View source for Systematic element name

{{short description|Temporary name assigned to predicted chemical elements}}
{{sidebar periodic table|history}}
A '''systematic element name''' is the  temporary name assigned to an unknown or recently synthesized [[chemical element]]. A systematic [[Chemical symbol|symbol]] is also derived from this name.

In chemistry, a [[transuranium element|transuranic element]] receives a permanent name and symbol only after its synthesis has been confirmed. In some cases, such as the [[Transfermium Wars]], [[element naming controversy|controversies over the formal name and symbol]] 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, adopted in 1978, to assign a temporary systematic name and symbol to each such element. This approach to naming originated in the successful development of regular [[IUPAC nomenclature of organic chemistry|rules for the naming of organic compounds]].

==IUPAC rules ==
The temporary names derive systematically from the element's [[atomic number]], and apply only to 101&nbsp;≤&nbsp;''Z''&nbsp;≤&nbsp;999.<ref name=qmul>{{Cite web|url=https://www.qmul.ac.uk/sbcs/iupac/AtWt/element.html|title=Element names >100}}</ref> Each digit is translated into a "numerical root" according to the table. The roots are [[concatenation|concatenated]], and the name is completed by the suffix ''[[wikt:-ium#Suffix|-ium]]''. Some of the roots are [[Latin]] and others are [[Greek language|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.

Traditionally the suffix ''-ium'' was used only for metals (or at least elements that were expected to be metallic), and other elements used different suffixes: [[halogen]]s used ''-ine'' and [[noble gas]]es used ''-on'' instead. However, the systematic names use ''-ium'' for all elements regardless of group. Thus, elements 117 and 118 were ''ununseptium'' and ''ununoctium'', not ''ununseptine'' and ''ununocton''.<ref name=Koppenol>{{cite journal |last= Koppenol|first=W.|date= 2016|title=How to name new chemical elements|journal=Pure and Applied Chemistry |publisher=DeGruyter |doi=10.1515/pac-2015-0802|hdl=10045/55935|s2cid=102245448|url=http://rua.ua.es/dspace/bitstream/10045/55935/1/2016_Koppenol_etal_PureApplChem.pdf|hdl-access=free}}</ref> This does not apply to the [[trivial name]]s these elements receive once confirmed; thus, elements 117 and 118 are now ''[[tennessine]]'' and ''[[oganesson]]'', respectively. For these trivial names, all elements receive the suffix ''-ium'' except those in group 17, which receive ''-ine'' (like the halogens), and those in group 18, which receive ''-on'' (like the noble gases).<ref name=Koppenol/> (That being said, tennessine and oganesson are expected to behave quite differently from their lighter congeners.)

The systematic symbol is formed by taking the first letter of each root, converting the first to uppercase. This results in three-letter symbols instead of the one- or two-letter symbols used for named elements. The rationale is that any scheme producing two-letter symbols will have to deviate from full systematicity to avoid collisions with the symbols of the permanently named elements.

The Recommendations for the Naming of Elements of Atomic Numbers Greater than 100 can be found [https://www.degruyter.com/view/journals/pac/51/2/article-p381.xml here].

{| align="left" class="wikitable" style="margin-right: 1.5em; text-align:center; font-size:90%"
!Digit!!Root!!Etymology!!Symbol!!Pronunciation
! Example
|-
|'''0'''||nil||Latin ''nihil'' ("zero")||'''n'''||{{IPAc-en|n|ɪ|l}}
| style="text-align:left;" | unbinilium
|-
|'''1'''||un||Latin ''unus'' ("one")||'''u'''||{{IPAc-en|uː|n}}
| style="text-align:left;" | unbiunium
|-
|'''2'''||bi||Latin ''bis'' ("twice")||'''b'''||{{IPAc-en|b|aɪ}}
| style="text-align:left;" | unbibium
|-
|'''3'''||tri||Latin ''tres'' ("three")<br/>Greek ''tria'' ("three")||'''t'''||{{IPAc-en|t|r|aɪ}}
| style="text-align:left;" | unbitrium
|-
|'''4'''||quad||Latin ''quattuor'' ("four")||'''q'''||{{IPAc-en|k|w|ɒ|d}}
| style="text-align:left;" | unbiquadium
|-
|'''5'''||pent||Greek ''pente'' ("five")||'''p'''||{{IPAc-en|p|ɛ|n|t}}
| style="text-align:left;" | unbipentium
|-
|'''6'''||hex||Greek ''hex'' ("six")||'''h'''||{{IPAc-en|h|ɛ|k|s}}
| style="text-align:left;" | unbihexium
|-
|'''7'''||sept||Latin ''septem'' ("seven")||'''s'''||{{IPAc-en|s|ɛ|p|t}}
| style="text-align:left;" | unbiseptium
|-
|'''8'''||oct||Latin ''octo'' ("eight")<br/>Greek ''okto'' ("eight")||'''o'''||{{IPAc-en|ɒ|k|t}}
| style="text-align:left;" | unbioctium
|-
|'''9'''||en(n)||Greek ''ennea'' ("nine")||'''e'''||{{IPAc-en|ɛ|n}}
| style="text-align:left;" | unbiennium
|-
|'''Suffix'''||-(i)um||Latin ''-um'' (neuter singular)||none||{{IPAc-en|-|i|ə|m}}
|-
|colspan=7 |
* 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''.
:Example 1: element 122: ''[[unbibium]]'' (Ubb)
:Example 2: element 123: ''[[unbitrium]]'' (Ubt)
* If ''enn'' is followed by ''nil'' (i.e. the sequence -90- occurs), the result is ''-ennil-'', not ''-ennnil-''.
:Example 3: element 190: ''unennilium'' (Uen)
|}

