Question

the structures of two allotropes of carbon are represented above. which of the following statements best helps explain why diamond is much harder than graphite? a diamond contains covalent bonds whereas graphite contains ionic bonds. b diamond contains ionic bonds whereas graphite contains covalent bonds. c carbon atoms in diamond have four covalent bonds, whereas graphite is made of layers that are held together by relatively weak dispersion forces. d carbon atoms in diamond have a sea of mobile electrons that make the structure strong, whereas graphite does not contain delocalized electrons.

Explanation:

Diamond has a three - dimensional covalent network structure where each carbon atom forms four covalent bonds with other carbon atoms. Graphite has a two - dimensional layer structure. The layers in graphite are held together by relatively weak dispersion forces. This difference in structure accounts for the properties such as diamond being hard and graphite being softer.

Answer:

C. Carbon atoms in diamond have four covalent bonds, whereas graphite is made of layers held together by relatively weak dispersion forces.