Graphene is a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice structure. It is known for its remarkable electrical, mechanical, and thermal properties. The electrical conductivity of graphene is affected by the number of layers stacked together.1. Single-layer graphene: A single layer of graphene exhibits exceptional electrical conductivity due to its unique electronic structure. The carbon atoms in graphene form a hexagonal lattice, and each carbon atom shares a delocalized electron that is free to move throughout the lattice. This delocalized electron system allows for efficient charge transport, making single-layer graphene an excellent conductor of electricity.2. Bi-layer and few-layer graphene: When two or more layers of graphene are stacked together, the electrical conductivity can be affected by the interlayer interactions and the stacking order. In bi-layer graphene, the electronic properties can be tuned by applying an external electric field, which can modify the band structure and potentially increase or decrease the electrical conductivity. For few-layer graphene typically 3-10 layers , the electrical conductivity can be influenced by factors such as the stacking order, interlayer coupling, and the presence of defects or impurities.3. Multi-layer graphene and graphite: As the number of graphene layers increases, the material eventually transitions into graphite, which has a different electronic structure and lower electrical conductivity compared to single-layer graphene. This is because the interlayer interactions in graphite are dominated by weak van der Waals forces, which reduce the delocalized electron system and hinder efficient charge transport between the layers.In summary, the electrical conductivity of graphene is highly dependent on the number of layers and their interactions. Single-layer graphene exhibits the highest electrical conductivity, while bi-layer and few-layer graphene can have tunable conductivity based on external factors. As the number of layers increases, the electrical conductivity generally decreases due to the reduced delocalized electron system and increased interlayer interactions.