|
Lanthanoids |
Actinoids |
i.
|
In lanthanoids, last differentiating electron occupies 4f orbital. |
In actinoids, last differentiating electron occupies 5f orbital.
|
ii.
|
They are the elements of first inner transition series. |
They are the elements of second inner transition series. |
iii.
|
They are present in period 6. |
They are present in period 7. |
iv.
|
Most of lanthanoids (with exception of promethium) occur in nature.
|
Most of actinoids (with exception of uranium and thorium) are prepared in laboratory. |
v.
|
Most of lanthanoids (with exception of promethium) are non-radioactive. |
All the actinoids are radioactive.
|
vi.
|
Lanthanoids do not form oxo cation.
|
Actinoids form oxo cation such as UO22+ , PuO2+, UO+ . |
vii.
|
4f orbitals in lanthanoids have higher binding energy. |
5f orbitals in actinoids have lower binding energy. |
viii.
|
Contraction in atomic and ionic radii is relatively less in lanthanoids.
|
Contraction in atomic and ionic radii is relatively greater in actinoids due to poor shielding of 5f electrons. |
ix.
|
Lanthanoids shows +2, +3 and +4 oxidation states. |
Actinoids show +3, +4, +5, +6, +7 oxidation states. |
x.
|
Lanthanoids have less tendency to form complexes. |
Actinoids have greater tendency to form complexes. |
xi.
|
Some ions of lanthanoids are coloured.
|
Most of the ions of actinoids are deeply coloured. |
xii.
|
Lanthanoid hydroxides are less basic in nature. |
Actinoid hydroxides are more basic in nature. |