Which polymorph of carbon act as hadest allotrope ?

Options

A. Diamond
B. Fullerence
C. Graphite
D. All of these

Answer

**Step-by-Step Solution:**

1. **Identify the Allotropes of Carbon:**
Carbon exists in several allotropes, the most common being graphite, diamond, and fullerenes.

2. **Understand the Properties of Each Allotrope:**
- **Graphite:** It has a layered structure, is slippery, and conducts electricity due to the mobility of electrons between layers.
- **Diamond:** It has a tetrahedral structure where each carbon atom is bonded to four other carbon atoms, making it extremely hard.
- **Fullerenes:** These are spherical structures (like buckyballs) made of carbon atoms arranged in a hollow sphere.

3. **Determine Hardness:**
Among these allotropes, diamond is known for its exceptional hardness. It is often used in cutting tools and machining because it can cut through other materials effectively.

4. **Conclusion:**
Therefore, the hardest allotrope of carbon is diamond.

**Final Answer:**
The hardest allotrope of carbon is diamond.

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