Naming of chemical elements
Chemical elements may be named from various sources: sometimes based on the person who discovered it, or the place it was discovered. Some have Latin or Greek roots deriving from something related to the element, for example some use to which it may have been put. Known elements. All 118 discovered elements are confirmed and have a formal name and symbol, as decided by IUPAC. The last four names and symbols were added on November 28, 2016. Incidentally, at this moment there are no unconfirmed discoveries and all seven periods (rows) of the periodic table are  completed. Etymology. Element names can refer to: People. Chemical elements are sometimes named after people, especially the synthetic elements discovered (created) after . Very few are named after their discoverers, and only two have been named after living people: the element seaborgium was named after Glenn Seaborg, who was alive at the time of naming in 1997; and in 2016 oganesson was named after Yuri Oganessian (still living ). Many of the transuranic elements are named after recipients of the Nobel Prize: Other transuranic elements are named after scientists who did not receive the prize: The transuranic element flerovium was named after  the Flerov Laboratory of Nuclear Reactions, which in turn was named after Georgy Flyorov. The IUPAC stated that the element was named after the laboratory, not Flyorov, but Yuri Oganessian, who led the team at the laboratory that discovered the element, said that the intention of the naming was to honour Flyorov. The element samarium is named after Vasili Samarsky-Bykhovets, and gadolinium is indirectly named (via the mineral gadolinite) after Johan Gadolin. Lecoq de Boisbaudran, who named the element gallium after his native land of France (from Latin "Gallia" meaning Gaul) denied that the element's naming was for  a pun on his own name ("le coq" means "the rooster" in French, as does "gallus" in Latin). Places on earth. Some chemical elements are named after places on the planet earth. Elements which are named after currently existing countries and cities are as: Several places in Scandinavia have elements named after them. A number of other elements are named after classical words for various places. Astronomical objects. The naming of elements from astronomical objects stems from the ancient association of metals with the various planets and their gods, as follows: mercury with Mercury; copper with Venus; iron with Mars  (named for the Roman god of war); tin with Jupiter (named for the Roman king of the gods); and lead with Saturn (named for the ancient, slow god who was the father of Jupiter). The Sun and the Moon were associated with gold and silver, respectively. A few other elements are directly named for astronomical bodies, including planets, dwarf planets, asteroids, the Earth, the Sun, and the Moon. Uranium, neptunium, plutonium, cerium, and palladium were named after Uranus, Neptune, Pluto, Ceres, and Pallas, respectively. The name selenium comes from the Greek word for the Moon (Σελήνη, "Selene"). Similarly, the name  helium is derived from the Greek word for the Sun (Ἢλιος, "Helios"), as the first evidence for helium came in the form of distinctive emission lines from the Sun that were not explainable by any of the known elements in the 1870s. Tellurium is named after the Latin word "tellus," meaning "earth". Minerals. Many elements are named after the minerals in which they are found, e.g. calcium after Latin "calx" (lime), silicon is named after Latin "silex" (sand), sodium after soda and potassium after potash. Temporary names. In 1979, IUPAC published recommendations for their systematic element names to be used  for yet unnamed or undiscovered elements as a placeholder, until the discovery of the element is confirmed and a permanent name is decided on. The recommendations are mostly ignored among scientists, who simply call these elements by their atomic number, for example "element 119" (instead of "ununennium"), with the symbol of "(119)" or even simply "119". Since 2002, the IUPAC Inorganic Chemistry Division has been the official body responsible with assigning official names to new elements, with the IUPAC Council making the final decision. Chemical symbol. Once an element has been named, a one-, or two-letter symbol must be  ascribed to it so it can be easily referred to in such contexts as the periodic table. The first letter is always capitalised. While the symbol is often a contraction of the element's name, it may sometimes not match the element's name when the symbol is based on non-English words; examples include "Pb" for lead (from "plumbum" in Latin) or "W" for tungsten (from "Wolfram" in German). Elements which have only temporary systematic names are given temporary three-letter symbols (e.g. Uue for ununennium, the undiscovered element 119). Naming controversies. The naming of the synthetic elements dubnium  and seaborgium generated a significant amount of controversy, referred to as the Transfermium Wars. The Americans wished to name element 105 hahnium, while the Russians preferred the name dubnium. The Americans also wished to name element 106 seaborgium. This naming dispute ran from the 1970s (when the elements were discovered) to the 1990s, when the International Union of Pure and Applied Chemistry (IUPAC) created a tentative list of the element names for elements 104 to 109. The Americans, however, refused to agree with these names because seaborgium was not in the list. Thus, IUPAC reconsidered, and in 1996 named element  105 dubnium and element 106 seaborgium. Alternative forms of an element, names indicating molecular structure, and names of compounds. When a pure element, comprising only one type of atom, nevertheless exists in multiple forms (allotropes) with different structure and properties, they are generally given different names; for example graphite and diamond are both forms of the element carbon. Even for elements such as nitrogen having only one stable allotrope, a name such as dinitrogen may be used to indicate its molecular structure N as well as its elemental composition. The naming of chemical compounds comprising more than one element is  a complex subject, discussed at length in the article on chemical nomenclature.