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List of elements by atomic mass



This is a list of chemical elements, sorted by relative atomic mass, or more precisely the standard atomic weights, (most stable isotope for artificial elements) and color coded according to type of element. Each element's atomic number, name, element symbol, and group and period numbers on the periodic table are given. The number in parenthesis gives the uncertainty in the "concise notation" defined in the IUPAC reference "whereby standard uncertainty is given in parenthesis next to the least significant digits to which it applies", e.g., 1.00794(7) stands for 1.00794 ± 0.00007. For artificial elements the nucleon count of the most stable isotope is listed brackets [] as the atomic mass.

Atomic Number Name Symbol Relative Atomic Mass Group Period
1 Hydrogen H 1.00794(7)2 3 4 1 1
2 Helium He 4.002602(2)2 4 18 1
3 Lithium Li 6.941(2)2 3 4 5 1 2
4 Beryllium Be 9.012182(3) 2 2
5 Boron B 10.811(7)2 3 4 13 2
6 Carbon C 12.0107(8)2 4 14 2
7 Nitrogen N 14.0067(2)2 4 15 2
8 Oxygen O 15.9994(3)2 4 16 2
9 Fluorine F 18.9984032(5) 17 2
10 Neon Ne 20.1797(6)2 3 18 2
11 Sodium (Natrium) Na 22.98976928(2) 1 3
12 Magnesium Mg 24.3050(6) 2 3
13 Aluminium (Aluminum) Al 26.9815386(8) 13 3
14 Silicon Si 28.0855(3)4 14 3
15 Phosphorus P 30.973762(2) 15 3
16 Sulfur S 32.065(5)2 4 16 3
17 Chlorine Cl 35.453(2)2 3 4 17 3
19 Potassium (Kalium) K 39.0983(1) 1 4
18 Argon Ar 39.948(1)2 4 18 3
20 Calcium Ca 40.078(4)2 2 4
21 Scandium Sc 44.955912(6) 3 4
22 Titanium Ti 47.867(1) 4 4
23 Vanadium V 50.9415(1) 5 4
24 Chromium Cr 51.9961(6) 6 4
25 Manganese Mn 54.938045(5) 7 4
26 Iron (Ferrum) Fe 55.845(2) 8 4
28 Nickel Ni 58.6934(2) 10 4
27 Cobalt Co 58.933195(5) 9 4
29 Copper (Cuprum) Cu 63.546(3)4 11 4
30 Zinc Zn 65.409(4) 12 4
31 Gallium Ga 69.723(1) 13 4
32 Germanium Ge 72.64(1) 14 4
33 Arsenic As 74.92160(2) 15 4
34 Selenium Se 78.96(3)4 16 4
35 Bromine Br 79.904(1) 17 4
36 Krypton Kr 83.798(2)2 3 18 4
37 Rubidium Rb 85.4678(3)2 1 5
38 Strontium Sr 87.62(1)2 4 2 5
39 Yttrium Y 88.90585(2) 3 5
40 Zirconium Zr 91.224(2)2 4 5
41 Niobium Nb 92.906 38(2) 5 5
42 Molybdenum Mo 95.94(2)2 6 5
43 Technetium Tc [98]1 7 5
44 Ruthenium Ru 101.07(2)2 8 5
45 Rhodium Rh 102.905 50(2) 9 5
46 Palladium Pd 106.42(1)2 10 5
47 Silver (Argentum) Ag 107.8682(2)2 11 5
48 Cadmium Cd 112.411(8)2 12 5
49 Indium In 114.818(3) 13 5
50 Tin (Stannum) Sn 118.710(7)2 14 5
51 Antimony (Stibium) Sb 121.760(1)2 15 5
52 Tellurium Te 127.60(3)2 16 5
53 Iodine I 126.904 47(3) 17 5
54 Xenon Xe 131.293(6)2 3 18 5
55 Caesium (Cesium) Cs 132.9054519(2) 1 6
56 Barium Ba 137.327(7) 2 6
57 Lanthanum La 138.90547(7)2 n/a 6
58 Cerium Ce 140.116(1)2 n/a 6
