Atomic numbers and weights.
Element name Abbreviation Atomic number Atomic weight*
Actinium Ac 89 227
Aluminum Al 13 27
Americium** Am 95 243
Antimony Sb 51 121
Argon Ar 18 40
Arsenic As 33 75
Astatine At 85 210
Barium Ba 56 138
Berkelium** Bk 97 247
Beryllium Be 4 9
Bismuth Bi 83 209
Boron B 5 11
Bromine Br 35 79
Cadmium Cd 48 114
Calcium Ca 20 40
Californium** Cf 98 251
Carbon C 6 12
Cerium Ce 58 140
Cesium Cs 55 133
Chlorine Cl 17 35
Chromium Cr 24 52
Cobalt Co 27 59
Copper Cu 29 63
Curium** Cm 96 247
Dysprosium Dy 66 164
Einsteinium** Es 99 254
Erbium Er 68 166
Europium Eu 63 153
Fermium Fm 100 257
Fluorine F 9 19
Francium Fr 87 223
Gadolinium Gd 64 158
Gallium Ga 31 69
Germanium Ge 32 74
Gold Au 79 197
Hafnium Hf 72 180
Helium He 2 4
Holmium Ho 67 165
Hydrogen H 1 1
Indium In 49 115
Iodine I 53 127
Iridium Ir 77 193
Iron Fe 26 56
Krypton Kr 36 84
Lanthanum La 57 139
Lawrencium** Lr or Lw 103 257
