Atomic Masses
[latexpage]
| 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 | \({\beta }^{-}\) | 10.37 min |
| 1 | Hydrogen | 1 | \({\text{}}^{1}\text{H}\) | 1.007 825 | 99.985% | |
| Deuterium | 2 | \({\text{}}^{2}\text{H or D}\) | 2.014 102 | 0.015% | ||
| Tritium | 3 | \({\text{}}^{3}\text{H or T}\) | 3.016 050 | \({\beta }^{-}\) | 12.33 y | |
| 2 | Helium | 3 | \({\text{}}^{3}\text{He}\) | 3.016 030 | \(1\text{.}\text{38}×{\text{10}}^{-4}\text{}\text{%}\) | |
| 4 | \({\text{}}^{4}\text{He}\) | 4.002 603 | \(\text{≈100%}\text{}\) | |||
| 3 | Lithium | 6 | \({\text{}}^{6}\text{Li}\) | 6.015 121 | 7.5% | |
| 7 | \({\text{}}^{7}\text{Li}\) | 7.016 003 | 92.5% | |||
| 4 | Beryllium | 7 | \({\text{}}^{7}\text{Be}\) | 7.016 928 | EC | 53.29 d |
| 9 | \({\text{}}^{9}\text{Be}\) | 9.012 182 | 100% | |||
| 5 | Boron | 10 | \({\text{}}^{10}\text{B}\) | 10.012 937 | 19.9% | |
| 11 | \({\text{}}^{11}\text{B}\) | 11.009 305 | 80.1% | |||
| 6 | Carbon | 11 | \({\text{}}^{11}\text{C}\) | 11.011 432 | EC, \({\beta }^{+}\) | |
| 12 | \({\text{}}^{12}\text{C}\) | 12.000 000 | 98.90% | |||
| 13 | \({\text{}}^{13}\text{C}\) | 13.003 355 | 1.10% | |||
| 14 | \({\text{}}^{14}\text{C}\) | 14.003 241 | \({\beta }^{-}\) | 5730 y | ||
| 7 | Nitrogen | 13 | \({\text{}}^{13}\text{N}\) | 13.005 738 | \({\beta }^{+}\) | 9.96 min |
| 14 | \({\text{}}^{14}\text{N}\) | 14.003 074 | 99.63% | |||
| 15 | \({\text{}}^{15}\text{N}\) | 15.000 108 | 0.37% | |||
| 8 | Oxygen | 15 | \({\text{}}^{15}\text{O}\) | 15.003 065 | EC, \({\beta }^{+}\) | 122 s |
| 16 | \({\text{}}^{16}\text{O}\) | 15.994 915 | 99.76% | |||
| 18 | \({\text{}}^{18}\text{O}\) | 17.999 160 | 0.200% | |||
| 9 | Fluorine | 18 | \({\text{}}^{18}\text{F}\) | 18.000 937 | EC, \({\beta }^{+}\) | 1.83 h |
| 19 | \({\text{}}^{19}\text{F}\) | 18.998 403 | 100% | |||
| 10 | Neon | 20 | \({\text{}}^{20}\text{Ne}\) | 19.992 435 | 90.51% | |
| 22 | \({\text{}}^{22}\text{Ne}\) | 21.991 383 | 9.22% | |||
| 11 | Sodium | 22 | \({\text{}}^{22}\text{Na}\) | 21.994 434 | \({\beta }^{+}\) | 2.602 y |
| 23 | \({\text{}}^{23}\text{Na}\) | 22.989 767 | 100% | |||
| 24 | \({\text{}}^{24}\text{Na}\) | 23.990 961 | \({\beta }^{-}\) | 14.96 h | ||
| 12 | Magnesium | 24 | \({\text{}}^{24}\text{Mg}\) | 23.985 042 | 78.99% | |
| 13 | Aluminum | 27 | \({\text{}}^{27}\text{Al}\) | 26.981 539 | 100% | |
| 14 | Silicon | 28 | \({\text{}}^{28}\text{Si}\) | 27.976 927 | 92.23% | 2.62h |
| 31 | \({\text{}}^{31}\text{Si}\) | 30.975 362 | \({\beta }^{-}\) | |||
| 15 | Phosphorus | 31 | \({\text{}}^{31}\text{P}\) | 30.973 762 | 100% | |
| 32 | \({\text{}}^{32}\text{P}\) | 31.973 907 | \({\beta }^{-}\) | 14.28 d | ||
| 16 | Sulfur | 32 | \({\text{}}^{32}\text{S}\) | 31.972 070 | 95.02% | |
