IUPAC Periodic Table of the Isotopes
                                                                                                                                                                                                                                                                         Element Background Color Key                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       element name                                                                                                                                                              isotope mass number
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        cadmium 108 (number of protons +
                                                                                                                                                                                                                                                                         Standard atomic weights are the best estimates by IUPAC of atomic weights that are found in normal materials, which are terrestrial                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    106                                     neutrons) 
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        116                                             ,      black indicates
                                                                                                                                                                                                                                                                         materials that are reasonably possible sources for elements and their compounds in commerce, industry, or science. They are                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                element symbol                                                                                                         113 116                                                    .  
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         113                                     114                       isotope is stable
                                                                                                                                                                                                                                                                         determined using all stable isotopes and selected radioactive isotopes (having relatively long half-lives and characteristic terrestrial                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      Cd
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        ,    
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       atomic number                                                                    48                                                                                            . red indicates
                                                                                                                                                                                                                                                                         isotopic compositions). Isotopes are considered stable (non-radioactive) if evidence for radioactive decay has not been detected                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          (number of protons)                                                                                                      110                                                                            isotope is radioactive
                                                                                                                                                                                                                                                                         experimentally.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                isotopic abundance
                                                                                            1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     111                                                                      (mole fraction                                                                                                                                                 18
                                                                                                                                                                                                                                                                                                               Element has two or more isotopes that are used to determine its standard atomic weight. The isotopic abundances and                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             standard                                                                                                              112                                   of isotope)
                                                                  hydrogen                                                                                                                                                                                                                                     atomic weights vary in normal materials. These variations are well known, and the standard atomic weight is given as lower                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  atomic weight                                                                112.414(4)                                                                                                                                                                                                                                   helium
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    {
                                                                 H                                                      2                                                                                                                                                                                      and upper bounds within square brackets, [ ].                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   uncertainty in last digit (112.414 ± 0.004)                                                                                                                                                                                                          He
                                                                  1                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  2                                                      3
                                                                                                                                                                                                                                                                                                               Element has two or more isotopes that are used to determine its standard atomic weight. The isotopic abundances and 
                                                                                       1                                                                                                                                                                                                                       atomic weights vary in normal materials, but upper and lower bounds of the standard atomic weight have not been assigned                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  4
                                                                [1.007 84, 1.008 11]                                                                            2                                                                                                                                              by IUPAC or the variations may be too small to affect the standard atomic weight value significantly. Thus, the standard                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         13                                                                    14                                                                 15                                                                    16                                                                    17                                              4.002 602(2)
                                                                  lithium                                                              beryllium                                                                                                                                                               atomic weight is given as a single value with an uncertainty that includes both measurement uncertainty and uncertainty due                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             boron                                                                 carbon                                                                nitrogen                                                              oxygen                                                                fluorine                                                              neon
                                                                 Li                                                                   Be                                                       9                                                                                                               to isotopic abundance variations.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      B                                                                     C                                                                     N                                                                     O                                                  17                 F                                                     19              Ne 2221
                                                                  3                                                     6              4                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               5                                                     10              6                                                      13             7                                                      15             8                                                      18             9                                                                     10
                                                                                                                                                                                                                                                                                                               Element has only one isotope that is used to determine its standard atomic weight. Thus, the standard atomic weight is 
                                                                                       7                                                                                                                                                                                                                       invariant and is given as a single value with an IUPAC evaluated uncertainty.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              11                                                                   12                                                                    14                                                                     16
                                                                                                                                        9.0121831(5)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   [10.806, 10.821]                                                      [12.0096, 12.0116]                                                  [14.006 43, 14.007 28] [15.999 03, 15.999 77]                                                                                                 18.998403 163(6)                                                                                                         20
                                                                 [6.938, 6.997]                                                                                                                                                                                                                                Element has no standard atomic weight because all of its isotopes are radioactive and, in normal materials, no isotope                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                20.1797(6)
                                                                  sodium                                                               magnesium                                                                                                                                                               occurs with a characteristic isotopic abundance from which a standard atomic weight can be determined.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  aluminium                                                             silicon                                                               phosphorus                                                            sulfur                                                 36             chlorine                                                              argon
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       (aluminum)                                                                                                                                                                                                                                                        33                                                                                                                                         36
                                                                 Na                                                    23             Mg 26                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  27             Si                                                29                  P                                                     31              S                                          34                         Cl                                                                    Ar                                                      38
                                                                  11                                                                   12                                                     25                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      Al                                                                     14                                                    30              15                                                                    16                                                                    17                                                   37               18
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       13                                                                                                                                                                                                                                                                                                           35
                                                                                                                                                              24                                                                         3                                                                     4                                                                     5                                                                    6                                                                     7                                                                     8                                                                    9                                                                  10                                                                    11                                                                    12                                                                                                                                       28                                                                                                                                          32                                                                                                                                            40
