These values are current as of August, 2011.
The elements are listed by increasing atomic number.
Atomic Number - Symbol - Name - Atomic Weight
1 H - Hydrogen - [1.007 84; 1.008 11]
2 He - Helium - 4.002 602(2)
3 Li - Lithium - [6.938; 6.997]
4 Be - Beryllium - 9.012 182(3)
5 B - Boron - [10.806; 10.821]
6 C - Carbon - [12.0096; 12.0116]
7 N - Nitrogen - [14.006 43; 14.007 28]
8 O - Oxygen - [15.999 03; 15.999 77]
9 F - Fluorine - 18.998 4032(5)
10 Ne - Neon - 20.1797(6)
11 Na - Sodium - 22.989 769 28(2)
12 Mg - Magnesium - 24.3050(6)
13 Al - Aluminium - 26.981 5386(8)
14 Si - Silicon - [28.084; 28.086]
15 P - Phosphorus - 30.973 762(2)
16 S - Sulfur - [32.059; 32.076]
17 Cl - Chlorine - [35.446; 35.457]
18 Ar - Argon - 39.948(1)
19 K - Potassium - 39.0983(1)
20 Ca - Calcium - 40.078(4)
21 Sc - Scandium - 44.955 912(6)
22 Ti - Titanium - 47.867(1)
23 V - Vanadium - 50.9415(1)
24 Cr - Chromium - 51.9961(6)
25 Mn - Manganese - 54.938 045(5)
26 Fe - Iron - 55.845(2)
27 Co - Cobalt - 58.933 195(5)
28 Ni - Nickel 58.6934(4)
29 Cu - Copper - 63.546(3)
30 Zn - Zinc - 65.38(2)
31 Ga - Gallium - 69.723(1)
32 Ge - Germanium - 72.63(1)
33 As - Arsenic - 74.921 60(2)
34 Se - Selenium - 78.96(3)
35 Br - Bromine - 79.904(1)
36 Kr - Krypton - 83.798(2)
37 Rb - Rubidium - 85.4678(3)
38 Sr - Strontium - 87.62(1)
39 Y - Yttrium - 88.905 85(2)
40 Zr - Zirconium - 91.224(2)
41 Nb - Niobium - 92.906 38(2)
42 Mo - Molybdenum - 95.96(2)
43 Tc - Technetium - <98>
44 Ru - Ruthenium - 101.07(2)
45 Rh - Rhodium - 102.905 50(2)
46 Pd - Palladium - 106.42(1)
47 Ag - Silver - 107.8682(2)
48 Cd - Cadmium - 112.411(8)
49 In - Indium - 114.818(3)
50 Sn - Tin - 118.710(7)
51 Sb - Antimony - 121.760(1)
52 Te - Tellurium - 127.60(3)
53 I - Iodine - 126.904 47(3)
54 Xe - Xenon - 131.293(6)
55 Cs - Cesium - 132.905 4519(2)
56 Ba - Barium - 137.327(7)
57 La - Lanthanum - 138.905 47(7)
58 Ce - Cerium - 140.116(1)
59 Pr - Praseodymium - 140.907 65(2)
60 Nd - Neodymium - 144.242(3)
61 Pm - Promethium - <145>
62 Sm - Samarium - 150.36(2)
63 Eu - Europium - 151.964(1)
64 Gd - Gadolinium - 157.25(3)
65 Tb - Terbium - 158.925 35(2)
66 Dy - Dysprosium - 162.500(1)
67 Ho - Holmium - 164.930 32(2)
68 Er - Erbium - 167.259(3)
69 Tm - Thulium - 168.934 21(2)
70 Yb - Ytterbium - 173.054(5)
71 Lu - Lutetium - 174.9668(1)
72 Hf - Hafnium - 178.49(2)
73 Ta - Tantalum - 180.947 88(2)
74 W - Tungsten - 183.84(1)
75 Re - Rhenium - 186.207(1)
76 Os - Osmium - 190.23(3)
77 Ir - Iridium - 192.217(3)
78 Pt - Platinum - 195.084(9)
79 Au - Gold - 196.966 569(4)
80 Hg - Mercury - 200.59(2)
81 Tl - Thallium - [204.382; 204.385]
82 Pb - Lead - 207.2(1)
83 Bi - Bismuth - 208.980 40(1)
84 Po - Polonium - <209>
85 At - Astatine - <210>
86 Rn - Radon - <222>
87 Fr - Francium - <223>
88 Ra - Radium - <226>
89 Ac - Actinium - <227>
90 Th - Thorium - 232.038 06(2)
91 Pa - Protactinium - 231.035 88(2)
92 U - Uranium - 238.028 91(3)
93 Np - Neptunium - <237>
94 Pu - Plutonium - <244>
95 Am - Americium - <243>
96 Cm - Curium - <247>
97 Bk - Berkelium - <247>
98 Cf - Californium - <251>
99 Es - Einsteinium - <252>
100 Fm - Fermium - <257>
101 Md - Mendelevium - <258>
102 No - Nobelium - <259>
103 Lr - Lawrencium - <262>
104 Rf - Rutherfordium - <267>
105 Db - Dubnium - <268>
106 Sg - Seaborgium - <271>
107 Bh - Bohrium - <272>
108 Hs - Hassium - <270>
109 Mt - Meitnerium - <276>
110 Ds - Darmstadtium - <281>
111 Rg - Roentgenium - <280>
112 Cn - Copernicium - <285>
113 Uut - Ununtrium - <284>
114 Uuq - Ununquadium - <289>
115 Uup - Ununpentium - <288>
116 Uuh - Ununhexium - <293>
118 Uuo - Ununoctium - <294>
Values given in chevron brackets (e.g., Fm <257>) are the mass numbers of the longest-lived isotope of elements that do not have stable nuclides. However, atomic weights are provided for Th, Pa, and U because these elements have a characteristic abundance in the earth's crust.
For detailed element facts, consult the Periodic Table for individual elements.
