Graphene Graphene Graphene is an allotrope (form) of carbon consisting of a single layer of carbon atoms arranged in a hexagonal lattice. It is a semimetal with small overlap between the valence and the conduction bands (zero bandgap material).<ref name="10.1002/adma.201502544 p.6519-6525"></ref> It is the basic structural element of many other allotropes of carbon, such as graphite, diamond, charcoal, carbon nanotubes and fullerenes. Graphene has many uncommon properties. It is the strongest material ever tested, conducts heat and electricity efficiently, and is nearly transparent. Graphene shows a large and nonlinear diamagnetism, greater than that of graphite, and can be levitated by neodymium
Vector model of the atom considered the extension of the Bohr model because Niels Bohr also proposed angular momentum was quantized according to: where "m" is an integer, produced correct results for the Hydrogen atom. Although the Bohr model doesn't apply to multi-electron atoms, it was the first successful quantization of angular momentum applied to the atom, preceding the vector model of the atom. For one-electron atoms (i.e. hydrogen), there is only one set of cones for the orbiting electron. For multi-electron atoms, there are many states, due to the increasing number of electrons. The angular momenta of all electrons in the atom add vectorially.