| # | Symbol | Name | Atomic Mass | Category |
|---|---|---|---|---|
| 58 | Ce | Cerium | 140.116 | Lanthanides |
| 59 | Pr | Praseodymium | 140.908 | Lanthanides |
| 60 | Nd | Neodymium | 144.242 | Lanthanides |
| 61 | Pm | Promethium | 145 | Lanthanides |
| 62 | Sm | Samarium | 150.36 | Lanthanides |
| 63 | Eu | Europium | 151.964 | Lanthanides |
| 64 | Gd | Gadolinium | 157.25 | Lanthanides |
| 65 | Tb | Terbium | 158.925 | Lanthanides |
| 66 | Dy | Dysprosium | 162.5 | Lanthanides |
| 67 | Ho | Holmium | 164.93 | Lanthanides |
| 68 | Er | Erbium | 167.259 | Lanthanides |
| 69 | Tm | Thulium | 168.934 | Lanthanides |
| 70 | Yb | Ytterbium | 173.045 | Lanthanides |
| 71 | Lu | Lutetium | 174.967 | Lanthanides |
| 90 | Th | Thorium | 232.038 | Actinides |
| 91 | Pa | Protactinium | 231.036 | Actinides |
| 92 | U | Uranium | 238.029 | Actinides |
| 93 | Np | Neptunium | 237 | Actinides |
| 94 | Pu | Plutonium | 244 | Actinides |
| 95 | Am | Americium | 243 | Actinides |
| 96 | Cm | Curium | 247 | Actinides |
| 97 | Bk | Berkelium | 247 | Actinides |
| 98 | Cf | Californium | 251 | Actinides |
| 99 | Es | Einsteinium | 252 | Actinides |
| 100 | Fm | Fermium | 257 | Actinides |
| 101 | Md | Mendelevium | 258 | Actinides |
| 102 | No | Nobelium | 259 | Actinides |
| 103 | Lr | Lawrencium | 262 | Actinides |
28 elements