CBSE Class 12-science Answered

(i) Nature of bonding in La₂O₃ and Lu₂O₃ :

 La₂O₃ is more acidic and Lu₂O₃ is more covalent because as the size decreases covalent character increases.

(ii) Trends in the stability of oxo salts of lanthanoids from La and Lu:

The stability of oxo salts decreases as the size from La to Lu decreases.

(iii) Stability of the complexes of lanthanoids:

Stability of the complexes of lanthanoids increases as the size of lanthanoids decreases.

(iv) Radii of 4d and 5d- block elements :

Radii of 4d and 5d- block elements are almost the same.

(v) Trends in the acidic character of lanthanoid oxides:

From La to Lu the acidic character increases.