Carbon hexagonal lattice. As of 2009, graphene appears to be the strongest material ever tested. The process of separating it from graphite will require some further technological development before it is economical for industrial processes. If successful, graphene could be used in the construction of a space elevator. It could also be used to safely store hydrogen for use in a hydrogen based engine in cars. The amorphous form is an assortment of carbon atoms in a non-crystalline, irregular, glassy state, not held in a crystalline macrostructure. It is present as a powder, and is the main constituent of substances such
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.