Name the products formed when the diamond is burnt in air at 900 C.

Explanation

To determine the products formed when diamond is burnt in air at 900 °C, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Substance**:
- Diamond is an allotrope of carbon. It has a crystalline structure and is known for being one of the hardest substances.

2. **Understand the Reaction Conditions**:
- The question specifies that the burning occurs in air at a temperature of 900 °C. In the presence of oxygen (from the air), carbon can react.

3. **Write the Reaction**:
- When carbon (in the form of diamond) burns in the presence of oxygen, it typically reacts to form carbon dioxide (CO₂). The balanced chemical equation for this reaction is:
\[ C + O_2 \rightarrow CO_2 \]

4. **Identify the Product**:
- At 900 °C, diamond will combust completely in the presence of sufficient oxygen, leading to the formation of carbon dioxide (CO₂).

5. **Conclusion**:
- Therefore, the product formed when diamond is burnt in air at 900 °C is carbon dioxide (CO₂).

### Final Answer:
The product formed when diamond is burnt in air at 900 °C is carbon dioxide (CO₂).

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