Lanthanides are the fourteen elements existing after lanthanum. In these elements, the electrons are progressively filled in the 4f orbitals.
The physical and chemical behaviour of lanthanides can be explained on the basis of their electronic configuration.
Element (Symbol)
|
Atomic Number
|
Electronic Configuration
|
Lanthanum (La)
|
57
|
5d16s2
|
Cerium(Ce)
|
58
|
4f26s2
|
Praseodymium (Pr)
|
59
|
4f36s2
|
Neodymum (Nd)
|
60
|
4f46s2
|
Promethium (Pm)
|
61
|
4f56s2
|
Samarium (Sm)
|
62
|
4f66s2
|
Europium(Eu)
|
63
|
4f76s2
|
Gadolinium(Gd)
|
64
|
4f15d16s2
|
Terbium(Tb)
|
65
|
4f96s2
|
Dysprosium(Dy)
|
66
|
4f106s2
|
Holmium(Ho)
|
67
|
4f116s2
|
Erbium(Er)
|
68
|
4f126s2
|
Thulium(Tm)
|
69
|
4f136s2
|
Ytterbium(Yb)
|
70
|
4f146s2
|
Lutetium(Lu)
|
71
|
4f145d16s2
|
The most characteristic oxidation state of the lanthanides is +3. Some exhibit +2 and +4 oxidation state also.
The lanthanides are dense metals with high melting points. These metals forms alloy easily with other metals, especially with iron.