The correct answer is option 3: A-III, B-IV-, C-I, D-II.
Let us go through each match in detail:
A. Transition metal can act as a catalyst (Property) - III. Ability to adopt multiple oxidation states and to form complexes (Reason)
Transition metals are known for their ability to adopt multiple oxidation states and to form complexes. These properties make them effective catalysts in various chemical reactions. The variable oxidation states allow them to undergo redox reactions, while the ability to form complexes allows them to interact with reactants and facilitate the reaction process.
B. \(Zr\) and \(Hf\) have similar atomic radii (Property) - IV. As a consequence of the Lanthanide contraction (Reason)
The similar atomic radii of \(Zr\) and \(Hf\) can be attributed to the Lanthanide contraction. As you move across the 4d and 5d transition series, the contraction of atomic radii is observed due to poor shielding of inner electrons by the f-block electrons (lanthanide series). This effect is known as the Lanthanide contraction.
C. Transition metals form complex compounds (Property) - I. Due to their high ionic charges, small size and availability of \(d-\)orbitals (Reason)
Transition metals have high ionic charges and relatively small atomic sizes. Additionally, they have partially filled \(d-\)orbitals, which make them capable of forming complex compounds. The \(d-\)orbitals can accept electron pairs from other ligands, leading to the formation of coordination complexes.
D. Transition metal ions are coloured (Property) - II. Unpaired electrons in \(d\)-orbitals of metal ions (Reason)
The color of transition metal ions is often due to the presence of unpaired electrons in the \(d-\)orbitals. The transition between different energy levels of these electrons corresponds to the absorption of visible light, resulting in colored compounds.
In summary, the matches between properties and reasons are based on the fundamental characteristics of transition metals and their behavior in chemical reactions. |