                                                                                                                                        [24.304, 24.307]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                26.9815385(7)                                                        [28.084, 28.086]                                                       30.973761 998(5)                                                     [32.059, 32.076]                                                      [35.446, 35.457]
                                                                  22.98976928(2)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     39.948(1)
                                                                                                      
                                                                  potassium                                                            calcium                                             48                scandium                                                              titanium                                                              vanadium                                                              chromium                                                              manganese                                                            iron                                                                  cobalt                                                                nickel                                                                copper                                                                zinc                                                                 gallium                                                               germanium                                                             arsenic                                                               selenium                                                              bromine                                                               krypton
                                                                                                    40                                                                        4442 43                                                                                                                                                                                                                                                                                                                                                                                                                                       57                                                                                                                                       61                                                                                                                                             70                                                                                                                                                                                                                                                                                         74                                                                                                                                78
                                                                                                                                                                                               46                                                                                                                  46 47 49                                                                                                                                           53 50                                                                                                                                          54 58                                                                                                                                     62 64                                                                                                                                         67                                                                                                                                        76                                                                                                                                 82 77                                                                                                                                             80
                                                                 K 41                                                                 Ca                                                                    Sc                                                    45              Ti                                                      50            V                                                     50              Cr                                                    54             Mn 55 Fe                                                                                                                                    Co                                                    59              Ni 60                                                                 Cu                                                     65             Zn68                                                                 Ga                                                     71             Ge70                                                 73               As                                                    75              Se76                                                                  Br                                                    81              Kr 83
                                                                  19                                                                   20                                                                    21                                                                    22                                                                    23                                                                    24                                                                    25                                                                   26                                                                    27                                                                    28                                                                    29                                                                    30                                                                   31                                                                    32                                                                    33                                                                    34                                                                    35                                                                    36 82
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    66                                                                                                                                                                                                                                                                                    78
                                                                                                                                                              40                                                                                                                                         48                                                                    51                                                                    52                                                                                                                                         56                                                                                                                                                                          58                                    63                                                                                                     64                                  69                                                                  72                                 74                                                                                                                                         80                                    79                                                                  86                                  84
                                                                                                                        39
                                                                                                                                       40.078(4)                                                              44.955908(5)                                                         47.867(1)                                                             50.9415(1)                                                           51.9961(6)                                                             54.938044(3)                                                        55.845(2)                                                               58.933194(4)                                                         58.6934(4)                                                             63.546(3)                                                            65.38(2)                                                             69.723(1)                                                             72.630(8)                                                              74.921595(6)                                                         78.971(8)                                                             [79.901, 79.907]
                                                                  39.0983(1)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         83.798(2)
                                                                  rubidium                                                             strontium                                                             yttrium                                                               zirconium                                                             niobium                                                               molybdenum technetium                                                                                                                      ruthenium                                                             rhodium                                                               palladium                                                             silver                                                                cadmium 108 indium                                                                                                                         tin                                                                   antimony                                                              tellurium122123                                                       iodine                                                                xenon                                         124
                                                                                                                                                                                              84                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               102                                                                                                                                         106                                                                                                                                      112114                                                                                                                                  124                                                                                                                                  130 128 126
                                                                                                                                                                         86 87                                                                                    89                                          92                 91                                                                           93                                           97            94                                                                                                                         99 100 96                                                                                      103               Pd 104                                                                                                109                                                             113116                                                                                  113                      Sn 122                                                115                                                     123                           Te                                                     120                                                                127               Xe
                                                                 Rb                                                    87             Sr                                                                    Y                                                                     Zr                                                     96             Nb                                                                    Mo 98 Tc                                                                                                                                   Ru                                                       98           Rh                                                                                                                          106             Ag                                                                    Cd                                                    114            In                                                                                              124                          120            Sb                                                                                                  125                      130            I                                                                                                  136                      132
                                                                  37                                                                   38                                                                    39                                                                    40                                                                    41                                                                    42 100                                                               43                                                                    44                                                                    45                                                                    46 110                                                                47                                                                    48                                                                   49                                                                    50 117                                                                51                                                                    52 126                                                                53                                                                    54 134
                                                                                                                                                                                                                                                                                                    94                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          110
