TABLE 655.— INTERNATIONAL ATOMIC WEIGHTS 501 



619 



Element Symbol 



Actinium Ac 



Aluminum Al 



Americium Am 



Antimony Sb 



Argon A 



Arsenic As 



Astatine At 



Barium Ba 



Berkelium Br 



Beryllium Be 



Bismuth Bi 



Boron B 



Bromine Br 



Cadmium Cd 



Calcium Ca 



Californium Cf 



Carbon C 



Cerium Ce 



Cesium Cs 



Chlorine CI 



Chromium Cr 



Cobalt Co 



Copper Cu 



Curium Cm 



Dysprosium Dy 



Erbium Er 



Europium Eu 



Fluorine F 



Francium Fr 



Gadolinium Gd 



Gallium Ga 



Germanium Ge 



Gold Au 



Hafnium Hf 



Helium He 



Holmium Ho 



Hydrogen H 



Indium In 



Iodine I 



Iridium Ir 



Iron Fe 



Krypton Kr 



Lanthanum La 



Lead Pb 



Lithium Li 



Lutetium Lu 



Magnesium Mg 



Manganese Mn 



Mercury Hg 



At Atomic 



Element Symbol No weight * 



Molybdenum Mo 42 95.95 



Neodymium Nd 60 144.27 



Neon Ne 10 20.183 



Neptunium Np 93 [237] 



Nickel Ni 28 58.69 



Niobium Nb 41 92.91 



Nitrogen N 7 14.008 



Osmium Os 76 190.2 



Oxygen O 8 16 



Palladium Pd 46 106.7 



Phosphorus P 15 30.975 



Platinum Pt 78 195.23 



Plutonium Pu 94 [242] 



Polonium Po 84 210 



Potassium K 19 39.100 



Praseodymium . . . Pr 59 140.92 



Promethium Pm 61 [145] 



Protactinium Pa 91 231 



Radium Ra 88 226.05 



Radon Rn 86 222 



Rhenium Re 75 186.31 



Rhodium Rh 45 102.91 



Rubidium Rb 37 85.48 



Ruthenium Ru 44 101.7 



Samarium Sm 62 150.43 



Scandium Sc 21 44.96 



Selenium Se 34 78.96 



Silicon Si 14 28.06 



Silver Ag 47 107.880 



Sodium Na 11 22.997 



Strontium Sr 38 87.63 



Sulfur S 16 32.066 1 



Tantalum Ta 73 180.88 



Technetium Tc 43 [99] 



Tellurium Te 52 127.61 



Terbium Tb 65 1592 



Thallium Tl 81 204.39 



Thorium Th 90 232.12 



Thulium Tm 69 169.4 



Tin Sn 50 118.70 



Titanium Ti 22 47.90 



Tungsten W 74 183.92 



Uranium U 92 238.07 



Vanadium V 23 50.95 



Xenon Xe 54 131.3 



Ytterbium Yb 70 173 04 



Yttrium Y 39 88.92 



Zinc Zn 30 65.38 



Zirconium Zr 40 91.22 



»! Wichcrs, Edward, Journ. Amer. Chem. Soc, vol. 74, p. 2447, 1952. 



* A value given in brackets denotes the mass number of the isotope of longest known half life, 

 t Because of natural variations in the relative abundance of the isotopes of sulfur, the atomic weight of this 

 element has a range of ±.003. 



SMITHSONIAN PHYSICAL TABLES 



