Van der waals forces in graphite5/22/2023 These electrons are free to move and are responsible for the electrical conductivity of graphite. The fourth electron of each atom is involved in a delocalized p cloud extending between the layers. As the delocalized electrons move around in the sheet, very large temporary dipoles can be set up which will induce opposite dipoles in the sheets above and below - and so on throughout the whole graphite crystal. Only three of the valence electrons of each carbon atom are involved in the covalent bonding of the layers. In graphite you have the ultimate example of van der Waals dispersion forces. These layers are stacked on top of each other in the crystal but the forces between the layers are weak dispersion forces and the layers can slide over each other making graphite soft. Graphite consists of layers of covalently bonded carbon atoms arranged in interlinked hexagonal rings. The atoms are arranged tetrahedrally in the lattice and there are no weak points in the structure, meaning that diamond is very hard.Īll the outer (valence) electrons of the carbon atoms are involved in bonding so there are no electrons free to move through the structure under the influence of an electrical field. In diamond the carbon atoms are arranged in a three-dimensional lattice structure in which all the atoms are linked by single covalent bonds.
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