                                                                                                                                                                                                                                                                                                                                                                                                                                                92                                                                                                                                        101                                                                                                                                                                                                                                                                                                                                                                                                                               119
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       105                                                                                                                                          111                                                                                                                                                                                                                                                                                                                                                                                                                              131
                                                                                         85                                                                 88                                                                                                                                                                          90                                                                                                                95                      96                                                                                                                    104                    102                                                                                                                                                                                                        107                                                                  112                                                     115                                                       116                                                                                  121                                                     128
                                                                                                                                        87.62(1)                                                              88.90584(2)                                                          91.224(2)                                                             92.90637(2)                                                           95.95(1)                                                                                                                                   101.07(2)                                                              102.90550(2)                                                         106.42(1)                                        108                  107.8682(2)                                                           112.414(4)                                                           114.818(1)                                                            118.710(7)                                        118                 121.760(1)                                                            127.60(3)                                                             126.90447(3)                                                                                                      129
                                                                  85.4678(3)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         131.293(6)
                                                                  caesium                                                              barium 134                                                                                                                                  hafnium                                                               tantalum                                                              tungsten                                                              rhenium                                                              osmium                                                                iridium                                                               platinum                                                              gold                                                                  mercury                                                              thallium                                                              lead                                                                  bismuth                                                               polonium                                                             astatine                                                              radon
                                                                                                                                                                            135 130                                        57 - 71                                                                                            174                                                                                                                                         180                                                                                                                                      186184                                                                                                                                        192190                                                                                                                                          196
                                                                  (cesium)                                                                                                                 132                                                                                                                          176                                                                                                                                                                                                                                                                                  187                                                                                                                                                                                                                                                                                                                                                                                                                              207
                                                                                                                     133              Ba136                                                                                                                                       Hf179                                                180              Ta                                                  180               W 183 184 Re                                                                                                             185               Os188                                                 192             Ir                                                  191               Pt                                     198                            Au                                                  197               Hg198204 202 Tl                                                                                                         203                Pb                                                204                 Bi                                                  209               Po                                                                   At                                                                    Rn
                                                                                                                                       56 137                                                                      lanthanoids                                                     72                                                                    73                                                                    74                                                                    75                                                                   76                                                                    77                                                                                         196                              195                                                                                   80
                                                                 Cs                                                                                                                                                                                                                                                                                                                                                                           182                                                                                                                                         189                                                                                                                         78                                                                    79                                                                                    201                                                  81                                                                    82                                                                    83                                                                    84                                                                   85                                                                    86
                                                                  55                                                                                                                                                                                                                              177                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      206
                                                                                                                                                                                                                                                                                                                                                                         181                                                                                                                                            187                                                                                                                                       193                                                                                                                                                                                                              199                                                                   205                                                                                                      208
                                                                                                                                                                                          138                                                                                                                         178                                                                                                                                               186                                                                                                                          190                                                                                                                                     194                                                                                                                                                              200
                                                                                                                                        137.327(7)                                                                                                                                 178.49(2)                                                             180.94788(2)                                                          183.84(1)                                                             186.207(1)                                                           190.23(3)                                                             192.217(3)                                                            195.084(9)                                                            196.966569(5)                                                         200.592(3)                                                           [204.382, 204.385]                                                                                                                           208.98040(1)
                                                                  132.905451 96(6)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
                                                                                             
                                                                 francium                                                              radium                                                                           89 - 103                                                   rutherfordium dubnium                                                                                                                       seaborgium                                                           bohrium                                                               hassium                                                               meitnerium                                                            darmstadtium roentgenium                                                                                                                   copernicium                                                           ununtrium                                                             flerovium                                                             ununpentium livermorium                                                                                                                    ununseptium ununoctium
                                                                Fr                                                                    Ra                                                                                                                                          Rf                                                                    Db                                                                   Sg                                                                    Bh                                                                    Hs                                                                    Mt                                                                    Ds                                                                    Rg                                                                   Cn                                                                    Uut                                                                   Fl                                                                    Uup                                                                   Lv                                                                   Uus                                                                   Uuo
