-ium

A systematic element name is the temporary name assigned to a newly synthesized or not yet synthesized chemical element. A systematic symbol is also derived from this name. In chemistry, a transuranic element receives a permanent name and symbol only after its synthesis has been confirmed. In some cases, such as Transfermium Wars, such controversies have been protracted and highly political. In order to discuss such elements without ambiguity, the International Union of Pure and Applied Chemistry (IUPAC) uses a set of rules to assign a temporary systematic name and symbol to each such element. This approach to naming originated in the successful development of regular rules for the naming of organic compounds.

The temporary names are derived systematically from the element's atomic number, and are only applicable for 101 ≤ Z ≤ 999. Each digit is translated to a 'numerical root', according to the table. The roots are concatenated, and the name is completed with the ending suffix . Some of the roots are Latin and others are Greek to avoid two digits starting with the same letter (for example, the Greek-derived pent is used instead of the Latin derived quint to avoid confusion with quad for 4). There are two elision rules designed to prevent odd-looking names.

The suffix -ium overrides traditional chemical suffix rules; thus elements 117 and 118 were ununseptium and ununoctium, not ununseptine and ununocton. This does not apply to the final trivial names these elements receive once confirmed; thus element 117 and 118 are now tennessine and oganesson.

The systematic symbol is formed by taking the first letter of each root, converting the first to a capital. This results in three-letter symbols instead of the one- or two-letter symbols used for named elements.

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