Scandium  Sc-21 Yttrium  Y-39 Lanthanum  La-57
Cerium  Ce-58 Praseodymium  Pr-59 Neodymium  Nd-60
Promethium  Pm-61 Samarium  Sm-62 Europium  Eu-63
Gadolinium  Gd-64 Terbium  Tb-65 Dysprosium  Dy-66
Holmium  Ho-67 Erbium  Er-68 Thulium  Tm-69
Ytterbium  Yb-70 Lutetium  Lu-71  
Author Compilation (Reference 10)
Table 3: Rare earths.