| 35 | \({\text{}}^{35}\text{S}\) | 34.969 031 | \({\beta }^{-}\) | 87.4 d | ||
| 17 | Chlorine | 35 | \({\text{}}^{35}\text{Cl}\) | 34.968 852 | 75.77% | |
| 37 | \({\text{}}^{37}\text{Cl}\) | 36.965 903 | 24.23% | |||
| 18 | Argon | 40 | \({\text{}}^{40}\text{Ar}\) | 39.962 384 | 99.60% | |
| 19 | Potassium | 39 | \({\text{}}^{39}\text{K}\) | 38.963 707 | 93.26% | |
| 40 | \({\text{}}^{40}\text{K}\) | 39.963 999 | 0.0117%, EC, \({\beta }^{-}\) | \(1\text{.}\text{28}×{\text{10}}^{9}\text{y}\) | ||
| 20 | Calcium | 40 | \({\text{}}^{40}\text{Ca}\) | 39.962 591 | 96.94% | |
| 21 | Scandium | 45 | \({\text{}}^{45}\text{Sc}\) | 44.955 910 | 100% | |
| 22 | Titanium | 48 | \({\text{}}^{48}\text{Ti}\) | 47.947 947 | 73.8% | |
| 23 | Vanadium | 51 | \({\text{}}^{51}\text{V}\) | 50.943 962 | 99.75% | |
| 24 | Chromium | 52 | \({\text{}}^{52}\text{Cr}\) | 51.940 509 | 83.79% | |
| 25 | Manganese | 55 | \({\text{}}^{55}\text{Mn}\) | 54.938 047 | 100% | |
| 26 | Iron | 56 | \({\text{}}^{56}\text{Fe}\) | 55.934 939 | 91.72% | |
| 27 | Cobalt | 59 | \({\text{}}^{59}\text{Co}\) | 58.933 198 | 100% | |
| 60 | \({\text{}}^{60}\text{Co}\) | 59.933 819 | \({\beta }^{-}\) | 5.271 y | ||
| 28 | Nickel | 58 | \({\text{}}^{58}\text{Ni}\) | 57.935 346 | 68.27% | |
| 60 | \({\text{}}^{60}\text{Ni}\) | 59.930 788 | 26.10% | |||
| 29 | Copper | 63 | \({\text{}}^{63}\text{Cu}\) | 62.939 598 | 69.17% | |
| 65 | \({\text{}}^{65}\text{Cu}\) | 64.927 793 | 30.83% | |||
| 30 | Zinc | 64 | \({\text{}}^{64}\text{Zn}\) | 63.929 145 | 48.6% | |
| 66 | \({\text{}}^{66}\text{Zn}\) | 65.926 034 | 27.9% | |||
| 31 | Gallium | 69 | \({\text{}}^{69}\text{Ga}\) | 68.925 580 | 60.1% | |
| 32 | Germanium | 72 | \({\text{}}^{72}\text{Ge}\) | 71.922 079 | 27.4% | |
| 74 | \({\text{}}^{74}\text{Ge}\) | 73.921 177 | 36.5% | |||
| 33 | Arsenic | 75 | \({\text{}}^{75}\text{As}\) | 74.921 594 | 100% | |
| 34 | Selenium | 80 | \({\text{}}^{80}\text{Se}\) | 79.916 520 | 49.7% | |
| 35 | Bromine | 79 | \({\text{}}^{79}\text{Br}\) | 78.918 336 | 50.69% | |
| 36 | Krypton | 84 | \({\text{}}^{84}\text{Kr}\) | 83.911 507 | 57.0% | |
| 37 | Rubidium | 85 | \({\text{}}^{85}\text{Rb}\) | 84.911 794 | 72.17% | |
| 38 | Strontium | 86 | \({\text{}}^{86}\text{Sr}\) | 85.909 267 | 9.86% | |
| 88 | \({\text{}}^{88}\text{Sr}\) | 87.905 619 | 82.58% | |||
| 90 | \({\text{}}^{90}\text{Sr}\) | 89.907 738 | \({\beta }^{-}\) | 28.8 y | ||
| 39 | Yttrium | 89 | \({\text{}}^{89}\text{Y}\) | 88.905 849 | 100% | |
| 90 | \({\text{}}^{90}\text{Y}\) | 89.907 152 | \({\beta }^{-}\) | 64.1 h | ||
| 40 | Zirconium | 90 | \({\text{}}^{90}\text{Zr}\) | 89.904 703 | 51.45% | |
| 41 | Niobium | 93 | \({\text{}}^{93}\text{Nb}\) | 92.906 377 | 100% | |
