Table of the Elements

Table of the elements

The following table gives the atomic mass of the most abundant or most stable isotope for each element, together with a few others. The percentage abundance or decay mode and half life are also listed.

Proton Nucleon Symbol Name Atomic mass Half life % or decay number number (u) mode e Electron 0.000 548 1 1 p Proton 1.007276 1 1 n Neutron 1.008 665 15m  1 1 H Hydrogen 1.007 825 99.985 1 2 D Deuterium 2.014 102 1 3 T Tritium 3.016 049 12.3years  2 3 He Helium 3.016 030 2 4 He Helium 4.002 604 ~100 3 7 Li Lithium 7.016 005 92.58 4 8 Be Beryllium 8.005 308 ~6x10-17 s 2 4 9 Be Beryllium 9.012 186 100 5 11 B Boron 11.009 305 80.4 6 11 C Carbon 11.01143 20.5 mins + 6 12 C Carbon 12.000 000 98.89 6 14 C Carbon 14.003 242 5570 years  7 13 N Nitrogen 13.005739 10.1 min + 7 14 N Nitrogen 14.003 074 99.63 8 15 O Oxygen 15.003 066 122 s + 8 16 O Oxygen 15.994 915 99.76 9 19 F Fluorine 18.998 40 100 10 20 Ne Neon 19.992 440 90.51 10 22 Ne Neon 21.991 384 9.22 11 23 Na Sodium 22.989 773 100 11 24 Na Sodium 23.99097 15 hours - 12 24 Mg Magnesium 23.985 045 78.7 13 27 Al Aluminium 26.981 635 14 28 Si Silicon 27.976 93 15 31 P Phosphorus 30.973 763 100 15 32 P Phosphorus 31.973 908 14.5 days  16 32 S Sulphur 31.927 072 95.0 17 35 Cl Chlorine 34.96885 18 40 Ar Argon 39.962 384 19 39 K Potassium 38.96371 93.26 19 40 K Potassium 39.96401 1.28x109 y  19 41 K Potassium 40.96183 19 42 K Potassium 41.9624 12.5 hours  20 40 Ca Calcium 39.96259 96.97 20 45 Ca Calcium 44.95619 165 days - 20 47 Ca Calcium 46.9545 4.7 days - 21 45 Sc Scandium 44.95592 22 48 Ti Titanium 47.947 95 23 51 V Vanadium 50.94398 24 52 Cr Chromium 5 1.940 51 25 55 Mn Manganese 54.938 88

1 26 54 Fe Iron 53.93962 5.82 26 56 Fe Iron 55.93493 91.66 26 57 Fe Iron 56.935 39 2.19 27 59 Co Cobalt 58.933 19 100 27 60 Co Cobalt 59.93381 5.29 years  28 58 Ni Nickel 57.935 34 29 63 Cu Copper 62.929 59 69.1 30 64 Zn Zinc 63.929 15 48.89 31 69 Ga Gallium 68.925 7 32 74 Ge Germanium 73.9212 36.5 33 75 As Arsenic 74.921 34 80 Se Selenium 79.91651 35 79 Br Bromine 78.918 4 50.54 35 81 Br Bromine 80.9163 49.46 35 85 Br Bromine 84.938 36 84 Kr Krypton 83.91150 37 85 Rb Rubidium 84.911 7 38 88 Sr Strontium 87.905 6 82.6 38 89 Sr Strontium 88.907 51 days  38 90 Sr Strontium 89.9073 28 years  39 89 Y Yttrium 88.905 40 90 Zr Zirconium 89.9043 41 93 Nb Niobium 92.906 0 42 98 Mo Molybdenum 97.906 43 99 Tc Technetium 98.906 * 6 hours  43 101 Tc Technetium 100.9059 44 102 Ru Ruthenium 101.9037 45 103 Rh Rhodium 102.9048 46 106 Pd Palladium 105.9036 47 107 Ag Silver 106.905 51.4 47 111 Ag Silver 110.905 2 7.5 days  48 114 Cd Cadmium 113.9036 49 113 In Indium 112.904 3 49 115 In Indium 114.9041 6x1014 y  50 120 Sn Tin 119.902 51 121 Sb Antimony 120.903 57.25 52 122 Te Tellurium 121.903 53 127 I Iodine 126.90435 100 53 128 I Iodine 127.90583 25 mins  53 131 I Iodine 130.90613 8.04 days  53 132 I Iodine 131.907 997 138 mins  54 129 Xe Xenon 129.90478 26.44 54 132 Xe Xenon 131.90416 26.89 54 133 Xe Xenon 132.9056 5.3 days - 55 133 Cs Caesium 132.905 1 55 137 Cs Caesium 136.9068 28 years  56 138 Ba Barium 137.9050 71.66 56 139 Ba Barium 138.908 6 85 mins  56 140 Ba Barium 139.9105 12.8 days  57 139 La Lanthanum 138.9061 99.91 57 148 La Lanthanum 147.961

