Standard atomic weights 1981
(Scaled to the relative atomic mass 12C = 12)
| Name | Symbol |
Atomic
Number |
Atomic Weight |
| Actinium |
Ac
|
89
|
227.0278 |
| Aluminum |
Al
|
13
|
26.98154 |
| Americium |
Am
|
95
|
(243) |
| Antimony (Stibium) |
Sb
|
51
|
121.75 ± 3 |
| Argon |
Ar
|
18
|
39.948 |
| Arsenic |
As
|
33
|
74.9216 |
| Astatine |
At
|
85
|
(210) |
| Barium |
Ba
|
56
|
137.33 |
| Berkelium |
Bk
|
97
|
(247) |
| Beryllium |
Be
|
4
|
9.01218 |
| Bismuth |
Bi
|
83
|
208.9804 |
| Boron |
B
|
5
|
10.81 |
| Bromine |
Br
|
35
|
79.904 |
| Cadmium |
Cd
|
48
|
112.41 |
| Cesium |
Cs
|
55
|
132.9054 |
| Calcium |
Ca
|
20
|
40.08 |
| Californium |
Cf
|
98
|
(251) |
| Carbon |
C
|
6
|
12.011 |
| Cerium |
Ce
|
58
|
140.12 |
| Chlorine |
CI
|
17
|
35.453 |
| Chromium |
Cr
|
24
|
51.996 |
| Cobalt |
Co
|
27
|
58.9332 |
| Copper |
Cu
|
29
|
63.546 ±3 |
| Curium |
Cm
|
96
|
(247) |
| Dysprosium |
Dy
|
66
|
162.50 ± 3 |
| Einsteinium |
Es
|
99
|
(252) |
| Erbium |
Er
|
68
|
167.26 ± 3 |
| Europium |
Eu
|
63
|
151.96 |
| Fermium |
Fm
|
100
|
(257) |
| Fluorine |
F
|
9
|
18.998403 |
| Francium |
Fr
|
87
|
(223) |
| Gadolinium |
Gd
|
64
|
157.25 ± 3 |
| Gallium |
Ga
|
31
|
69.72 |
| Germanium |
Ge
|
32
|
72.59 ± 3 |
| Gold |
Au
|
79
|
196.9665 |
| Hafnium |
Hf
|
72
|
178.49 ± 3 |
| Helium |
He
|
2
|
4.00260 |
| Holmium |
Ho
|
67
|
164.9304 |
| Hydrogen |
H
|
1
|
1.00794 7 |
| Indium |
In
|
49
|
114.82 |
| Iodine |
I
|
53
|
126.9045 |
| Iridium |
Ir
|
77
|
192.22 ± 3 |
| Iron |
Fe
|
26
|
55.847 ± 3 |
| Krypton |
Kr
|
36
|
83.80 |
| Lanthanum |
La
|
57
|
138.9055 ± 3 |
| Lawrencium |
Lr
|
103
|
(260) |
| Lead |
Pb
|
82
|
207.2 |
| Lithium |
Li
|
3
|
6.941 ± 3 |
| Lutetium |
Lu
|
71
|
174.967 |
| Magnesium |
Mg
|
12
|
24.305 |
| Manganese |
Mn
|
25
|
54.9380 |
| Mendelevium |
Md
|
101
|
(258) |
| Mercury |
Hg
|
80
|
200.59 ± 3 |
| Molybdenum |
Mo
|
42
|
95.94 |
| Neodymium |
Nd
|
60
|
144.24 ± 3 |
| Neon |
Ne
|
10
|
20.179 |
| Neptunium |
Np
|
93
|
237.0482 |
| Nickel |
Ni
|
28
|
58.69 |
| Niobium |
Nb
|
41
|
92.9064 |
| Nitrogen |
N
|
7
|
14.0067 |
| Nobelium |
No
|
102
|
(259) |
| Osmium |
Os
|
76
|
190.2 |
| Oxygen |
0
|
8
|
15.9994 ± 3 |
| Palladium |
Pd
|
46
|
106.42 |
| Phosphorus |
P
|
15
|
30.97376 |
| Platinum |
Pt
|
78
|
195.08 ± 3 |
| Plutonium |
Pu
|
94
|
(244) |
| Polonium |
Po
|
84
|
(209) |
| Potassium (Kalium) |
K
|
19
|
39.0983 |
| Praseodymium |
Pr
|
59
|
140.9077 |
| Promethium |
Pm
|
61
|
(145) |
| Protactinium |
Pa
|
91
|
231.0359 |
| Radium |
Ra
|
88
|
226.0254 |
| Radon |
Rn
|
86
|
(222) |
| Rhenium |
Re
|
75
|
186.207 |
| Rhodium |
Rh
|
45
|
102.9055 |
| Rubidium |
Rb
|
37
|
85.4678 3 |
| Ruthenium |
Ru
|
44
|
101.07 ± 3 |
| Samarium |
Sm
|
62
|
150.36 ± 3 |
| Scandium |
Sc
|
21
|
44.9559 |
| Selenium |
Se
|
34
|
78.96 ± 3 |
| Silicon |
Si
|
14
|
28.0855 ± 3 |
| Silver |
Ag
|
47
|
107.8682 ± 3 |
| Sodium (Natrium) |
Na
|
11
|
22.98977 |
| Strontium |
Sr
|
38
|
87.62 |
| Sulfur |
S
|
16
|
32.06 |
| Tantalum |
Ta
|
73
|
180.9479 |
| Technetium |
Tc
|
43
|
(98) |
| Tellurium |
Te
|
52
|
127.60 ± 3 |
| Terbium |
Th
|
65
|
158.9254 |
| Thallium |
Tl
|
81
|
204.383 |
| Thorium |
Th
|
90
|
232.0381 |
| Thulium |
Tm
|
69
|
168.9342 |
| Tin |
Sn
|
50
|
118.69 3 |
| Titanium |
Ti
|
22
|
47.88 3 |
| Tungsten(Wolfram) |
W
|
74
|
183.85 3 |
| Uranium |
U
|
92
|
238.0289 |
| Vanadium |
V
|
23
|
50.9415 |
| Xenon |
Xe
|
54
|
131.29 ± 3 |
| Ytterbium |
Yb
|
70
|
173.04 |
| Yttrium |
Y
|
39
|
88.91 |
| Zinc |
Zn;
|
30
|
65.38 |
| Zirconium |
Zr
|
40
|
91.22 |