| 42 | Molybdenum | 98 | \({\text{}}^{98}\text{Mo}\) | 97.905 406 | 24.13% | |
| 43 | Technetium | 98 | \({\text{}}^{98}\text{Tc}\) | 97.907 215 | \({\beta }^{-}\) | \(4\text{.}2×{\text{10}}^{6}\text{y}\) |
| 44 | Ruthenium | 102 | \({\text{}}^{102}\text{Ru}\) | 101.904 348 | 31.6% | |
| 45 | Rhodium | 103 | \({\text{}}^{103}\text{Rh}\) | 102.905 500 | 100% | |
| 46 | Palladium | 106 | \({\text{}}^{106}\text{Pd}\) | 105.903 478 | 27.33% | |
| 47 | Silver | 107 | \({\text{}}^{107}\text{Ag}\) | 106.905 092 | 51.84% | |
| 109 | \({\text{}}^{109}\text{Ag}\) | 108.904 757 | 48.16% | |||
| 48 | Cadmium | 114 | \({\text{}}^{114}\text{Cd}\) | 113.903 357 | 28.73% | |
| 49 | Indium | 115 | \({\text{}}^{115}\text{In}\) | 114.903 880 | 95.7%, \({\beta }^{-}\) | \(4\text{.}4×{\text{10}}^{\text{14}}\text{y}\) |
| 50 | Tin | 120 | \({\text{}}^{120}\text{Sn}\) | 119.902 200 | 32.59% | |
| 51 | Antimony | 121 | \({\text{}}^{121}\text{Sb}\) | 120.903 821 | 57.3% | |
| 52 | Tellurium | 130 | \({\text{}}^{130}\text{Te}\) | 129.906 229 | 33.8%, \({\beta }^{-}\) | \(2\text{.}5×{\text{10}}^{\text{21}}\text{y}\) |
| 53 | Iodine | 127 | \({\text{}}^{127}\text{I}\) | 126.904 473 | 100% | |
| 131 | \({\text{}}^{131}\text{I}\) | 130.906 114 | \({\beta }^{-}\) | 8.040 d | ||
| 54 | Xenon | 132 | \({\text{}}^{132}\text{Xe}\) | 131.904 144 | 26.9% | |
| 136 | \({\text{}}^{136}\text{Xe}\) | 135.907 214 | 8.9% | |||
| 55 | Cesium | 133 | \({\text{}}^{133}\text{Cs}\) | 132.905 429 | 100% | |
| 134 | \({\text{}}^{134}\text{Cs}\) | 133.906 696 | EC, \({\beta }^{-}\) | 2.06 y | ||
| 56 | Barium | 137 | \({\text{}}^{137}\text{Ba}\) | 136.905 812 | 11.23% | |
| 138 | \({\text{}}^{138}\text{Ba}\) | 137.905 232 | 71.70% | |||
| 57 | Lanthanum | 139 | \({\text{}}^{139}\text{La}\) | 138.906 346 | 99.91% | |
| 58 | Cerium | 140 | \({\text{}}^{140}\text{Ce}\) | 139.905 433 | 88.48% | |
| 59 | Praseodymium | 141 | \({\text{}}^{141}\text{Pr}\) | 140.907 647 | 100% | |
| 60 | Neodymium | 142 | \({\text{}}^{142}\text{Nd}\) | 141.907 719 | 27.13% | |
| 61 | Promethium | 145 | \({\text{}}^{145}\text{Pm}\) | 144.912 743 | EC, \(\alpha \) | 17.7 y |
| 62 | Samarium | 152 | \({\text{}}^{152}\text{Sm}\) | 151.919 729 | 26.7% | |
| 63 | Europium | 153 | \({\text{}}^{153}\text{Eu}\) | 152.921 225 | 52.2% | |
| 64 | Gadolinium | 158 | \({\text{}}^{158}\text{Gd}\) | 157.924 099 | 24.84% | |
| 65 | Terbium | 159 | \({\text{}}^{159}\text{Tb}\) | 158.925 342 | 100% | |
| 66 | Dysprosium | 164 | \({\text{}}^{164}\text{Dy}\) | 163.929 171 | 28.2% | |
| 67 | Holmium | 165 | \({\text{}}^{165}\text{Ho}\) | 164.930 319 | 100% | |
| 68 | Erbium | 166 | \({\text{}}^{166}\text{Er}\) | 165.930 290 | 33.6% | |
| 69 | Thulium | 169 | \({\text{}}^{169}\text{Tm}\) | 168.934 212 | 100% | |
