Mononuclidic element Complete list of the 22 mononuclidic elements Complete list of the 22 mononuclidic elements

| Element_ | Nuclide | Z_p_ | N_n_ | isotopic_mass_u_ |
|---|---|---|---|---|
| praseodymium | 141 Pr | 59 | 82 | 140.907 65(2) |
| terbium | 159 Tb | 65 | 94 | 158.925 34(2) |
| holmium | 165 Ho | 67 | 98 | 164.930 32(2) |
| thulium | 169 Tm | 69 | 100 | 168.934 21(2) |
| gold | 197 Au | 79 | 118 | 196.966 55(2) |
| bismuth | 209 Bi | 83 | 126 | 208.980 38(2) |
| thorium | 232 Th | 90 | 142 | 232.038 1(1) |
| protactinium | 231 Pa | 91 | 140 | 231.035 88(2) |