Which is not a characteristic propery carbon ?

Options

A. It exhibis catenation
B. It forms compounds with multiple bonds.
C. Its melting point and boiling point are exceptionally high.
D. It shows semi-metallic character.

Explanation

To determine which option is not a characteristic property of carbon, we will analyze each given option one by one.

### Step 1: Analyze the Options
1. **Exhibits Catenation**:
- Catenation is the ability of an element to form chains or rings by bonding with itself. Carbon is well-known for its ability to catenate, forming long chains and complex structures.
- **Conclusion**: This is a characteristic property of carbon.

2. **Forms Compounds with Multiple Bonds**:
- Carbon can form various compounds with multiple bonds, such as double bonds (alkenes) and triple bonds (alkynes). This ability is a significant aspect of carbon chemistry.
- **Conclusion**: This is a characteristic property of carbon.

3. **Melting and Boiling Points are Exceptionally High**:
- Carbon has relatively high melting and boiling points compared to other non-metals. For example, diamond (a form of carbon) has a very high melting point.
- **Conclusion**: This is a characteristic property of carbon.

4. **Shows Semi-Metallic Character**:
- Carbon is classified as a non-metal. It does not exhibit semi-metallic (or metalloid) properties. Semi-metals typically have properties of both metals and non-metals, which carbon does not possess.
- **Conclusion**: This is NOT a characteristic property of carbon.

### Final Answer
The option that is not a characteristic property of carbon is **"it shows semi-metallic character."**

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