Which statement correctly describes a difference between graphene and graphite? (a) Graphene is a molecule but graphite is not. (b) Graphene is a single sheet of carbon atoms and graphite contains many, and larger, sheets of carbon atoms. (c) Graphene is an insulator but graphite is a metal. (d) Graphite is pure carbon but graphene is not. (e) The carbons are sp2 hybridized in graphene but sp3 hybridized in graphite.

Key Concepts

Structure of Graphene and Graphite

Graphene is a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice, while graphite consists of multiple layers of graphene stacked together. This structural difference leads to distinct physical properties, such as electrical conductivity and mechanical strength, making graphene a highly sought-after material in various applications.

Hybridization of Carbon Atoms

In graphene, each carbon atom is sp2 hybridized, meaning it forms three sigma bonds with neighboring carbon atoms and has one unhybridized p orbital that contributes to delocalized pi bonding. In contrast, graphite's carbon atoms are also primarily sp2 hybridized, allowing for similar bonding characteristics, but the presence of multiple layers affects the overall properties of the material.

Electrical Conductivity

Graphene is an excellent conductor of electricity due to its structure, which allows for the free movement of electrons across its surface. Graphite, while also a good conductor, exhibits different conductivity characteristics because of its layered structure, which can impede electron flow between layers. Understanding these differences is crucial for applications in electronics and materials science.