Statement I : Actinides form relatively less stable complexes as compa...
Acitinides form relatively more stable complexes as compared to lanthanides.
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Statement I : Actinides form relatively less stable complexes as compa...
Statement I: Actinides form relatively less stable complexes as compared to lanthanides.
Actinides are a series of elements that include actinium (Ac) and all the elements from thorium (Th) to lawrencium (Lr). Lanthanides are a series of elements that include lanthanum (La) and all the elements from cerium (Ce) to lutetium (Lu).
Actinides have a larger atomic radius and a higher effective nuclear charge compared to lanthanides. This means that actinides have a greater attraction for electrons and are more likely to form stable complexes.
Statement II: Actinides can utilize their 5f-orbitals along with 6d-orbitals in bonding, but lanthanides do not use their 4f-orbitals for bonding.
The electronic configuration of actinides involves the filling of the 5f-orbitals, while lanthanides involve the filling of the 4f-orbitals. The 5f-orbitals are more diffuse and have a higher energy compared to the 4f-orbitals.
Due to the higher energy of the 5f-orbitals, actinides can participate in bonding with other atoms by utilizing both their 5f and 6d-orbitals. This allows actinides to form a greater variety of bonding arrangements and to form stable complexes.
On the other hand, lanthanides do not use their 4f-orbitals for bonding because these orbitals are more tightly held by the nucleus and are not available for bonding. Lanthanides primarily use their 6s, 5d, and 6p orbitals for bonding.
Explanation:
Statement I is correct because actinides do form relatively less stable complexes compared to lanthanides. This is due to the larger atomic radius and higher effective nuclear charge of actinides, which leads to a stronger attraction for electrons and the formation of less stable complexes.
Statement II is correct because actinides can utilize their 5f-orbitals along with 6d-orbitals in bonding, while lanthanides do not use their 4f-orbitals for bonding. The higher energy and greater diffuseness of the 5f-orbitals in actinides allow for a greater variety of bonding arrangements and the formation of stable complexes. Lanthanides, on the other hand, primarily use their 6s, 5d, and 6p orbitals for bonding.
Therefore, the correct answer is option D: Statement II is correct, but Statement I is incorrect.