Question

Match the following orders with their properties.

• A. A-I, B-II, C-I, D-IV
• B. A-II, B-I, C-IV, D-III
• C. A-IV, B-III, C-II, D-I
• D. A-III, B-IV, C-II, D-I

Hint:

Transition metal properties depend strongly on number of unpaired d-electrons because stronger metallic bonding increases melting point and atomization enthalpy.

Answer 1

The Correct Option is D

Concept: Transition metals show characteristic periodic trends because of partially filled d-orbitals. Important properties include:

• Enthalpy of atomization

• Density

• Metallic radius

• Melting point
Each property follows trends based on bonding strength and atomic structure.

Step 1: Identify enthalpy of atomization. Strong metallic bonding gives high atomization enthalpy. Order: \[ Fe>Cr>Mn \] Thus \[ A\rightarrow III \]

Step 2: Identify density trend. Density depends on atomic mass and packing. Order: \[ Co>Fe>Mn \] Thus \[ B\rightarrow IV \]

Step 3: Identify metallic radius trend. Across period radius decreases. Order: \[ Ti>V>Cr \] Thus \[ C\rightarrow II \]

Step 4: Identify melting point trend. Melting point depends on bond strength. Order: \[ Cr>V>Mn \] Thus \[ D\rightarrow I \] Final matching: \[ A\rightarrow III \] \[ B\rightarrow IV \] \[ C\rightarrow II \] \[ D\rightarrow I \] Thus answer becomes \[ \boxed{D} \]