59 Praseodymium Pr 140.90765(2) n/a 6
60 Neodymium Nd 144.242(3)2 n/a 6
61 Promethium Pm [145]1 n/a 6
62 Samarium Sm 150.36(2)2 n/a 6
63 Europium Eu 151.964(1)2 n/a 6
64 Gadolinium Gd 157.25(3)2 n/a 6
65 Terbium Tb 158.92535(2) n/a 6
66 Dysprosium Dy 162.500(1)2 n/a 6
67 Holmium Ho 164.930 32(2) n/a 6
68 Erbium Er 167.259(3)2 n/a 6
69 Thulium Tm 168.93421(2) n/a 6
70 Ytterbium Yb 173.04(3)2 n/a 6
71 Lutetium Lu 174.967(1)2 3 6
72 Hafnium Hf 178.49(2) 4 6
73 Tantalum Ta 180.94788(2) 5 6
74 Tungsten (Wolfram) W 183.84(1) 6 6
75 Rhenium Re 186.207(1) 7 6
76 Osmium Os 190.23(3)2 8 6
77 Iridium Ir 192.217(3) 9 6
78 Platinum Pt 195.084(9) 10 6
79 Gold (Aurum) Au 196.966569(4) 11 6
80 Mercury (Hydrargyrum) Hg 200.59(2) 12 6
81 Thallium Tl 204.3833(2) 13 6
82 Lead (Plumbum) Pb 207.2(1)2 4 14 6
83 Bismuth Bi 208.98040(1) 15 6
84 Polonium Po [210]1 16 6
85 Astatine At [210]1 17 6
86 Radon Rn [220]1 18 6
87 Francium Fr [223]1 1 7
88 Radium Ra [226]1 2 7
89 Actinium Ac [227]1 n/a 7
91 Protactinium Pa 231.03588(2)1 n/a 7
90 Thorium Th 232.03806(2)1 2 n/a 7
93 Neptunium Np [237]1 n/a 7
92 Uranium U 238.02891(3)1 2 3 n/a 7
95 Americium Am [243]1 n/a 7
94 Plutonium Pu [244]1 n/a 7
96 Curium Cm [247]1 n/a 7
97 Berkelium Bk [247]1 n/a 7
98 Californium Cf [251]1 n/a 7
99 Einsteinium Es [252]1 n/a 7
100 Fermium Fm [257]1 n/a 7
101 Mendelevium Md [258]1 n/a 7
102 Nobelium No [259]1 n/a 7
103 Lawrencium Lr [262]1 3 7
104 Rutherfordium Rf [261]1 4 7
105 Dubnium Db [262]1 5 7
106 Seaborgium Sg [266]1 6 7
107 Bohrium Bh [264]1 7 7
108 Hassium Hs [277]1 8 7
109 Meitnerium Mt [268]1 9 7
110 Darmstadtium Ds [271]1 10 7
111 Roentgenium Rg [272]1 11 7
112 Ununbium Uub [285]1 12 7
113 Ununtrium Uut [284]1 13 7
114 Ununquadium Uuq [289]1 14 7
115 Ununpentium Uup [288]1 15 7
116 Ununhexium Uuh [292]1 16 7
118 Ununoctium Uuo [294]1 18 7

Notes

  • Note 1: 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, three elements, Thorium, Protactinium, and Uranium, have a characteristic terrestrial isotopic composition, and thus their standard atomic weights are given.
  • Note 2: The isotopic composition of this element varies in some geological specimens, and the variation may exceed the uncertainty stated in the table.
  • Note 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.
  • Note 4: The isotopic composition varies in terrestrial material such that a more precise atomic weight can not be given.
  • Note 5: 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.

References

  • 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.
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "List_of_elements_by_atomic_mass". A list of authors is available in Wikipedia.
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