Question #44322

Consider the following statements regarding the periodic properties, oxidation states, and acid-base nature of f-block elements and their oxides at $298\text{ K}$:

(I) The basicity of lanthanide(III) oxides ($\ce{Ln2O3}$) decreases smoothly from $\ce{La2O3}$ to $\ce{Lu2O3}$ due to the lanthanide contraction and the resulting increase in the polarizing power of $\ce{Ln^3+}$. (II) The basicity of actinoid(III) oxides ($\ce{An2O3}$) decreases linearly from $\ce{Ac2O3}$ to $\ce{Lr2O3}$, strictly mirroring the electrostatic trend of the actinoid contraction. (III) Late actinoid oxides exhibit a subtle increase in covalent character due to $5f$ orbital hybridization, which disrupts the linear relationship between ionic radius and basicity. (IV) Early actinoids (e.g., $\ce{Th}$, $\ce{U}$, $\ce{Np}$) predominantly form highly stable $+3$ oxides in aqueous media, whereas their higher oxidation state oxides are strongly oxidizing. (V) The $5f$ electrons provide poorer shielding of the nuclear charge than $4f$ electrons, resulting in a more pronounced element-to-element contraction in the actinoid series. (VI) The uranyl ion ($\ce{UO2^2+}$) adopts a linear geometry due to the extensive participation of uranium's $5f$ and $6d$ orbitals in strong covalent bonding with oxygen.

How many of the above statements are CORRECT?