{{As of|2019}}, all 118 discovered elements have received individual permanent names and symbols.<ref name="IUPAC-Nov2016">{{cite web
 | url         = https://iupac.org/iupac-announces-the-names-of-the-elements-113-115-117-and-118
 | title       = IUPAC Announces the Names of the Elements 113, 115, 117, and 118
 | date        = 2016-11-30
 | publisher   = IUPAC
 | access-date  = 2016-11-30
}}</ref> Therefore, systematic names and symbols are now used only for the undiscovered elements beyond element 118, oganesson. When such an element is discovered, it will keep its systematic name and symbol until its discovery meets the criteria of and is accepted by the [[IUPAC/IUPAP Joint Working Party]], upon which the discoverers are invited to propose a permanent name and symbol. Once this name and symbol is proposed, there is still a comment period before they become official and replace the systematic name and symbol.

At the time the systematic names were recommended (1978), names had already been officially given to all elements up to atomic number 103, [[lawrencium]]. While systematic names were given for elements 101 ([[mendelevium]]), 102 ([[nobelium]]), and 103 (lawrencium), these were only as "minor alternatives to the trivial names already approved by IUPAC".<ref name=qmul/> The following elements for some time only had systematic names as approved names, until their final replacement with trivial names after their discoveries were accepted.

{| class="wikitable sortable" style="text-align:center"
! rowspan=1|''[[Atomic number|Z]]''
! colspan=2|Systematic
! colspan=2|Formal
! colspan=2|Year
|-
!
! Symbol
! Name
! Symbol
! Name
! Undisputed synthesis first published
! Named
|-
! 104
| Unq
| Unnilquadium
| Rf
| [[Rutherfordium]]
| 1969
| 1997
|-
! 105
| Unp
| Unnilpentium
| Db
| [[Dubnium]]
| 1970
| 1997
|-
! 106
| Unh
| Unnilhexium
| Sg
| [[Seaborgium]]
| 1974
| 1997
|-
! 107
| Uns
| Unnilseptium
| Bh
| [[Bohrium]]
| 1981
| 1997
|-
! 108
| Uno
| Unniloctium
| Hs
| [[Hassium]]
| 1984
| 1997
|-
! 109
| Une
| Unnilennium
| Mt
| [[Meitnerium]]
| 1982
| 1997
|-
! 110
| Uun
| Ununnilium
| Ds
| [[Darmstadtium]]
| 1995
| 2003
|-
! 111
| Uuu
| Unununium
| Rg
| [[Roentgenium]]
| 1995
| 2004
|-
! 112
| Uub
| Ununbium
| Cn
| [[Copernicium]]
| 1996
| 2010
|-
! 113
| Uut
| Ununtrium
| Nh
| [[Nihonium]]
| 2004
| 2016
|-
! 114
| Uuq
| Ununquadium
| Fl
| [[Flerovium]]
| 1999
| 2012
|-
! 115
| Uup
| Ununpentium
| Mc
| [[Moscovium]]
| 2004
| 2016
|-
! 116
| Uuh
| Ununhexium
| Lv
| [[Livermorium]]
| 2000
| 2012
|-
! 117
| Uus
| Ununseptium
| Ts
| [[Tennessine]]
| 2010
| 2016
|-
! 118
| Uuo
| Ununoctium
| Og
| [[Oganesson]]
| 2006
| 2016
|}

== See also ==
* [[Mendeleev's predicted elements]] – a much earlier (1869) system of naming undiscovered elements

== References ==
{{Reflist}}

== External links ==
*{{cite report |url= http://old.iupac.org/reports/provisional/abstract04/RB-prs310804/Chap3-3.04.pdf |title= IUPAC Provisional Recommendations: IR-3: Elements and Groups of Elements |date= March 2004 |publisher= [[IUPAC]] }}

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[[Category:Naming of chemical elements]]
[[Category:Chemical nomenclature]]
[[Category:Periodic table]]