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 | 1.008 665 | 10.37 min | ||
1 | Hydrogen | 1 | 1.007 825 | 99.985% | ||
Deuterium | 2 | 2.014 102 | 0.015% | |||
Tritium | 3 | 3.016 050 | 12.33 y | |||
2 | Helium | 3 | 3.016 030 | |||
4 | 4.002 603 | |||||
3 | Lithium | 6 | 6.015 121 | 7.5% | ||
7 | 7.016 003 | 92.5% | ||||
4 | Beryllium | 7 | 7.016 928 | EC | 53.29 d | |
9 | 9.012 182 | 100% | ||||
5 | Boron | 10 | 10.012 937 | 19.9% | ||
11 | 11.009 305 | 80.1% | ||||
6 | Carbon | 11 | 11.011 432 | EC, | ||
12 | 12.000 000 | 98.90% | ||||
13 | 13.003 355 | 1.10% | ||||
14 | 14.003 241 | 5730 y | ||||
7 | Nitrogen | 13 | 13.005 738 | 9.96 min | ||
14 | 14.003 074 | 99.63% | ||||
15 | 15.000 108 | 0.37% | ||||
8 | Oxygen | 15 | 15.003 065 | EC, | 122 s | |
16 | 15.994 915 | 99.76% | ||||
18 | 17.999 160 | 0.200% | ||||
9 | Fluorine | 18 | 18.000 937 | EC, | 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 | 2.602 y | ||
23 | 22.989 767 | 100% | ||||
24 | 23.990 961 | 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 | |||||
15 | Phosphorus | 31 | 30.973 762 | 100% | ||
32 | 31.973 907 | 14.28 d | ||||
16 | Sulfur | 32 | 31.972 070 | 95.02% | ||
35 | 34.969 031 | 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, | ||||
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 | 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 | 28.8 y | ||||
39 | Yttrium | 89 | 88.905 849 | 100% | ||
90 | 89.907 152 | | 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 | 97.907 215 | | ||
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%, | ||
50 | Tin | 120 | 119.902 200 | 32.59% | ||
51 | Antimony | 121 | 120.903 821 | 57.3% | ||
52 | Tellurium | 130 | 129.906 229 | 33.8%, | ||
53 | Iodine | 127 | 126.904 473 | 100% | ||
131 | 130.906 114 | | 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, | 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, | 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%, | ||
76 | Osmium | 191 | 190.960 920 | | 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 | | 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 | , | 22.3 y | |||
211 | 210.988 735 | 36.1 min | ||||
212 | 211.991 871 | 10.64 h | ||||
83 | Bismuth | 209 | 208.980 374 | 100% | ||
211 | 210.987 255 | , | 2.14 min | |||
84 | Polonium | 210 | 209.982 848 | 138.38 d | ||
85 | Astatine | 218 | 218.008 684 | , | 1.6 s | |
86 | Radon | 222 | 222.017 570 | 3.82 d | ||
87 | Francium | 223 | 223.019 733 | , | 21.8 min | |
88 | Radium | 226 | 226.025 402 | |||
89 | Actinium | 227 | 227.027 750 | , | 21.8 y | |
90 | Thorium | 228 | 228.028 715 | 1.91 y | ||
232 | 232.038 054 | 100%, | ||||
91 | Protactinium | 231 | 231.035 880 | |||
92 | Uranium | 233 | 233.039 628 | |||
235 | 235.043 924 | 0.720%, | ||||
236 | 236.045 562 | |||||
238 | 238.050 784 | 99.2745%, | ||||
239 | 239.054 289 | 23.5 min | ||||
93 | Neptunium | 239 | 239.052 933 | 2.355 d | ||
94 | Plutonium | 239 | 239.052 157 | |||
95 | Americium | 243 | 243.061 375 | , fission | ||
96 | Curium | 245 | 245.065 483 | |||
97 | Berkelium | 247 | 247.070 300 | |||
98 | Californium | 249 | 249.074 844 | 351 y | ||
99 | Einsteinium | 254 | 254.088 019 | , | 276 d | |
100 | Fermium | 253 | 253.085 173 | EC, | 3.00 d | |
101 | Mendelevium | 255 | 255.091 081 | EC, | 27 min | |
102 | Nobelium | 255 | 255.093 260 | EC, | 3.1 min | |
103 | Lawrencium | 257 | 257.099 480 | EC, | 0.646 s | |
104 | Rutherfordium | 261 | 261.108 690 | 1.08 min | ||
105 | Dubnium | 262 | 262.113 760 | , fission | 34 s | |
106 | Seaborgium | 263 | 263.11 86 | , fission | 0.8 s | |
107 | Bohrium | 262 | 262.123 1 | 0.102 s | ||
108 | Hassium | 264 | 264.128 5 | 0.08 ms | ||
109 | Meitnerium | 266 | 266.137 8 | 3.4 ms |