Appendix A Atomic Masses
Atomic Number, Z | Name | Atomic Mass Number, A | Symbol | Atomic Mass (u) | Percent Abundance or Decay Mode | Half-life, t1/2 |
---|---|---|---|---|---|---|
0 | neutron | 1 | n | 1.008 665 | β- | 10.37 min |
1 | Hydrogen | 1 | 1H | 1.007 825 | 99.985% | |
Deuterium | 2 | 2H or D | 2.014 102 | 0.015% | ||
Tritium | 3 | 3H or T | 3.016 050 | β- | 12.33 y | |
2 | Helium | 3 | 3He | 3.016 030 | 1.38×10-4% | |
4 | 4He | 4.002 603 | ≈100% | |||
3 | Lithium | 6 | 6Li | 6.015 121 | 7.5% | |
7 | 7Li | 7.016 003 | 92.5% | |||
4 | Beryllium | 7 | 7Be | 7.016 928 | EC | 53.29 d |
9 | 9Be | 9.012 182 | 100% | |||
5 | Boron | 10 | 10B | 10.012 937 | 19.9% | |
11 | 11B | 11.009 305 | 80.1% | |||
6 | Carbon | 11 | 11C | 11.011 432 | EC, β+ | |
12 | 12C | 12.000 000 | 98.90% | |||
13 | 13C | 13.003 355 | 1.10% | |||
14 | 14C | 14.003 241 | β- | 5730 y | ||
7 | Nitrogen | 13 | 13N | 13.005 738 | β+ | 9.96 min |
14 | 14N | 14.003 074 | 99.63% | |||
15 | 15N | 15.000 108 | 0.37% | |||
8 | Oxygen | 15 | ![]() |
15.003 065 | EC, β+ | 122 s |
16 | ![]() |
15.994 915 | 99.76% | |||
18 | ![]() |
17.999 160 | 0.200% | |||
9 | Fluorine | 18 | ![]() |
18.000 937 | EC, β+ | 1.83 h |
19 | ![]() |
18.998 403 | 100% | |||
10 | Neon | 20 | ![]() |
19.992 435 | 90.51% | |
22 | ![]() |
21.991 383 | 9.22% | |||
11 | Sodium | 22 | ![]() |
21.994 434 | β+ | 2.602 y |
23 | ![]() |
22.989 767 | 100% | |||
24 | ![]() |
23.990 961 | β- | 14.96 h | ||
12 | Magnesium | 24 | ![]() |
23.985 042 | 78.99% | |
13 | Aluminum | 27 | ![]() |
26.981 539 | 100% | |
14 | Silicon | 28 | ![]() |
27.976 927 | 92.23% | 2.62h |
31 | ![]() |
30.975 362 | β- | |||
15 | Phosphorus | 31 | ![]() |
30.973 762 | 100% | |
32 | ![]() |
31.973 907 | β- | 14.28 d | ||
16 | Sulfur | 32 | ![]() |
31.972 070 | 95.02% | |
35 | ![]() |
34.969 031 | β- | 87.4 d | ||
17 | Chlorine | 35 | ![]() |
34.968 852 | 75.77% | |
37 | ![]() |
36.965 903 | 24.23% | |||
18 | Argon | 40 | ![]() |
39.962 384 | 99.60% | |
19 | Potassium | 39 | ![]() |
38.963 707 | 93.26% | |
40 | ![]() |
39.963 999 | 0.0117%, EC, β- | ![]() |
||
20 | Calcium | 40 | ![]() |
39.962 591 | 96.94% | |
21 | Scandium | 45 | ![]() |
44.955 910 | 100% | |
22 | Titanium | 48 | ![]() |
47.947 947 | 73.8% | |
23 | Vanadium | 51 | ![]() |
50.943 962 | 99.75% | |
24 | Chromium | 52 | ![]() |
51.940 509 | 83.79% | |
25 | Manganese | 55 | ![]() |
54.938 047 | 100% | |
26 | Iron | 56 | ![]() |
55.934 939 | 91.72% | |
27 | Cobalt | 59 | ![]() |
58.933 198 | 100% | |
60 | ![]() |
59.933 819 | β- | 5.271 y | ||
28 | Nickel | 58 | ![]() |
57.935 346 | 68.27% | |
60 | ![]() |
59.930 788 | 26.10% | |||
29 | Copper | 63 | ![]() |
62.939 598 | 69.17% | |
65 | ![]() |
64.927 793 | 30.83% | |||
30 | Zinc | 64 | ![]() |
63.929 145 | 48.6% | |
