The lowest melting point metals among d-block metais belongs to

Options

A. Group 3
B. Group 11
C. Group 6
D. Group 12

Answer

To determine which group of d-block metals has the lowest melting point, we will analyze the groups provided in the question. The d-block elements range from group 3 to group 12 in the periodic table. Let's evaluate each group step by step.

### Step 1: Identify the Groups and Their Elements
- **Group 3**: Scandium (Sc), Yttrium (Y)
- **Group 11**: Copper (Cu), Silver (Ag), Gold (Au)
- **Group 6**: Chromium (Cr), Molybdenum (Mo), Tungsten (W)
- **Group 12**: Zinc (Zn), Cadmium (Cd), Mercury (Hg)

### Step 2: Write the Electronic Configurations
- **Group 3**:
- Sc (21): [Ar] 3d¹ 4s²
- Y (39): [Kr] 4d¹ 5s²
- **Group 11**:
- Cu (29): [Ar] 3d¹⁰ 4s¹
- Ag (47): [Kr] 4d¹⁰ 5s¹
- Au (79): [Xe] 4f¹⁴ 5d¹⁰ 6s¹
- **Group 6**:
- Cr (24): [Ar] 3d⁵ 4s²
- Mo (42): [Kr] 4d⁵ 5s²
- W (74): [Xe] 4f¹⁴ 5d⁴ 6s²
- **Group 12**:
- Zn (30): [Ar] 3d¹⁰ 4s²
- Cd (48): [Kr] 4d¹⁰ 5s²
- Hg (80): [Xe] 4f¹⁴ 5d¹⁰ 6s²

### Step 3: Analyze the Presence of Unpaired Electrons
- **Group 3**: Sc and Y have unpaired electrons.
- **Group 11**: Cu, Ag, and Au have unpaired electrons.
- **Group 6**: Cr, Mo, and W have unpaired electrons.
- **Group 12**: Zn, Cd, and Hg have completely filled d-orbitals (3d¹⁰, 4d¹⁰, 5d¹⁰) and do not have unpaired electrons.

### Step 4: Determine the Melting Points
- Metals with unpaired electrons typically exhibit stronger metallic bonding, leading to higher melting points.
- Group 12 metals (Zn, Cd, Hg) have filled d-orbitals and lack unpaired electrons, which results in weaker metallic bonding and consequently lower melting points.

### Conclusion
Based on the analysis, the group with the lowest melting point among the d-block metals is **Group 12** (Zinc, Cadmium, Mercury). Therefore, the answer is:

**Group 12 (Option D)**

---