Lanthanides

Include the following elements elements (preceded by their atomic numbers): 57 lanthanum (La), 58 cerium (Ce), 59 praseodymium (Pr), 60 neodymium (Nd), 61 promethium (Pm), 62 samarium (Sm), 63 europium (Eu), 64 gadolinium (Gd), 65 terbium (Tb), 66 dysprosium (Dy), 67 holmium (Ho), 68 erbium (Er), 69 thulium (Tm), 70 ytterbium (Yb), and 71 lutetium (Lu).

The chemistry of the lanthanides is dominated by the filling of their 4f orbitals.