2 58 140 Ce Cerium 139.9053 59 141 Pr Praseodymium 140.9074 60 142 Nd Neodymium 141.9075 61 147 Pm Promethium 146.9149 2.6 years  62 152 Sm Samarium 151.919 5 63 151 Eu Europium 150.919 6 64 158 Gd Gadolinium 157.9241 65 159 Tb Terbium 158.9250 66 164 Dy Dysprosium 163.9384 67 165 Ho Holmium 164.9303 68 166 Er Erbium 165.930 4 69 169 Tm Thulium 168.934 70 174 Yb Ytterbium 173.9390 71 175 Lu Lutetium 174.9409 72 180 Hf Hafnium 179.9468 73 181 Ta Tantalum 180.9480 74 184 W Tungsten 183.9510 75 185 Re Rhenium 184.953 76 190 Os Osmium 189.9583 26.4 76 192 Os Osmium 191.9614 41.0 77 193 Ir Iridium 192.9633 78 194 Pt Platinum 193.9628 32.9 78 195 Pt Platinum 194.96482 33.8 79 197 Au Gold 196.96655 100 79 198 Au Gold 197.96824 2.7 days - 80 200 Hg Mercury 199.96834 23.1 80 202 Hg Mercury 201.97063 29.8 80 203 Hg Mercury 202.97285 47 days  81 205 Tl Thallium 204.97446 70.5 82 206 Pb Lead 205.97446 24.1 82 208 Pb Lead 207.97664 52.3 82 209 Pb Lead 208.9810 3.3 hours  83 209 Bi Bismuth 208.98042 100 83 210 Bi Bismuth 209.98411 3x106 y  84 209 Po Polonium 208.98246 200 years  84 210 Po Polonium 209.98287 138 days  85 210 At Astatine 209.987 8.3 hours  86 220 Rn Radon 220.0114 52 s  86 222 Rn Radon 222.017 3.83 days  87 223 Fr Francium 223.0198 22 mins  88 226 Ra Radium 226.02536 1600 years  88 228 Ra Radium 228.03107 1.6x103 y  89 227 Ac Actinium 227.02781 22 years  90 232 Th Thorium 232.03821 1.41x1010 y  91 231 Pa Protoactinium 231.03594 3.4x104 y  91 233 Pa Protoactinium 233.04011 27.4 days  92 235 U Uranium 235.0439 7.1x108 y  92 238 U Uranium 238.0507 4.5x109 y  93 237 Np Neptunium 237.04803 2.2x106 y  94 242 Pu Plutonium 242.0587 3.8x105 y  95 243 Am Americium 243.06138 8x103 y 

3 96 245 Cm Curium 245.06534 104 years  96 248 Cm Curium Fission 5x105 y 97 247 Bk Berkelium 247.07018 104 years  98 249 Cf Californium 249.07570 360 years  99 253 Es Einsteinium 253.08468 20 days  100 250 Fm Fermium 250.07948 30 mins  101 255 Md Mendelevium 255.0906 30 mins  102 255 No Nobelium 255.0933 3.1 mins  103 257 Lw Lawrencium 257.0998 ~35 s 