ABSTRACT
Number Atomic Weight Footnotes Actinium* Ac 89 Aluminum Al 13 26.9815386(8) Americium* Am 95 Antimony Sb 51 121.760(1) g Argon Ar 18 39.948(1) g r Arsenic As 33 74.92160(2) Astatine* At 85 Barium Ba 56 137.327(7) Berkelium* Bk 97 Beryllium Be 4 9.012182(3) Bismuth Bi 83 208.98040(1) Bohrium* Bh 107 Boron B 5 [10.806; 10.821] m Bromine Br 35 79.904(1) Cadmium Cd 48 112.411(8) g Calcium Ca 20 40.078(4) g Californium* Cf 98 Carbon C 6 [12.0096; 12.0116] Cerium Ce 58 140.116(1) g Cesium Cs 55 132.9054519(2) Chlorine Cl 17 [35.446; 35.457] m Chromium Cr 24 51.9961(6) Cobalt Co 27 58.933195(5) Copernicium* Cn 112 Copper Cu 29 63.546(3) r Curium* Cm 96 Darmstadtium* Ds 110 Dubnium* Db 105 Dysprosium Dy 66 162.500(1) g Einsteinium* Es 99 Erbium Er 68 167.259(3) g Europium Eu 63 151.964(1) g Fermium* Fm 100 Fluorine F 9 18.9984032(5)
Element Symbol Atomic
Number Atomic Weight Footnotes Francium* Fr 87 Gadolinium Gd 64 157.25(3) g Gallium Ga 31 69.723(1) Germanium Ge 32 72.63(1) Gold Au 79 196.966569(4) Hafnium Hf 72 178.49(2) Hassium* Hs 108 Helium He 2 4.002602(2) g r Holmium Ho 67 164.93032(2) Hydrogen H 1 [1.00784; 1.00811] m Indium In 49 114.818(3) Iodine I 53 126.90447(3) Iridium Ir 77 192.217(3) Iron Fe 26 55.845(2) Krypton Kr 36 83.798(2) g m Lanthanum La 57 138.90547(7) g Lawrencium* Lr 103 Lead Pb 82 207.2(1) g r Lithium Li 3 [6.938; 6.997] m Lutetium Lu 71 174.9668(1) g Magnesium Mg 12 24.3050(6) Manganese Mn 25 54.938045(5) Meitnerium* Mt 109 Mendelevium* Md 101 Mercury Hg 80 200.59(2) Molybdenum Mo 42 95.96(2) g Neodymium Nd 60 144.242(3) g Neon Ne 10 20.1797(6) g m Neptunium* Np 93 Nickel Ni 28 58.6934(4) r Niobium Nb 41 92.90638(2) Nitrogen N 7 [14.00643; 14.00728] Nobelium* No 102 Osmium Os 76 190.23(3) g
Element Symbol
Number Atomic Weight Footnotes Oxygen O 8 [15.99903; 15.99977] Palladium Pd 46 106.42(1) g Phosphorus P 15 30.973762(2) Platinum Pt 78 195.084(9) Plutonium* Pu 94 Polonium* Po 84 Potassium K 19 39.0983(1) Praseodymium Pr 59 140.90765(2) Promethium* Pm 61 Protactinium** Pa 91 231.03588(2) Radium* Ra 88 Radon* Rn 86 Rhenium Re 75 186.207(1) Rhodium Rh 45 102.90550(2) Roentgenium* Rg 111 Rubidium Rb 37 85.4678(3) g Ruthenium Ru 44 101.07(2) g Rutherfordium* Rf 104 Samarium Sm 62 150.36(2) g Scandium Sc 21 44.955912(6) Seaborgium* Sg 106 Selenium Se 34 78.96(3) r Silicon Si 14 [28.084; 28.086] Silver Ag 47 107.8682(2) g Sodium Na 11 22.98976928(2)
Element Symbol
Number Atomic Weight Footnotes Strontium Sr 38 87.62(1) g r Sulfur S 16 [32.059; 32.076] Tantalum Ta 73 180.94788(2) Technetium* Tc 43 Tellurium Te 52 127.60(3) g Terbium Tb 65 158.92535(2) Thallium Tl 81 [204.382; 204.385] Thorium** Th 90 232.03806(2) g Thulium Tm 69 168.93421(2) Tin Sn 50 118.710(7) g Titanium Ti 22 47.867(1) Tungsten W 74 183.84(1) Ununhexium* Uuh 116 Ununoctium* Uuo 118 Ununpentium* Uup 115 Ununquadium* Uuq 114 Ununseptium Uus 117 Ununtrium* Uut 113 Uranium** U 92 238.02891(3) g m Vanadium V 23 50.9415(1) Xenon Xe 54 131.293(6) g m Ytterbium Yb 70 173.054(5) g Yttrium Y 39 88.90585(2) Zinc Zn 30 65.38(2) r Zirconium Zr 40 91.224(2) g
TABLE 2. CONVENTIONAL ATOMIC WEIGHTS 2009
Element Symbol Atomic
Number Reference Atomic
Weighta Boron B 5 10.81 Carbon C 6 12.011 Chlorine Cl 17 35.45 Hydrogen H 1 1.008 Lithium Li 3 6.94 Nitrogen N 7 14.007 Oxygen O 8 15.999 Silicon Si 14 28.085 Sulfur S 16 32.06 Thallium Tl 81 204.38
