The composition of Graphite molecular structure
Graphite is a crystalline mineral of carbonaceous elements, and the crystalline lattice of the Graphite molecular structure is a hexagonal layered structure. The distance between each network layer is 3.40 Å, and the spacing of carbon atoms in the same network layer is 1.42 Å. It is a hexagonal crystal system with complete layered cleavage. The cleavage surface is dominated by molecular bonds, which is weak in attraction to molecules, so its natural buoyancy is very good.
Graphite and diamond, carbon 60, carbon nanotubes, etc. are all simple substances of carbon, and they are allotropes of each other.
The six carbon atoms form a regular six-connected ring on the same plane, extending into a lamellar structure, where the bond length of the CC bond is 142pm, which happens to belong to the bond length range of the atomic crystal, so for the same layer, It is atomic crystal. Carbon atoms in the same plane each have one p orbital left, and they overlap each other. Electrons are relatively free, which is equivalent to free electrons in metals, so graphite can conduct heat and conduct electricity, which is the characteristic of metal crystals. Therefore, it is also classified as a metal crystal.
In the Graphite molecular structure crystal, the layers are separated by 340pm, and the distance is relatively large. They are combined by van der Waals force, that is, the layers belong to molecular crystals. However, due to the strong bonding between carbon atoms on the same plane layer, it is extremely difficult to destroy, so the melting point of graphite is also high, and the chemical properties are also stable.
In view of the special bonding method of the Graphite molecular structure, it cannot be regarded as a single crystal or a polycrystal, and it is generally believed that graphite is a mixed crystal.