How does graphite structure differ from diamond?

Graphite differs from diamond primarily in its bonding and electronic structure, which is why the statement about graphite having delocalised electrons while diamond does not is accurate. In graphite, each carbon atom is bonded to three other carbon atoms in a planar hexagonal arrangement, creating layers of graphene. Within these layers, the fourth outer shell electron of each carbon atom is not bonded but instead becomes delocalised across the layers. This delocalisation allows graphite to conduct electricity and gives it lubricating properties.

On the other hand, diamond has a very different structure. Each carbon atom forms four strong covalent bonds with other carbon atoms in a three-dimensional tetrahedral arrangement. This results in a very rigid and strong structure, and all four outer shell electrons of the carbon atoms are involved in bonding, leaving no delocalised electrons available.

Understanding the nature of these orbital arrangements and the presence or absence of delocalised electrons is crucial in realizing the differences in the properties of these two forms of carbon.