Chemical element more than one way, allowing the pure element to exist in multiple chemical structures (spatial arrangements of atoms), known as allotropes, which differ in their properties. For example, carbon can be found as diamond, which has a tetrahedral structure around each carbon atom; graphite, which has layers of carbon atoms with a hexagonal structure stacked on top of each other; graphene, which is a single layer of graphite that is very strong; fullerenes, which have nearly spherical shapes; and carbon nanotubes, which are tubes with a hexagonal structure (even these may differ from each other in electrical properties). The ability
Chemical nomenclature the element name. For example, NH is called "azane". This naming method has been developed principally for coordination compounds although it can be more widely applied. An example of its application is [CoCl(NH)]Cl pentaamminechloridocobalt(III) chloride. Ligands, too, have a special naming convention. Whereas "chloride" becomes the prefix "chloro-" in substitutive naming, in a ligand it becomes "chlorido-". Chemical nomenclature A chemical nomenclature is a set of rules to generate systematic names for chemical compounds. The nomenclature used most frequently worldwide is the one created and developed by the International Union of Pure and Applied Chemistry (IUPAC). The IUPAC's rules for