Disimilarities between Lanthanides and Actinides preparation and properties, Group 18 d – and f – Block Elements

Disimilarities between Lanthanides and Actinides preparation and properties, Group 18 d – and f – Block Elements

Disimilarities between Lanthanides and Actinides :

Despite good many points of similarities between two series there are certainly some points of difference as regards the nature of 4f and 5f orbitals in relation to other neighbourly orbitals. The basic points of difference between actinides and lanthanides have brought out in table 8.17.

Disimilarities between Lanthanides and Actinides preparation and properties, Group 18 d - and f - Block Elements

Table 8.17: Differences between Lanthanides and Actinides

Lanthanoids Actinoids
Except promethirem, they are non-radioactive All actinoides are radio active.
It show very less number of oxidation states. They show only +2 and +4 O.S. in few cases besides +3. They show higher number of oxidation state. They show +4, +5, +6, +7 besides +3.
Lanthanoides show higher shielding effect of 4f electron. Hence it show lesser lanthanoid contraction and show less decrease in ionic radii Actinides show lesser shielding effect of 5f electrons. Hence there is larger decrease in ionic radius.
Bonding energy of 4f electrons are higher. Bonding energy of 5f electrons are comparatively lower.
They do not form oxo ions. They form oxo ions.
The compounds of lanthanoids are less basic. The compounds of actinoids are more basic.
They have less tendency of complex formation. They have greater tendency of complex formation.

Chemistry Notes