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
Asymmetric carbon atoms are not attached to exactly the same things, there are two different "groups" of atoms that the carbon atom in question is attached to, therefore making it an asymmetric carbon atom: A tetrose with 2 asymmetric carbon atoms has 2 = 4 stereoisomers: An aldopentose with 3 asymmetric carbon atoms has 2 = 8 stereoisomers: An aldohexose with 4 asymmetric carbon atoms has 2 = 16 stereoisomers: The four groups of atoms attached to the carbon atom can be arranged in space in two different ways that are mirror images of each other, and which lead to so-called left-handed