1 Hydrogen H 1 1 Gas Non-metal 1.00794 -259.34 -252.87 2 Helium He 18 1 Gas Noble-gas 4.002602 -272.226 -268.934 3 Lithium Li 1 2 Solid Alkali-metal 6.941 180.54 1342 4 Beryllium Be 2 2 Solid Alkaline-earth-metal 9.012182 1278 2970 5 Boron B 13 2 Solid Metalloid 10.811 -7.2 58.78 6 Carbon C 14 2 Solid Non-metal 12.0107 3652 4600 7 Nitrogen N 15 2 Gas Non-metal 14.0067 -209.86 -195.8 8 Oxygen O 16 2 Gas Non-metal 15.9994 -218.4 -182.962 9 Fluorine F 17 2 Gas Halogen 18.9984032 -219.62 -188.4 10 Neon Ne 18 2 Gas Noble-gas 20.1797 -248.67 -246.048 11 Sodium Na 1 3 Solid Alkali-metal 22.98976928 97.81 882.9 12 Magnesium Mg 2 3 Solid Alkaline-earth-metal 24.305 648.8 1090 13 Aluminum Al 13 3 Solid Metal 26.9815386 660.37 2467 14 Silicon Si 14 3 Solid Metalloid 28.0855 1410 2355 15 Phosphorus P 15 3 Solid Non-metal 30.973762 44.1 280 16 Sulfur S 16 3 Solid Non-metal 32.065 112.8 444.674 17 Chlorine Cl 17 3 Gas Halogen 35.453 -100.98 -34.6 18 Argon Ar 18 3 Gas Noble-gas 39.948 -189.2 -185.7 19 Potassium K 1 4 Solid Alkali-metal 39.0983 63.25 759.9 20 Calcium Ca 2 4 Solid Alkaline-earth-metal 40.078 839 1484 21 Scandium Sc 3 4 Solid Transition-metal 44.955912 1541 2836 22 Titanium Ti 4 4 Solid Transition-metal 47.867 1660 32878 23 Vanadium V 5 4 Solid Transition-metal 50.9415 1890 3380 24 Chromium Cr 6 4 Solid Transition-metal 51.9961 1857 2672 25 Manganese Mn 7 4 Solid Transition-metal 54.93845 1244 1962 26 Iron Fe 8 4 Solid Transition-metal 55.845 1535 2750 27 Cobalt Co 9 4 Solid Transition-metal 58.933195 1495 2870 28 Nickel Ni 10 4 Solid Transition-metal 58.6934 1453 2732 29 Copper Cu 11 4 Solid Transition-metal 63.546 1083.4 2567 30 Zinc Zn 12 4 Solid Transition-metal 65.409 419.58 907 31 Gallium Ga 13 4 Solid Metal 69.723 29.78 2403 32 Germanium Ge 14 4 Solid Metalloid 72.64 937.4 2830 33 Arsenic As 15 4 Solid Metalloid 74.9216 817 613 34 Selenium Se 16 4 Solid Non-metal 78.96 217 684.9 35 Bromine Br 17 4 Liquid Halogen 79.904 320.9 765 36 Krypton Kr 18 4 Gas Noble-gas 83.798 -156.6 -152.3 37 Rubidium Rb 1 5 Solid Alkali-metal 85.4678 38.89 686 38 Strontium Sr 2 5 Solid Alkaline-earth-metal 87.62 769 1384 39 Yttrium Y 3 5 Solid Transition-metal 88.90585 1552 5338 40 Zirconium Zr 4 5 Solid Transition-metal 91.224 1852 4377 41 Niobium Nb 5 5 Solid Transition-metal 92.90638 2468 4742 42 Molybdenum Mo 6 5 Solid Transition-metal 95.94 2617 4612 43 Technetium Tc 7 5 Solid Transition-metal -1 2172 4877 44 Ruthenium Ru 8 5 Solid Transition-metal 101.07 2310 3900 45 Rhodium Rh 9 5 Solid Transition-metal 102.9055 1965 3727 46 Palladium Pd 10 5 Solid Transition-metal 106.42 1554 3140 47 Silver Ag 11 5 Solid Transition-metal 107.8682 961.93 2212 48 Cadmium Cd 12 5 Solid Transition-metal 112.411 28.4 669.3 49 Indium In 13 5 Solid Metal 114.818 156.61 2080 50 Tin Sn 14 5 Solid Metal 118.71 231.9681 2270 51 Antimony Sb 15 5 Solid Metalloid 121.76 630.74 1750 52 Tellurium Te 16 5 Solid Metalloid 127.6 449.5 989.8 53 Iodine I 17 5 Solid Halogen 126.90447 113.5 184.35 54 Xenon Xe 18 5 Gas Noble-gas 131.293 -111.9 -107.1 55 Cesium Cs 1 6 Solid Alkali-metal 132.9054519 28.4 669.3 56 Barium Ba 2 6 Solid Alkaline-earth-metal 137.327 725 1640 57 Lanthanum La 3 6 Solid Lanthanide 138.90547 918 3464 58 Cerium Ce 3 6 Solid Lanthanide 140.116 798 3443 59 Praseodymium Pr 3 6 Solid Lanthanide 140.90765 931 3520 60 Neodymium Nd 3 6 Solid Lanthanide 144.242 1021 3074 61 Promethium Pm 3 6 Solid Lanthanide -1 1042 3000 62 Samarium Sm 3 6 Solid Lanthanide 150.36 1074 1794 63 Europium Eu 3 6 Solid Lanthanide 151.964 822 1527 64 Gadolinium Gd 3 6 Solid Lanthanide 157.25 1313 3273 65 Terbium Tb 3 6 Solid Lanthanide 158.92535 1356 3230 66 Dysprosium Dy 3 6 Solid Lanthanide 162.5 1412 2567 67 Holmium Ho 3 6 Solid Lanthanide 164.9332 1474 2700 68 Erbium Er 3 6 Solid Lanthanide 167.259 1529 2868 69 Thulium Tm 3 6 Solid Lanthanide 168.93421 1545 1950 70 Ytterbium Yb 3 6 Solid Lanthanide 173.04 819 1196 71 Lutetium Lu 3 6 Solid Lanthanide 174.967 1663 3402 72 Hafnium Hf 4 6 Solid Transition-metal 178.49 2227 4602 73 Tantalum Ta 5 6 Solid Transition-metal 180.94788 2996 5425 74 Tungsten W 6 6 Solid Transition-metal 183.84 3410 5660 75 Rhenium Re 7 6 Solid Transition-metal 186.207 3180 5627 76 Osmium Os 8 6 Solid Transition-metal 190.23 3045 5027 77 Iridium Ir 9 6 Solid Transition-metal 192.217 2410 4130 78 Platinum Pt 10 6 Solid Transition-metal 195.084 1772 3827 79 Gold Au 11 6 Solid Transition-metal 196.966569 1064.434 2808 80 Mercury Hg 12 6 Liquid Transition-metal 200.59 -38.87 356.58 81 Thallium Tl 13 6 Solid Metal 204.3833 303.5 1457 82 Lead Pb 14 6 Solid Metal 207.2 327.502 1740 83 Bismuth Bi 15 6 Solid Metal 208.984 271.3 1560 84 Polonium Po 16 6 Solid Metalloid -1 254 962 85 Astatine At 17 6 Solid Halogen -1 302 337 86 Radon Rn 18 6 Gas Noble-gas -1 -71 -61.8 87 Francium Fr 1 7 Solid Alkali-metal -1 27 677 88 Radium Ra 2 7 Solid Alkaline-earth-metal -1 700 1140 89 Actinium Ac 3 7 Solid Actinide -1 1050 3200 90 Thorium Th 3 7 Solid Actinide 232.0386 1750 3800 91 Protactinium Pa 3 7 Solid Actinide 231.03588 1600 -1 92 Uranium U 3 7 Solid Actinide 238.02891 1132 3818 93 Neptunium Np 3 7 Solid Actinide 237.048 640 3902 94 Plutonium Pu 3 7 Solid Actinide -1 641 3232 95 Americium Am 3 7 Solid Actinide -1 994 2607 96 Curium Cm 3 7 Solid Actinide -1 1340 -1 97 Berkelium Bk 3 7 Solid Actinide -1 -1 -1 98 Californium Cf 3 7 Solid Actinide -1 -1 -1 99 Einsteinium Es 3 7 Solid Actinide -1 -1 -1 100 Fermium Fm 3 7 Solid Actinide -1 -1 -1 101 Mendelevium Md 3 7 Solid Actinide -1 -1 -1 102 Nobelium No 3 7 Solid Actinide -1 -1 -1 103 Lawrencium Lr 3 7 Solid Actinide -1 -1 -1 ------------------------------------------------------------------------------------------------------------------------------------ (-1) means that the value is unknown References: 1. Pure Appl. Chem., Vol. 78, No. 11, pp. 2051.2066, 2006. ATOMIC WEIGHTS OF THE ELEMENTS 2005, (IUPAC TECHNICAL REPORT) 2. http://en.wikipedia.org/wiki/Chemical_element 3. http://www.csudh.edu/oliver/chemdata/atmass.htm 4. http://environmentalchemistry.com/yogi/periodic/mass.html