5
4 5
4 5
4 5 The
The
The
The
The
Lanthanoids
Lanthanoids
Lanthanoids
Lanthanoids
Lanthanoids
Rationalised 2023-24
109
The d- and f- Block Elements
La
3+
Ce
3+
Pr
3+
Nd
3+
Pm
3+
Sm
3+
Eu
3+
Gd
3+
Tb
3+
Dy
3+
Ho
3+
Er
3+
Tm
3+
Yb
3+
Lu
3+
Ce
4+
Pr
4+
Tb
4+
Yb
2+
Tm
2+
Sm
2
Eu
2+
110
100
90
57
61
65
59
63
67
69
71
Ionic radii/pm
Atomic number
+
4