The atomic weight of an atom is the total weight of an atom. It is also called relative atomic mass.
In the following table, the atomic weights of all the Periodic Table elements are given based on carbon 12 = 12.0000. The numbers in the parentheses represent the mass numbers of the most stable known isotope.
Table of Atomic Weights of All the Elements in the Periodic Table
Atomic Number | Symbol   | Atom Name | Relative Atomic Mass (Atomic Weight) |
1 | H | Hydrogen | 1.00797 |
2 | He | Helium | 4.003 |
3 | Li | Lithium | 6.939 |
4 | Be | Beryllium | 9.012 |
5 | B | Boron | 10.811 |
6 | C | Carbon | 12.01115 |
7 | N | Nitrogen | 14.0067 |
8 | O | Oxygen | 15.9994 |
9 | F | Fluorine | 18.993 |
10 | Ne | Neon | 20.183 |
11 | Na | Sodium | 22.9898 Â Â |
12 | Mg | Magnesium | 24.312 |
13 | Al | Aluminium | 26.982 |
14 | Si | Silicon | 28.086 |
15 | P | Phosphorus | 30.9738 |
16 | S | Sulfur | 32.064 |
17 | Cl | Chlorine | 35.453 |
18 | Ar | Argon | 39.948 |
19 | K | Potassium | 39.102 |
20 | Ca | Calcium | 40.08 |
21 | Sc | Scandium | 44.96 |
22 | Ti | Titanium | 47.90 |
23 | V | Vanadium | 50.942 |
24 | Cr | Chromium | 51.996 |
25 | Mn | Manganese | 54.938 |
26 | Fe | Iron | 55.847 |
27 | Co | Cobalt | 58.933 |
28 | Ni | Nickel | 58.71 |
29 | Cu | Copper | 63.54 |
30 | Zn | Zinc | 65.39(2) |
31 | Ga | Gallium | 69.723(4) |
32 | Ge | Germanium | 72.61(2) |
33 | As | Arsenic | 74.921 59(2) |
34 | Se | Selenium | 78.96(3) |
35 | Br | Bromine | 79.904(1) |
36 | Kr | Krypton | 83.80(1) |
37 | Rb | Rubidium | 85.467 8(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 | 95.94(1) |
43 | Tc | Technetium | [99]* |
44 | Ru | Ruthenium | 101.07(2) |
45 | Rh | Rhodium | 102.905 50(3) |
46 | Pd | Palladium | 106.42(1) |
47 | Ag | Silver | 107.868 2(2) |
48 | Cd | Cadmium | 112.411(8) |
49 | In | Indium | 114.82(1) |
50 | Sn | Tin | 118.710(7) |
51 | Sb | Antimony | 121.75(3) |
52 | Te | Tellurium | 127.60(3) |
53 | I | Iodine | 126.904 47(3) |
54 | Xe | Xenon | 131.29(2) |
55 | Cs | Caesium | 132.905 43(5) |
56 | Ba | Barium | 137.327(7) |
57 | La | Lanthanum | 138.905 5(2) |
58 | Ce | Cerium | 140.115(4) |
59 | Pr | Praseodymium   | 140.907 65(3) |
60 | Nd | Neodymium | 144.24(3) |
61 | Pm | Promethium | [147]* |
62 | Sm | Samarium | 150.36(3) |
63 | Eu | Europium | 151.965(9) |
64 | Gd | Gadolinium | 157.25(3) |
65 | Tb | Terbium | 158.925 34(3) |
66 | Dy | Dysprosium | 162.50(3) |
67 | Ho | Holmium | 164.930 32(3) |
68 | Er | Erbium | 167.26(3) |
69 | Tm | Thulium | 168.934 21(3) |
70 | Yb | Ytterbium | 173.04(3) |
71 | Lu | Lutetium | 174.967(1) |
72 | Hf | Hafnium | 178.49(2) |
73 | Ta | Tantalum | 180.947 9(1) |
74 | W | Tungsten | 183.85(3) |
75 | Re | Rhenium | 186.207(1) |
76 | Os | Osmium | 190.2(1) |
77 | Ir | Iridium | 192.22(3) |
78 | Pt | Platinum | 195.08(3) |
79 | Au | Gold | 196.966 54(3) |
80 | Hg | Mercury | 200.59(3) |
81 | Tl | Thallium | 204.383 3(2) |
82 | Pb | Lead | 207.2(1) |
83 | Bi | Bismuth | 208.980 37(3) |
84 | Po | Polonium | [210]* |
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 1(1) |
91 | Pa | Protactinium | 231.035 88(2) |
92 | U | Uranium | 238.028 9(1) |
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 | [270]* |
106 | Sg | Seaborgium | [269]* |
107 | Bh | Bohrium | [270]* |
108 | Hs | Hassium | [270]* |
109 | Mt | Meitnerium | [278]* |
110 | Ds | Darmstadtium | [281]* |
111 | Rg | Roentgenium | [281]* |
112 | Cn | Copernicium | [285]* |
113 | Nh | Nihonium | [286]* |
114 | Fl | Flerovium | [289]* |
115 | Mc | Moscovium | [289]* |
116 | Lv | Livermorium | [293]* |
117 | Ts | Tennessine | [293]* |
118 | Og | Oganesson | [294]* |
Reference:
- Pure Appl. Chem. 52 (1980) 2349-2384
- Pure Appl. Chem. 56, (1984) 695-768
- Pure Appl. Chem. 58 (1986) 1677-1692
- Pure Appl. Chem. 56 (1984) 675-694
- IUPAC: Pure and Applied Chemistry (1994) 66, 2433-2444.Â