsenic alchemical symbol.svg Arsenic Arsenic 33 Alchemical symbol.
🜺 Arsenic Arsenic 33 Alchemical symbol.
Luna Silver 47 Alchemical symbol.
🜛 Silver Silver 47 Alchemical symbol.
Silver Silver 47 Daltonian symbol circa 1808.
Iupiter Tin 50 Alchemical symbol.
Antimony Antimony 51 Alchemical symbol.
☉☾ Platinum Platinum 78 Alchemical symbol.
Uranus Platinum 78 Alchemical symbol.
Sol Gold 79 Alchemical symbol from the 16th century.
Sol Gold 79 Alchemical symbol from 1700 through 1783.
🜚 Gold Gold 79 Alchemical symbol.
Pisces Mercury 80 Pre–16th-century alchemical symbol.
Neptunus Mercury 80 Alchemical symbol from the 17th century.
Mercurius Mercury 80 Alchemical symbol from 1700 through 1783.
Saturnus Lead 82 Alchemical symbol circa 1783.
Lead Lead 82 Daltonian symbol circa 1808.
Taurus Bismuth 83 Alchemical symbol.

Symbols for named isotopes[edit]

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.[12]

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.[13]

Chemical symbol Name Atomic number Origin of symbol
Ac Actinium 89 From 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.
AcA Actinium A 84 From actinium and A. Placeholder name given at one time to 215Po, an isotope of polonium identified in the decay chain of actinium.
AcB Actinium B 82 From actinium and B. Placeholder name given at one time to 211Pb, an isotope of lead identified in the decay chain of actinium.
AcC Actinium C 83 From actinium and C. Placeholder name given at one time to 211Bi, an isotope of bismuth identified in the decay chain of actinium.
AcC' Actinium C' 84 From 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" 81 From actinium and C". Placeholder name given at one time to 207Tl, an isotope of thallium identified in the decay chain of actinium.
AcK Actinium K 87 Name given at one time to 223Fr, an isotope of francium identified in the decay chain of actinium.
AcU Actino-uranium 92 Name given at one time to 235U, an isotope of uranium.
AcX Actinium X 88 Name given at one time to 223Ra, an isotope of radium identified in the decay chain of actinium.
An Actinon 86 From actinium and emanation. Name given at one time to 219Rn, an isotope of radon identified in the decay chain of actinium.
D Deuterium 1 From the Greek deuteros. Name given to 2H.
Io Ionium 90 Name given to 230Th, an isotope of thorium identified in the decay chain of uranium.
MsTh1 Mesothorium 1 88 Name given at one time to 228Ra, an isotope of radium.
MsTh2 Mesothorium 2 89 Name given at one time to 228Ac, an isotope of actinium.
Pa Protactinium 91 From 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.
Ra Radium 88 From 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.
RaA Radium A 84 From radium and A. Placeholder name given at one time to 218Po, an isotope of polonium identified in the decay chain of radium.
RaB Radium B 82 From radium and B. Placeholder name given at one time to 214Pb, an isotope of lead identified in the decay chain of radium.
RaC Radium C 83 From radium and C. Placeholder name given at one time to 214Bi, an isotope of bismuth identified in the decay chain of radium.
RaC' Radium C' 84 From 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" 81 From radium and C". Placeholder name given at one time to 210Tl, an isotope of thallium identified in the decay chain of radium.
RaD Radium D 82 From radium and D. Placeholder name given at one time to 210Pb, an isotope of lead identified in the decay chain of radium.
RaE Radium E 83 From radium and E. Placeholder name given at one time to 210Bi, an isotope of bismuth identified in the decay chain of radium.
RaE" Radium E" 81 From radium and E". Placeholder name given at one time to 206Tl, an isotope of thallium identified in the decay chain of radium.
RaF Radium F 84 From radium and F. Placeholder name given at one time to 210Po, an isotope of polonium identified in the decay chain of radium.
RdAc Radioactinium 90 Name given at one time to 227Th, an isotope of thorium.
RdTh Radiothorium 90 Name given at one time to 228Th, an isotope of thorium.
Rn Radon 86 From 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.
T Tritium 1 From the Greek tritos. Name given to 3H.
Th Thorium 90 After Thor. Name restricted at one time to 232Th, an isotope of thorium. This named isotope later became the official name for element 90.
ThA Thorium A 84 From thorium and A. Placeholder name given at one time to 216Po, an isotope of polonium identified in the decay chain of thorium.
ThB Thorium B 82 From thorium and B. Placeholder name given at one time to 212Pb, an isotope of lead identified in the decay chain of thorium.
ThC Thorium C 83 From thorium and C. Placeholder name given at one time to 212Bi, an isotope of bismuth identified in the decay chain of thorium.
ThC' Thorium C' 84 From 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" 81 From thorium and C". Placeholder name given at one time to 208Tl, an isotope of thallium identified in the decay chain of thorium.
ThX Thorium X 88 Name given at one time to 224Ra, an isotope of radium identified in the decay chain of thorium.
Tn Thoron 86 From thorium and emanation. Name given at one time to 220Rn, an isotope of radon identified in the decay chain of thorium.
UI Uranium I 92 Name given at one time to 238U, an isotope of uranium.
UII Uranium II 92 Name given at one time to 234U, an isotope of uranium.
UX1 Uranium X1 90 Name given at one time to 234Th, an isotope of thorium identified in the decay chain of uranium.
UX2 Uranium X2 91 Name given at one time to 234mPa, an isotope of protactinium identified in the decay chain of uranium.
UY Uranium Y 90 Name given at one time to 231Th, an isotope of thorium identified in the decay chain of uranium.
UZ Uranium Z 91 Name given at one time to 234Pa, an isotope of protactinium identified in the decay chain of uranium.

Other symbols[edit]

See also Skeletal formula § Pseudoelement symbols.

General:

From organic chemistry:

Exotic atoms:

See also[edit]

Notes[edit]

  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. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba Name changed due to a standardization of, modernization of, or update to older formerly-used symbol.
  3. ^ a b c d e f g h i j k l m n o p q r s t Name designated by discredited/disputed claimant.
  4. ^ a b c d e f g h i j k l m n o p q r Name proposed prior to discovery/creation of element or prior to official re-naming of a placeholder name.
  5. ^ a b c d e f g h i j k l m n o p q r s t u v w Temporary placeholder name.

References[edit]

  1. ^ "IUPAC Provisional Recommendations: IR-3: Elements and Groups of Elements" (PDF). IUPAC. March 2004.
  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. ^ a b Holden, N. E. (12 March 2004). "History of the Origin of the Chemical Elements and Their Discoverers". National Nuclear Data Center.
  7. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac 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. ^ http://www.encyclopediaofalabama.org/article/h-1672
  10. ^ a b c d e Fontani, Marco; Costa, Mariagrazia; Orna, Mary Virginia (2014). The Lost Elements: The Periodic Table's Shadow Side. Oxford University Press. ISBN 9780199383344.
  11. ^ a b Praseodymium. was.chemistryexplained.com.
  12. ^ IUPAC. "Isotopically Modified Compounds". IUPAC. Retrieved 31 March 2015.
  13. ^ 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.
  14. ^ 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[edit]