Systematic element name

A systematic element name is the temporary name and symbol assigned to newly synthesized and not yet synthesized chemical elements. In chemistry, a transuranic element receives a permanent name and symbol only after its synthesis has been confirmed. In some cases, this has been a protracted and highly political process (see element naming controversy). 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 IUPAC rules

digit	root	symbol
0	nil	n
1	un	u
2	b(i)	b
3	tr(i)	t
4	quad	q
5	pent	p
6	hex	h
7	sept	s
8	oct	o
9	en(n)	e

The temporary names are derived systematically from the element's atomic number. Each digit is translated to a 'numerical root', according to the table to the right. The roots are concatenated, and the name is completed with the ending -ium. Some of the roots are Latin and others are Greek; the reason is to avoid two digits starting with the same letter. There are two elision rules designed to prevent odd-looking names.

• If bi or tri is followed by the ending ium (i.e. the last digit is 2 or 3), the result is '-bium' or -'trium', not '-biium' or '-triium'.
• If enn is followed by nil (i.e. the sequence -90- occurs), the result is '-ennil-', not '-ennnil-'.

The systematic symbol is formed by taking the first letter of each root, converting the first to a capital.

The suffix -ium overrides traditional chemical suffix rules, thus 117 and 118 are ununseptium and ununoctium, not ununseptine and ununocton.

All elements up to atomic number 112 have received individual permanent names and symbols, so the systematic names and symbols are only used for elements 113 and above. The systematic names are exactly those with 3-letter symbols.

Examples:

Element 122: Element 167: Element 190:

un + bi + bi + um =   un + hex + sept + ium =   un+ en + nil + ium =

unbibium (Ubb)   unhexseptium (Uhs)   unennilium (Uen)

Note: These examples show conjectured elements. As of 2010, Ununoctium, element 118, is the highest-numbered element discovered.

External links

• The IUPAC recommendation. Untitled draft, March 2004. (PDF, 143 kB).
• http://media.iupac.org/publications/pac/2002/pdf/7405x0787.pdf
• American Chemical Society, Committee on Nomenclature, Terminology & Symbols