| 70 | Ytterbium | 174 | \({\text{}}^{174}\text{Yb}\) | 173.938 859 | 31.8% | |
| 71 | Lutecium | 175 | \({\text{}}^{175}\text{Lu}\) | 174.940 770 | 97.41% | |
| 72 | Hafnium | 180 | \({\text{}}^{180}\text{Hf}\) | 179.946 545 | 35.10% | |
| 73 | Tantalum | 181 | \({\text{}}^{181}\text{Ta}\) | 180.947 992 | 99.98% | |
| 74 | Tungsten | 184 | \({\text{}}^{184}\text{W}\) | 183.950 928 | 30.67% | |
| 75 | Rhenium | 187 | \({\text{}}^{187}\text{Re}\) | 186.955 744 | 62.6%, \({\beta }^{-}\) | \(4\text{.}6×{\text{10}}^{\text{10}}\text{y}\) |
| 76 | Osmium | 191 | \({\text{}}^{191}\text{Os}\) | 190.960 920 | \({\beta }^{-}\) | 15.4 d |
| 192 | \({\text{}}^{192}\text{Os}\) | 191.961 467 | 41.0% | |||
| 77 | Iridium | 191 | \({\text{}}^{191}\text{Ir}\) | 190.960 584 | 37.3% | |
| 193 | \({\text{}}^{193}\text{Ir}\) | 192.962 917 | 62.7% | |||
| 78 | Platinum | 195 | \({\text{}}^{195}\text{Pt}\) | 194.964 766 | 33.8% | |
| 79 | Gold | 197 | \({\text{}}^{197}\text{Au}\) | 196.966 543 | 100% | |
| 198 | \({\text{}}^{198}\text{Au}\) | 197.968 217 | \({\beta }^{-}\) | 2.696 d | ||
| 80 | Mercury | 199 | \({\text{}}^{199}\text{Hg}\) | 198.968 253 | 16.87% | |
| 202 | \({\text{}}^{202}\text{Hg}\) | 201.970 617 | 29.86% | |||
| 81 | Thallium | 205 | \({\text{}}^{205}\text{Tl}\) | 204.974 401 | 70.48% | |
| 82 | Lead | 206 | \({\text{}}^{206}\text{Pb}\) | 205.974 440 | 24.1% | |
| 207 | \({\text{}}^{207}\text{Pb}\) | 206.975 872 | 22.1% | |||
| 208 | \({\text{}}^{208}\text{Pb}\) | 207.976 627 | 52.4% | |||
| 210 | \({\text{}}^{210}\text{Pb}\) | 209.984 163 | \(\alpha ,\phantom{\rule{0.20em}{0ex}}{\beta }^{-}\) | 22.3 y | ||
| 211 | \({\text{}}^{211}\text{Pb}\) | 210.988 735 | \({\beta }^{-}\) | 36.1 min | ||
| 212 | \({\text{}}^{212}\text{Pb}\) | 211.991 871 | \({\beta }^{-}\) | 10.64 h | ||
| 83 | Bismuth | 209 | \({\text{}}^{209}\text{Bi}\) | 208.980 374 | 100% | |
| 211 | \({\text{}}^{211}\text{Bi}\) | 210.987 255 | \(\alpha ,\phantom{\rule{0.20em}{0ex}}{\beta }^{-}\) | 2.14 min | ||
| 84 | Polonium | 210 | \({\text{}}^{210}\text{Po}\) | 209.982 848 | \(\alpha \) | 138.38 d |
| 85 | Astatine | 218 | \({\text{}}^{218}\text{At}\) | 218.008 684 | \(\alpha ,\phantom{\rule{0.20em}{0ex}}{\beta }^{-}\) | 1.6 s |
| 86 | Radon | 222 | \({\text{}}^{222}\text{Rn}\) | 222.017 570 | \(\alpha \) | 3.82 d |
| 87 | Francium | 223 | \({\text{}}^{223}\text{Fr}\) | 223.019 733 | \(\alpha ,\phantom{\rule{0.20em}{0ex}}{\beta }^{-}\) | 21.8 min |
| 88 | Radium | 226 | \({\text{}}^{226}\text{Ra}\) | 226.025 402 | \(\alpha \) | \(1\text{.}\text{60}×{\text{10}}^{3}\text{y}\) |
| 89 | Actinium | 227 | \({\text{}}^{227}\text{Ac}\) | 227.027 750 | \(\alpha ,\phantom{\rule{0.20em}{0ex}}{\beta }^{-}\) | 21.8 y |
