Which of the following statements is not correct regarding diamond and graphite ?

Options

A. In diamond , each carbon atom is covalently bonded to four other carbon atoms
B. In graphite , each carbon atim is covalently bonded to three other carbon atoms in the same plane
C. The C - C bond length is graphite is intermediate between single and double bond distance
D. Diamond is a layered structure , the two layers joined by Van der Waals' forces

Answer

To determine which statement is not correct regarding diamond and graphite, we first need to understand their structures and properties.

### Step-by-Step Solution:

1. **Understanding Diamond Structure**:
- Diamond has a **giant covalent structure** where each carbon atom is **sp³ hybridized**.
- In diamond, each carbon atom forms **four covalent bonds** with four other carbon atoms, creating a **tetrahedral arrangement**.
- This results in a three-dimensional network of carbon atoms, making diamond extremely hard and giving it a high melting point.

2. **Understanding Graphite Structure**:
- Graphite, on the other hand, has a **layered structure** consisting of **hexagonal arrangements** of carbon atoms.
- In graphite, each carbon atom is **sp² hybridized**, forming **three covalent bonds** with three neighboring carbon atoms in the same plane.
- The fourth electron is delocalized, allowing for electrical conductivity within the layers, but the layers themselves are held together by weak van der Waals forces, making them slippery.

3. **Comparing Properties**:
- In diamond, each carbon atom is bonded to **four other carbon atoms**, while in graphite, each carbon atom is bonded to **three other carbon atoms**.
- The C-C bond length in graphite is intermediate between single and double bond distances due to the presence of delocalized electrons.

4. **Identifying the Incorrect Statement**:
- A common misconception is that diamond has a layered structure, which is incorrect. Diamond does not have layers; it has a continuous three-dimensional network.
- Therefore, the statement that claims "diamond is a layered structure" is **not correct**.

### Conclusion:
The statement that is not correct regarding diamond and graphite is that **diamond has a layered structure**.

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