Ac 89 (227) Actinium Th 90 232.0381 Thorium Pa 91 231.03588 Protactinium U 92 238.0289 Uranium Es 99 (252) Einsteinium Fm 100 (257) Fermium Md 101 (258) Mendelevium No 102 (259) Nobelium Lr 103 (262) Lawrencium Pu 94 (244) Plutonium Np 93 (237) Neptunium Am 95 (243) Americium Cm 96 (247) Curium Bk 97 (247) Berkelium Cf 98 (251) Californium Actinoids Actinoids La 57 138.9055 Lanthanum Ce 58 140.116 Cerium Pr 59 140.90765 Praseodymium Nd 60 144.24 Neodymium Pm 61 (145) Promethium Sm 62 150.36 Samarium Eu 63 151.964 Europium Gd 64 157.25 Gadolinium Tb 65 158.92534 Terbium Dy 66 162.50 Dysprosium Ho 67 164.93032 Holmium Er 68 167.26 Erbium Tm 69 168.93421 Thulium Yb 70 173.04 Ytterbium Lu 71 174.967 Lutetium Lanthanoids Lanthanoids Hs 108 (265) Hassium Rf 104 (261) Rutherfordium Db 105 (262) Dubnium Bh 107 (264) Bohrium Sg 106 (263) Seaborgium 113 Mt 109 (268) Meitnerium Lv 116 (292) Livermorium Ds 110 (269) Darmstadtium Fl 114 (289) Flerovium Rg 111 (272) Roentgenium Ra 88 226.025 Radium Fr 87 (223) Francium Cn 112 (285) Copernicium Nh (278) Nihonium 115 Mc (288) Moscovium 117 Ts (293) Tennessine 118 Og (293) Oganesson Tl 81 204.3833 Thallium Rn 86 (222) Radon Pb 82 207.2 Lead Bi 83 208.98038 Bismuth Po 84 (209) Polonium At 85 (210) Astatine Au 79 196.96655 Gold Hg 80 200.59 Mercury Ba 56 137.327 Barium Re 75 186.207 Rhenium Os 76 190.23 Osmium Pt 78 195.078 Platinum Ir 77 192.217 Iridium W 74 183.84 Tungsten Ta 73 180.9479 Tantalum Hf 72 178.49 Hafnium Cs 55 132.90545 Cesium In 49 114.818 Indium Xe 54 131.29 Xenon Sn 50 118.710 Tin Sb 51 121.760 Antimony Te 52 127.60 Tellurium I 53 126.90447 Iodine Ag 47 107.8682 Silver Cd 48 112.411 Cadmium Sr 38 87.62 Strontium Tc 43 (98) Technetium Ru 44 101.07 Ruthenium Pd 46 106.42 Palladium Rh 45 102.90550 Rhodium Mo 42 95.94 Molybdenum Nb 41 92.90638 Niobium Zr 40 91.224 Zirconium Y 39 88.90585 Yttrium Rb 37 85.4678 Rubidium Ga 31 69.723 Gallium Kr 36 83.80 Krypton Ge 32 72.61 Germanium As 33 74.92160 Arsenic Se 34 78.96 Selenium Br 35 79.904 Bromine Cu 29 63.546 Copper Zn 30 65.39 Zinc Ca 20 40.078 Calcium Mn 25 54.938049 Manganese Fe 26 55.845 Iron Ni 28 58.6934 Nickel Co 27 58.933200 Cobalt Cr 24 51.9961 Chromium V 23 50.9415 Vanadium Ti 22 47.867 Titanium Sc 21 44.955910 Scandium K 19 39.0983 Potassium Be 4 9.012182 Beryllium Ne 10 20.1797 Neon He 2 4.002602 Helium H 1 1.00794 Hydrogen C 6 12.0107 Carbon N 7 14.00674 Nitrogen O 8 15.9994 Oxygen B 5 10.811 Boron Al 13 26.981538 Aluminum F 9 18.9984032 Fluorine Ar 18 39.948 Argon Si 14 28.0855 Silicon P 15 30.973762 Phosphorus S 16 32.066 Sulfur Cl 17 35.4527 Chlorine Li 3 6.941 Lithium Mg 12 24.3050 Magnesium Na 11 22.989770 Sodium Periodic Table of the Elements 1 2 4 5 6 7 10 11 8 9 12 13 14 15 16 17 18 3 Group numbering is based on the new IUPAC system. Atomic weights are based on C = 12 and conform to the 1995 IUPAC reported values. Number in ( ) indicates the isotope of longest half-life. Illustrated by Masahiko Suenaga http://zzzfelis.sakura.ne.jp 12