What makes diamonds and graphite different is their:

• A. atomic arrangement
• B. molecular mass
• C. chemical composition
• D. number of protons

Answer: (A)

Verified step by step guidance

1. Understand that both diamond and graphite are allotropes of carbon, meaning they are made of the same element and thus have the same chemical composition and number of protons.
2. Recall that molecular mass depends on the types and numbers of atoms in a molecule; since both diamond and graphite are pure carbon, their molecular masses are effectively the same.
3. Focus on the concept of atomic arrangement, which refers to how atoms are bonded and organized in the solid structure.
4. Recognize that diamond has a three-dimensional tetrahedral network where each carbon atom is bonded to four others, creating a very hard structure.
5. Know that graphite has a layered structure where carbon atoms are bonded in flat sheets with weaker forces between layers, leading to different physical properties compared to diamond.