Which material is a one-atom-thick carbon sheet with exceptional electrical properties?

Which material is a one-atom-thick carbon sheet with exceptional electrical properties?

• A. Diamond
• B. Graphite
• C. Graphene
• D. Fullerene

Answer: (C)

A single-atom-thick carbon sheet with exceptional electrical properties is graphene. Graphene is a two-dimensional honeycomb lattice of carbon atoms, where strong in-plane bonds create a robust sheet and the shared outer electrons form a delocalized system that lets electrical charges flow with unusually high mobility across the sheet. This combination—being only one atom thick and highly conductive—gives graphene its standout electrical behavior. Diamond, by contrast, is a three-dimensional network of covalent bonds in which electrons are tightly bound, making it an excellent insulator rather than a good conductor. Graphite consists of many graphene layers stacked together; electrons move well within a layer, but the weak interactions between layers mean the material isn’t a single, highly conductive two-dimensional sheet. Fullerene refers to spherical carbon molecules (buckyballs), not a sheet, and their structure leads to different, less remarkable conductive properties compared to graphene.

A single-atom-thick carbon sheet with exceptional electrical properties is graphene. Graphene is a two-dimensional honeycomb lattice of carbon atoms, where strong in-plane bonds create a robust sheet and the shared outer electrons form a delocalized system that lets electrical charges flow with unusually high mobility across the sheet. This combination—being only one atom thick and highly conductive—gives graphene its standout electrical behavior.

Diamond, by contrast, is a three-dimensional network of covalent bonds in which electrons are tightly bound, making it an excellent insulator rather than a good conductor. Graphite consists of many graphene layers stacked together; electrons move well within a layer, but the weak interactions between layers mean the material isn’t a single, highly conductive two-dimensional sheet. Fullerene refers to spherical carbon molecules (buckyballs), not a sheet, and their structure leads to different, less remarkable conductive properties compared to graphene.