Diamond is hard and graphite is soft because of the difference in what?

Diamond is hard and graphite is soft because of the difference in what?

• A. The way their atoms fit together
• B. Their color
• C. Their density
• D. Their chemical composition

Answer: (A)

The difference in how the atoms are arranged and bonded governs hardness. Diamond forms a giant covalent network: each carbon bonds to four neighbors in a strong three-dimensional lattice. That rigid, interconnected structure resists scratching and indentation, making diamond extremely hard. Graphite, on the other hand, has carbon atoms arranged in planar sheets. Within a sheet, bonds are strong, but the sheets are held together by weak forces, so layers can slide past each other and the material is soft by comparison. Colors and densities can vary, but they aren’t what determines hardness. The chemical composition is the same (carbon), so the answer lies in how the atoms are packed and bonded.

The difference in how the atoms are arranged and bonded governs hardness. Diamond forms a giant covalent network: each carbon bonds to four neighbors in a strong three-dimensional lattice. That rigid, interconnected structure resists scratching and indentation, making diamond extremely hard. Graphite, on the other hand, has carbon atoms arranged in planar sheets. Within a sheet, bonds are strong, but the sheets are held together by weak forces, so layers can slide past each other and the material is soft by comparison. Colors and densities can vary, but they aren’t what determines hardness. The chemical composition is the same (carbon), so the answer lies in how the atoms are packed and bonded.