Atomic Masses of the Elements

Element Symbol At. No. At. Mass M.P., oC B.P., oC
Actinium Ac 89 227.028 1050 3200±300
Aluminum Al 13 26.981539(5) 660.37 2467
Americium Am 95 243 994±4 2607
Antimony Sb 51 121.757 630.74 1750
Argon Ar 18 39.948(1) -189.2 -185.7
Arsenic As 33 74.92159(2) 817 (28 atm) 613(sublimes)
Astatine At 85 210 302 337
Barium Ba 56 137.327(7) 725 1640
Berkelium Bk 97 247
Beryllium Be 4 9.012182(3) 1278±5 2970(5 torr)
Bismuth Bi 83 208.98037(3) 271.3 1560±5
Bohrium Bh 107 262 2079 2550(sublimes)
Boron B 5 10.811(5) -7.2 58.78
Bromine Br 35 79.904 320.9 765
Cadmium Cd 48 112.411(8) 28.40±0.01 669.3
Calcium Ca 20 40.078(9) 839±2 1484
Californium Cf 98 251
Carbon C 6 12.011(1) 3652(sublimes)
Cerium Ce 58 140.115(4) 798 3443
Cesium Cs 55 132.90543(5) 28.40±0.01 669.3
Chlorine Cl 17 35.4527(9) -100.98 -34.6
Chromium Cr 24 51.9961(6) 1857±20 2672
Cobalt Co 27 58.93320(1) 1495 2870
Copper Cu 29 63.546(3) 1083.4±0.2 2567
Curium Cm 96 247 1340±40
Dubnium Db 105 262
Dysprosium Dy 66 162.50(3) 1412 2567
Einsteinium Es 99 252
Erbium Er 68 167.26(3) 1529 2868
Europium Eu 63 151.965(9) 822 1527
Fermium Fm 100 257
Fluorine F 9 18.9984032(9) -219.62 -188.4
Francium Fr 87 223 27 677
Gadolinium Gd 64 157.25(3) 1313 3273
Gallium Ga 31 69.723(1) 29.78 2403
Germanium Ge 32 72.61(2) 937.4 2830
Gold Au 79 196.96654(3) 1064.434 2808±2
Hafnium Hf 72 178.49(2) 2227±20 4602
Hassium Hs 108 265
Helium He 2 4.002602(2) -272.226 amt -268.934
Holmium Ho 67 164.93032(3) 1474 2700
Hydrogen H 1 1.00794(7) -259.34 -252.87
Indium In 49 114.82(1) 156.61 2080
Iodine I 53 126.90447(3) 113.5 184.35
Iridium Ir 77 192.22(3) 2410 4130
Iron Fe 26 55.847(3) 1535 2750
Krypton Kr 36 83.80(1) -156.6 -152.30±0.10
Lanthanum La 57 138.9055(2) 918 3464
Lawrencium Lr 103 262
Lead Pb 82 207.2(1) 327.502 1740
Lithium Li 3 6.941(2) 180.54 1342
Lutetium Lu 71 174.967(1) 1663 3402
Magnesium Mg 12 24.3050(6) 648.8±0.5 1090
Manganese Mn 25 54.93805(1) 1244±3 1962
Meitnerium Mt 109 266
Mendelevium Md 101 258
Mercury Hg 80 200.59(3) -38.87 356.58
Molybdenum Mo 42 95.94(1) 2617 4612
Neodymium Nd 60 144.24(3) 1021 3074
Neon Ne 10 20.1797(6) -248.67 -246.048
Neptunium Np 93 237.048 640±1 3902
Nickel Ni 28 58.6934 1453 2732
Niobium Nb 41 92.90638(2) 2468±10 4742
Nitrogen N 7 14.00674(7) -209.86 -195.8
Nobelium No 102 259
Osmium Os 76 190.2(1) 3045±30 5027±100
Oxygen O 8 15.9994(3) -218.4 -182.962
Palladium Pd 46 106.42(1) 1554 3140
Phosphorus P 15 30.973762(4) 44.1(white) 280(white)
Platinum Pt 78 195.08(3) 1772 3827±100
Plutonium Pu 94 244 641 3232
Polonium Po 84 209 254 962
Potassium K 19 39.0983(1) 63.25 759.9
Praseodymium Pr 59 140.90765(3) 931 3520
Promethium Pm 61 145 1042 3000(estimate)
Protactinium Pa 91 231.0359 1600
Radium Ra 88 226.025 700 1140
Radon Rn 86 222 -71 -61.8
Rhenium Re 75 186.207(1) 3180 5627(estimate)
Rhodium Rh 45 102.90550(3) 1965±3 3727±100
Rubidium Rb 37 85.4678(3) 38.89 686
Ruthenium Ru 44 101.07(2) 2310 3900
Rutherfordium Rf 104 261
Samarium Sm 62 150.36(3) 1074 1794
Scandium Sc 21 44.955910(9) 1541 2836
Seaborgium Sg 106 263
Selenium Se 34 78.96(3) 217 684.9±1.0
Silicon Si 14 28.0855(3) 1410 2355
Silver Ag 47 107.8682(2) 961.93 2212
Sodium Na 11 22.989768(6) 97.81±0.03 882.9
Strontium Sr 38 87.62(1) 769 1384
Sulfur S 16 32.066(6) 112.8 444.674
Tantalum Ta 73 180.9479(1) 2996 5425±100
Technetium Tc 43 98 2172 4877
Tellurium Te 52 127.60(3) 449.5±0.3 989.8±3.8
Terbium Tb 65 158.92534(3) 1356 3230
Thallium Tl 81 204.3833(2) 303.5 1457±10
Thorium Th 90 232.0381(1) 1750 3800(app.)
Thulium Tm 69 168.93421(3) 1545 1950
Tin Sn 50 118.710(7) 231.9681 2270
Titanium Ti 22 47.88(3) 1660±10 32878
Tungsten W 74 183.85(3) 3410±20 5660
Uranium U 92 238.0289(1) 1132±0.8 3818
Vanadium V 23 50.9415(1) 1890±10 3380
Xenon Xe 54 131.29(2) -111.9 -107.1±0.3
Ytterbium Yb 70 173.04(3) 819 1196
Yttrium Y 39 88.90585(2) 1552 5338
Zinc Zn 30 65.39(2) 419.58 907
Zirconium Zr 40 91.224(2) 1852±2 4377