Layers of sp2 carbon hexagons with delocalized electrons make it a soft electrical conductor.
Practise Bonding & Molecular Structure All Bonding & Molecular Structure topics
Graphite consists of stacked layers of hexagonal rings of sp2 hybridized carbon atoms. Within each layer the bonds are about 142 pm long, shorter than a typical single bond because of partial double bond character, while the layers are separated by about 335 pm and held together by weak dispersion forces. Each carbon contributes one delocalized pi electron, which moves freely within the layers and gives graphite its electrical conductivity. The layers slide easily over one another, which makes graphite a useful lubricant and gives pencil leads their marking ability. Its anisotropic properties follow directly from this layered structure.
Key ideas: Facts: layer spacing 335 pm, in-layer C-C 142 pm, ABAB stacking, density 2.26 g/cm3. Conductivity is high in the plane and low across it (anisotropy). Lubrication works in air because adsorbed gases or water weaken interlayer attraction, so in vacuum graphite is a poor lubricant. Intercalation of potassium or lithium between layers underlies lithium-ion battery anodes.
Common mistakes and connections: A common mistake is to think weak layers mean weak bonds in graphite overall: in-plane covalent bonding is stronger than in diamond in terms of bond length, and it has a very high melting or sublimation point. Another error is saying graphite is soft because it is covalent. Links to graphene, delocalization and batteries.
Hexagonal sp2 layers with 142 pm C-C bonds are stacked and bound by weak forces, so layers slide easily and delocalized electrons conduct electricity. The interactive lesson shows this as a live animation or chart.
Graphite electrodes are used in electrolysis and in batteries because they conduct electricity well and resist chemical attack.
Layers of sp2 carbon hexagons with delocalized electrons make it a soft electrical conductor.
Graphite Structure is a intermediate topic in Bonding & Molecular Structure. It builds on the vocabulary of beginner topics in this area.
Study these earlier topics in Bonding & Molecular Structure first: Ionic Solids, Metallic Solids, Allotropes of Carbon.
The next topics in Bonding & Molecular Structure are Diamond Structure and Graphene.
Yes. The interactive lesson includes a self-check question on Graphite Structure, and the Bonding & Molecular Structure quiz draws on every topic in this area.
Graphite Structure is topic 84 of 104 in Bonding & Molecular Structure.