| 90 | Thorium | 228 | \({\text{}}^{228}\text{Th}\) | 228.028 715 | \(\alpha \) | 1.91 y |
| 232 | \({\text{}}^{232}\text{Th}\) | 232.038 054 | 100%, \(\alpha \) | \(1\text{.}\text{41}×{\text{10}}^{\text{10}}\text{y}\) | ||
| 91 | Protactinium | 231 | \({\text{}}^{231}\text{Pa}\) | 231.035 880 | \(\alpha \) | \(3\text{.}\text{28}×{\text{10}}^{4}\text{y}\) |
| 92 | Uranium | 233 | \({\text{}}^{233}\text{U}\) | 233.039 628 | \(\alpha \) | \(1\text{.}\text{59}×{\text{10}}^{3}\text{y}\) |
| 235 | \({\text{}}^{235}\text{U}\) | 235.043 924 | 0.720%, \(\alpha \) | \(7\text{.}\text{04}×{\text{10}}^{8}\text{y}\) | ||
| 236 | \({\text{}}^{236}\text{U}\) | 236.045 562 | \(\alpha \) | \(2\text{.}\text{34}×{\text{10}}^{7}\text{y}\) | ||
| 238 | \({\text{}}^{238}\text{U}\) | 238.050 784 | 99.2745%, \(\alpha \) | \(4\text{.}\text{47}×{\text{10}}^{9}\text{y}\) | ||
| 239 | \({\text{}}^{239}\text{U}\) | 239.054 289 | \({\beta }^{-}\) | 23.5 min | ||
| 93 | Neptunium | 239 | \({\text{}}^{239}\text{Np}\) | 239.052 933 | \({\beta }^{-}\) | 2.355 d |
| 94 | Plutonium | 239 | \({\text{}}^{239}\text{Pu}\) | 239.052 157 | \(\alpha \) | \(2\text{.}\text{41}×{\text{10}}^{4}\text{y}\) |
| 95 | Americium | 243 | \({\text{}}^{243}\text{Am}\) | 243.061 375 | \(\alpha ,\) fission | \(7\text{.}\text{37}×{\text{10}}^{3}\text{y}\) |
| 96 | Curium | 245 | \({\text{}}^{245}\text{Cm}\) | 245.065 483 | \(\alpha \) | \(8\text{.}\text{50}×{\text{10}}^{3}\text{y}\) |
| 97 | Berkelium | 247 | \({\text{}}^{247}\text{Bk}\) | 247.070 300 | \(\alpha \) | \(1\text{.}\text{38}×{\text{10}}^{3}\text{y}\) |
| 98 | Californium | 249 | \({\text{}}^{249}\text{Cf}\) | 249.074 844 | \(\alpha \) | 351 y |
| 99 | Einsteinium | 254 | \({\text{}}^{254}\text{Es}\) | 254.088 019 | \(\alpha ,\phantom{\rule{0.20em}{0ex}}{\beta }^{-}\) | 276 d |
| 100 | Fermium | 253 | \({\text{}}^{253}\text{Fm}\) | 253.085 173 | EC, \(\alpha \) | 3.00 d |
| 101 | Mendelevium | 255 | \({\text{}}^{255}\text{Md}\) | 255.091 081 | EC, \(\alpha \) | 27 min |
| 102 | Nobelium | 255 | \({\text{}}^{255}\text{No}\) | 255.093 260 | EC, \(\alpha \) | 3.1 min |
| 103 | Lawrencium | 257 | \({\text{}}^{257}\text{Lr}\) | 257.099 480 | EC, \(\alpha \) | 0.646 s |
| 104 | Rutherfordium | 261 | \({\text{}}^{261}\text{Rf}\) | 261.108 690 | \(\alpha \) | 1.08 min |
| 105 | Dubnium | 262 | \({\text{}}^{262}\text{Db}\) | 262.113 760 | \(\alpha ,\) fission | 34 s |
| 106 | Seaborgium | 263 | \({\text{}}^{263}\text{Sg}\) | 263.11 86 | \(\alpha ,\) fission | 0.8 s |
| 107 | Bohrium | 262 | \({\text{}}^{262}\text{Bh}\) | 262.123 1 | \(\alpha \) | 0.102 s |
| 108 | Hassium | 264 | \({\text{}}^{264}\text{Hs}\) | 264.128 5 | \(\alpha \) | 0.08 ms |
| 109 | Meitnerium | 266 | \({\text{}}^{266}\text{Mt}\) | 266.137 8 | \(\alpha \) | 3.4 ms |