                                                                 87                                                                    88                                                                                actinoids                                                 104                                                                   105                                                                   106                                                                  107                                                                   108                                                                   109                                                                   110                                                                   111                                                                  112                                                                   113                                                                   114                                                                   115                                                                   116                                                                  117                                                                   118
                                                                                                                                                                                                                                                                                   lanthanum                                                             cerium                                                                praseodymium                                                          neodymium                                                            promethium                                                            samarium                                                              europium                                                              gadolinium                                                            terbium                                                              dysprosium                                                            holmium                                                               erbium                                                                thulium                                                               ytterbium                                                             lutetium
                                                                                                                                                                                                                                                                                                                                                                                                136138                                                                                                                                                                                                                                                                                  144                                                                                                                                    154152                                                                                                                                         158 156                                                                                                                                 164162                                                                                                                                             168
                                                                                                                                                                                                                                                                                  La                                                                    Ce 142                                                                                                                    141              Nd148150                                                                                                                                    Sm150                                                                 Eu                                                                    Gd                                                                                                                        159              Dy 160                                                                                                                    165               Er                                                                                                                        169               Yb 170                                                                Lu
                                                                                                                                                                                                                                                                                                                                       138                                                                                    Pr                                                                                                                         142             Pm                                                                                          148                             152                                                                   151                                         155                      158              Tb                                                                                            161                          164             Ho                                                                                                 170                     166              Tm                                                                                                176                      174                                                                176
                                                                                                                                                                                                                                                                                   57                                                                    58                                                                    59                                                                    60 145                                                               61                                                                    62                                                                    63                                                                    64                                                                    65                                                                   66                                                                    67                                                                    68                                                                    69                                                                    70                                                                    71
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    143                                                                                                                                                                                                                                                                                    157                                                                                                                                                                                                                                                                                                                                                                                                                                171
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               149                                                                                                                                                                                                                                                                                                                                                                                                                                167
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       163                                                                                                                                                                                                                                                                                                                                                             175
                                                                                                                                                                                                                                                                                                      139                                                                                                                                                                                                                  146                         144                                                                                                               147                        154                                  153                                                                       156                           160                                                                                                                                                                                                                                                                                                                                                                                              173
                                                                                                                                                                                                                                                                                   138.905 47(7)                                                         140.116(1)                                       140                  140.90766(2)                                                          144.242(3)                                                                                                                                 150.36(2)                                                             151.964(1)                                                            157.25(3)                                                             158.92535(2)                                                          162.500(1)                                      162                   164.93033(2)                                                         167.259(3) 168                                                        168.93422(2)                                                          173.054(5)                                  172                       174.9668(1)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
                                                                                                                                                                                                                                                                                   actinium                                                              thorium                                                               protactinium                                                          uranium                                                              neptunium                                                             plutonium                                                             americium                                                             curium                                                               berkelium                                                             californium                                                           einsteinium                                                           fermium                                                               mendelevium nobelium                                                                                                                       lawrencium
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           235 234
                                                                                                                                                                                                                                                                                  Ac                                                                    Th                                                     230            Pa                                                  231              U                                                                     Np                                                                    Pu                                                                    Am                                                                    Cm                                                                   Bk                                                                    Cf                                                                    Es                                                                    Fm                                                                    Md                                                                   No                                                                    Lr
                                                                                                                                                                                                                                                                                   89                                                                    90                                                                    91                                                                    92                                                                   93                                                                    94                                                                    95                                                                    96                                                                   97                                                                    98                                                                    99                                                                    100                                                                   101                                                                  102                                                                   103
                                                                                                                                                                                                                                                                                                                                                                          232
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         238
                                                                                                                                                                                                                                                                                                                                                         232.0377(4)                                                           231.035 88(2)                                                         238.02891(3)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
                                                           International Union of Pure and Applied Chemistry (IUPAC) Project 2007-038-3-200, "Development of an isotopic periodic table for the educational community"                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       October 1, 2013  www.ciaaw.org