66 | ![]() |
65.926 034 | 27.9% | |||
31 | Gallium | 69 | ![]() |
68.925 580 | 60.1% | |
32 | Germanium | 72 | ![]() |
71.922 079 | 27.4% | |
74 | ![]() |
73.921 177 | 36.5% | |||
33 | Arsenic | 75 | ![]() |
74.921 594 | 100% | |
34 | Selenium | 80 | ![]() |
79.916 520 | 49.7% | |
35 | Bromine | 79 | ![]() |
78.918 336 | 50.69% | |
36 | Krypton | 84 | ![]() |
83.911 507 | 57.0% | |
37 | Rubidium | 85 | ![]() |
84.911 794 | 72.17% | |
38 | Strontium | 86 | ![]() |
85.909 267 | 9.86% | |
88 | ![]() |
87.905 619 | 82.58% | |||
90 | ![]() |
89.907 738 | β- | 28.8 y | ||
39 | Yttrium | 89 | ![]() |
88.905 849 | 100% | |
90 | ![]() |
89.907 152 | β- | 64.1 h | ||
40 | Zirconium | 90 | ![]() |
89.904 703 | 51.45% | |
41 | Niobium | 93 | ![]() |
92.906 377 | 100% | |
42 | Molybdenum | 98 | ![]() |
97.905 406 | 24.13% | |
43 | Technetium | 98 | 98Tc | 97.907 215 | β- | 4.2×106 yr |
44 | Ruthenium | 102 | ![]() |
101.904 348 | 31.6% | |
45 | Rhodium | 103 | ![]() |
102.905 500 | 100% | |
46 | Palladium | 106 | ![]() |
105.903 478 | 27.33% | |
47 | Silver | 107 | ![]() |
106.905 092 | 51.84% | |
109 | ![]() |
108.904 757 | 48.16% | |||
48 | Cadmium | 114 | ![]() |
113.903 357 | 28.73% | |
49 | Indium | 115 | ![]() |
114.903 880 | 95.7%, β- | ![]() |
50 | Tin | 120 | ![]() |
119.902 200 | 32.59% | |
51 | Antimony | 121 | ![]() |
120.903 821 | 57.3% | |
52 | Tellurium | 130 | ![]() |
129.906 229 | 33.8%, β- | ![]() |
53 | Iodine | 127 | ![]() |
126.904 473 | 100% | |
131 | ![]() |
130.906 114 | β- | 8.040 d | ||
54 | Xenon | 132 | ![]() |
131.904 144 | 26.9% | |
136 | ![]() |
135.907 214 | 8.9% | |||
55 | Cesium | 133 | ![]() |
132.905 429 | 100% | |
134 | ![]() |
133.906 696 | EC, β- | 2.06 y | ||
56 | Barium | 137 | ![]() |
136.905 812 | 11.23% | |
138 | ![]() |
137.905 232 | 71.70% | |||
57 | Lanthanum | 139 | ![]() |
138.906 346 | 99.91% | |
58 | Cerium | 140 | ![]() |
139.905 433 | 88.48% | |
59 | Praseodymium | 141 | ![]() |
140.907 647 | 100% | |
60 | Neodymium | 142 | ![]() |
141.907 719 | 27.13% | |
61 | Promethium | 145 | ![]() |
144.912 743 | EC, α | 17.7 y |
62 | Samarium | 152 | ![]() |
151.919 729 | 26.7% | |
63 | Europium | 153 | ![]() |
152.921 225 | 52.2% | |
64 | Gadolinium | 158 | ![]() |
157.924 099 | 24.84% | |
65 | Terbium | 159 | ![]() |
158.925 342 | 100% | |
66 | Dysprosium | 164 | ![]() |
163.929 171 | 28.2% | |
67 | Holmium | 165 | ![]() |
164.930 319 | 100% | |
68 | Erbium | 166 | ![]() |
165.930 290 | 33.6% | |
69 | Thulium | 169 | ![]() |
168.934 212 | 100% | |
70 | Ytterbium | 174 | ![]() |
173.938 859 | 31.8% | |
71 | Lutecium | 175 | ![]() |
174.940 770 | 97.41% | |
72 | Hafnium | 180 | ![]() |
179.946 545 | 35.10% | |
73 | Tantalum | 181 | ![]() |
180.947 992 | 99.98% | |
74 | Tungsten | 184 | ![]() |
