Systematic element name

In chemistry, heavy transuranic elements receive a permanent trivial name and symbol only after their synthesis has been confirmed. This has been a protracted and highly political process in some cases (see element naming controversy). In order to discuss newly synthesized and as-yet unsynthesized elements without ambiguity, the IUPAC assigns a temporary systematic name and symbol to such elements. The origin of this idea came from the successful development of regular rules for the naming of organic compounds containing carbon.

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. 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 sandhi 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.

All elements up to and including atomic number 111 have received permanent trivial names and symbols, so the use of systematic names and symbols is recommended only for elements 112 and above. Therefore in practice, systematic names are just those with 3-letter symbols.

Examples

Element 123:
Element 208:
Element 457:
Element 986:>

un + un + enn + ium =   un + bi + tri + ium =   bi + nil + oct + ium =   quad + pent + sept + ium =   enn + oct + hex + ium =

ununennium (Uue)   unbitrium (Ubt)   biniloctium (Bno)   quadpentseptium (Qps)   ennocthexium (Eoh)

:''Note: These examples show conjectured elements. The last theoretically physical possible element is 137, or untriseptium, as elements with a higher atomic number would require the speed of the electrons in their 1s electron orbital to exceed the speed of light. As of 2006, ununhexium, element 116, is the highest confirmed element known.

Trivia

* There is one element whose systematic name is very similar to its permanent trivial name (the symbols are identical). That is element 8: "octium" (O), more commonly known as oxygen (O). If systematic names require three letters, this would be "Nno" (nilniloctium). However, leading zeroes are not written when writing eight (008), so one might also argue against writing leading nils.
* There are 702 possible combinations of letters given single-letter and double-letter naming used in official element names, fewer than the 999 possible names using the triple-letter systematic element naming scheme.

External links

*The IUPAC recommendation. Untitled draft, March 2004. (PDF, 143 kB).
*Systematic naming of Elements with Atomic Numbers Greater than 110 (PDF, 41 kB).