The melting point of copper is higher than that of zinc because

Options

A. the s, p as well as d- electrons of copper are involved in metallic bonding.
B. the atomic volume of copper is higher
C. the d - electrons of copper are involved in metallic bonding
D. the s as well as d- electrons of copper are involved in metallic bonding.

Answer

To understand why the melting point of copper is higher than that of zinc, we need to analyze their electronic configurations and the nature of metallic bonding in both elements.

### Step-by-Step Solution:

1. **Identify the Atomic Numbers and Electronic Configurations**:
- Copper (Cu) has an atomic number of 29. Its electronic configuration is:
\[ \text{Cu: } [Ar] \, 3d^{10} \, 4s^1 \]
- Zinc (Zn) has an atomic number of 30. Its electronic configuration is:
\[ \text{Zn: } [Ar] \, 3d^{10} \, 4s^2 \]

2. **Determine the Stable Oxidation States**:
- The most stable oxidation state of copper in metallic bonding is typically +2 (Cu²⁺), which involves the loss of the 4s electron and one of the 3d electrons.
- Zinc typically forms a +2 oxidation state (Zn²⁺) by losing both of its 4s electrons.

3. **Analyze the Involvement of Electrons in Metallic Bonding**:
- In copper, when forming metallic bonds, the 4s electron and one of the 3d electrons are involved. This means that both s and d electrons contribute to the metallic bonding.
- In zinc, only the 4s electrons are involved in metallic bonding, as the 3d electrons remain fully filled and do not participate in bonding.

4. **Compare the Strength of Metallic Bonds**:
- The presence of d electrons in copper allows for stronger metallic bonding due to the increased number of delocalized electrons. This results in a higher melting point for copper compared to zinc.
- In contrast, zinc's metallic bonding is primarily due to the s electrons, which are less effective in creating strong metallic bonds compared to the d electrons in copper.

5. **Conclusion**:
- Therefore, the melting point of copper is higher than that of zinc because the d electrons of copper are involved in metallic bonding, contributing to stronger interactions between the atoms.

### Final Answer:
The melting point of copper is higher than that of zinc because the d electrons of copper are involved in metallic bonding, leading to stronger metallic bonds compared to zinc, where only s electrons are involved.

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