a material is not defined by its atomic ingredients alone. As we now know, the difference between hard transparent diamond and soft black graphite is not to do with their atoms: in both cases, they are made of exactly the same pure element, carbon. It is by changing how they are arranged, by altering them from a cubic structure into layers of hexagonal sheets, that the radical differences in their material properties are brought about. These structures are not arbitrary—you cannot create any structure—but are governed by the rules of quantum mechanics, which treat atoms not as singular
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