Chemical element cubic centimeter (g/cm). Since several elements are gases at commonly encountered temperatures, their densities are usually stated for their gaseous forms; when liquefied or solidified, the gaseous elements have densities similar to those of the other elements. When an element has allotropes with different densities, one representative allotrope is typically selected in summary presentations, while densities for each allotrope can be stated where more detail is provided. For example, the three familiar allotropes of carbon (amorphous carbon, graphite, and diamond) have densities of 1.8–2.1, 2.267, and 3.515 g/cm, respectively. The elements studied to date as solid samples have eight kinds
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