Structures of Carbon Allotropes

Steps:

• Recall diamond's structure: tetrahedral 3D network with each carbon bonded to four others, forming strong covalent bonds.
• Recall graphite's structure: hexagonal layers with each carbon bonded to three others, weak forces between layers, and delocalized electrons within layers.
• Evaluate options: Check each statement against these structures for accuracy on bonding, conductivity, and physical properties.
• Identify correct statement: D matches graphite's layered sliding property.

Why D is correct:

• Graphite's layers are held by weak van der Waals forces, allowing easy sliding like lubricant (intermolecular force definition).

Why the others are wrong:

• A: Opposite; graphite conducts via delocalized electrons, diamond insulates due to localized bonds.
• B: Delocalized electrons exist within layers for conductivity, not between them.
• C: Each diamond carbon bonds to four others in tetrahedral arrangement.

Final answer: D