The resistivity (a measure of electrical resistance) of graphite is $(0.4 \text { to } 5.0) \times 10^{-4}\( ohm \)\cdot \mathrm{cm}$ in the basal plane. (The basal plane is the plane of the six-membered rings of carbon atoms.) The resistivity is 0.2 to 1.0 ohm \(\cdot \mathrm{cm}\) along the axis perpendicular to the plane. The resistivity of diamond is \(10^{14}\) to $10^{16} \mathrm{ohm} \cdot \mathrm{cm}$ and is independent of direction. How can you account for this behavior in terms of the structures of graphite and diamond?

Graphite is made up of layers of carbon atoms arranged in a hexagonal lattice. Each carbon atom bonds covalently to three neighboring carbon atoms within the same layer, and there are weak Van der Waals forces between the layers. This structure gives graphite its characteristic properties like good electrical conductivity in the basal plane (the plane of the six-membered rings of carbon atoms) and lower conductivity perpendicular to the plane.

Diamond has a different crystal structure than graphite. In diamond, each carbon atom bonds covalently to four neighboring carbon atoms, forming a three-dimensional tetrahedral lattice. This strong and uniform bonding throughout the crystal results in diamond's properties like high hardness, high thermal conductivity, and very low electrical conductivity.

The directional resistivity of graphite can be understood through its structure. In the basal plane, the carbon atoms share delocalized electrons, which are free to move and conduct electricity. This results in lower resistivity in the basal plane. However, the electrical conductivity perpendicular to the basal plane (along the c-axis) is limited due to the weak Van der Waals forces between the layers and the absence of free electrons for conduction. This is why there is a higher resistivity along the axis perpendicular to the plane.

Diamond's structure makes it a good insulator with high resistivity. Since each carbon atom in diamond forms covalent bonds with four neighbors, there are no free electrons available for conduction. This results in a much higher resistivity in diamond compared to graphite. The structure of diamond is symmetric, so the resistivity is independent of direction. In conclusion, the resistivity behavior in graphite and diamond can be accounted for by understanding their structures. Graphite has directional resistivity due to its layered structure and the presence of free electrons in the basal plane, while diamond has a higher and direction-independent resistivity due to its tetrahedral lattice structure and the absence of free electrons.