183.950 928 | 30.67% | |
75 | Rhenium | 187 | ![]() |
186.955 744 | 62.6%, β- | ![]() |
76 | Osmium | 191 | ![]() |
190.960 920 | β- | 15.4 d |
192 | ![]() |
191.961 467 | 41.0% | |||
77 | Iridium | 191 | ![]() |
190.960 584 | 37.3% | |
193 | ![]() |
192.962 917 | 62.7% | |||
78 | Platinum | 195 | ![]() |
194.964 766 | 33.8% | |
79 | Gold | 197 | ![]() |
196.966 543 | 100% | |
198 | ![]() |
197.968 217 | β- | 2.696 d | ||
80 | Mercury | 199 | ![]() |
198.968 253 | 16.87% | |
202 | ![]() |
201.970 617 | 29.86% | |||
81 | Thallium | 205 | ![]() |
204.974 401 | 70.48% | |
82 | Lead | 206 | ![]() |
205.974 440 | 24.1% | |
207 | ![]() |
206.975 872 | 22.1% | |||
208 | ![]() |
207.976 627 | 52.4% | |||
210 | ![]() |
209.984 163 | α, β- | 22.3 y | ||
211 | ![]() |
210.988 735 | β- | 36.1 min | ||
212 | ![]() |
211.991 871 | β- | 10.64 h | ||
83 | Bismuth | 209 | ![]() |
208.980 374 | 100% | |
211 | ![]() |
210.987 255 | α, β- | 2.14 min | ||
84 | Polonium | 210 | ![]() |
209.982 848 | α | 138.38 d |
85 | Astatine | 218 | ![]() |
218.008 684 | α, β- | 1.6 s |
86 | Radon | 222 | ![]() |
222.017 570 | α | 3.82 d |
87 | Francium | 223 | ![]() |
223.019 733 | α, β- | 21.8 min |
88 | Radium | 226 | ![]() |
226.025 402 | α | ![]() |
89 | Actinium | 227 | ![]() |
227.027 750 | α, β- | 21.8 y |
90 | Thorium | 228 | ![]() |
228.028 715 | α | 1.91 y |
232 | ![]() |
232.038 054 | 100%, α | ![]() |
||
91 | Protactinium | 231 | ![]() |
231.035 880 | α | ![]() |
92 | Uranium | 233 | ![]() |
233.039 628 | α | ![]() |
235 | ![]() |
235.043 924 | 0.720%, α | ![]() |
||
236 | ![]() |
236.045 562 | α | ![]() |
||
238 | ![]() |
238.050 784 | 99.2745%, α | ![]() |
||
239 | ![]() |
239.054 289 | β- | 23.5 min | ||
93 | Neptunium | 239 | ![]() |
239.052 933 | β- | 2.355 d |
94 | Plutonium | 239 | ![]() |
239.052 157 | α | ![]() |
95 | Americium | 243 | ![]() |
243.061 375 | α, fission | ![]() |
96 | Curium | 245 | ![]() |
245.065 483 | α | ![]() |
97 | Berkelium | 247 | ![]() |
247.070 300 | α | ![]() |
98 | Californium | 249 | ![]() |
249.074 844 | α | 351 y |
99 | Einsteinium | 254 | ![]() |
254.088 019 | α, β- | 276 d |
100 | Fermium | 253 | ![]() |
253.085 173 | EC, α | 3.00 d |
101 | Mendelevium | 255 | ![]() |
255.091 081 | EC, α | 27 min |
102 | Nobelium | 255 | ![]() |
255.093 260 | EC, α | 3.1 min |
103 | Lawrencium | 257 | ![]() |
257.099 480 | EC, α | 0.646 s |
104 | Rutherfordium | 261 | ![]() |
261.108 690 | α | 1.08 min |
105 | Dubnium | 262 | ![]() |
262.113 760 | α, fission | 34 s |
106 | Seaborgium | 263 | ![]() |
263.11 86 | α, fission | 0.8 s |
107 | Bohrium | 262 | ![]() |
262.123 1 | α | 0.102 s |
108 | Hassium | 264 | 264Hs | 264.128 5 | α | 0.08 ms |
109 | Meitnerium | 266 | 266Mt | 266.137 8 | α | 3.4 ms |
Table 1: Atomic Masses |