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 and Transfermium Wars). 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 | pronunciation |
---|---|---|---|
0 | nil | n | /nɪl/ |
1 | un | u | /uːn/ |
2 | b(i) | b | /baɪ/ |
3 | tr(i) | t | /traɪ/ |
4 | quad | q | /kwɒd/ |
5 | pent | p | /pɛnt/ |
6 | hex | h | /hɛks/ |
7 | sept | s | /sɛpt/ |
8 | oct | o | /ɒkt/ |
9 | en(n) | e | /ɛn/ |
Suffix | -ium | none | /iːəm/ |
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 suffix -ium. Some of the roots are Latin and others are Greek; the reason is to avoid two digits starting with the same letter (Ex: 0 = nil, 9 = enn, 4 = quad, 5 = pent, 6 = hex, 7 = sept) . 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, as well as elements 114 and 116, have received individual permanent names and symbols. So the systematic names and symbols are only used for unnamed elements 113, 115, 117, 118, and higher. The systematic names are exactly those with 3-letter symbols.
Notes
Element 122 un + bi + b + ium = unbibium (Ubb) (instead of "unbibiium") Element 167 un + hex + sept + ium = unhexseptium (Uhs) (instead of "unsexseptine") Element 190 un + en + nil + ium = unennilium (Uen) (instead of "unennnilium", or "unnonanilium") Note: These examples show conjectured elements.
As of 2015, ununoctium, element 118, is the highest-numbered element discovered.
Examples in Period 8 of the periodic table:
Period 8 in the extended periodic table based on the Aufbau principle | ||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Period 8 | 119 Uue |
120 Ubn |
121 Ubu |
122 Ubb |
123 Ubt |
124 Ubq |
125 Ubp |
126 Ubh |
127 Ubs |
128 Ubo |
129 Ube |
130 Utn |
131 Utu |
132 Utb |
133 Utt |
134 Utq |
135 Utp |
136 Uth |
137 Uts |
138 Uto |
139 Ute |
140 Uqn |
141 Uqu |
142 Uqb |
143 Uqt |
144 Uqq |
145 Uqp |
146 Uqh |
147 Uqs |
148 Uqo |
149 Uqe |
150 Upn |
151 Upu |
152 Upb |
153 Upt |
154 Upq |
155 Upp |
156 Uph |
157 Ups |
158 Upo |
159 Upe |
160 Uhn |
161 Uhu |
162 Uhb |
163 Uht |
164 Uhq |
165 Uhp |
166 Uhh |
167 Uhs |
168 Uho |
s-block | g-block | f-block | d-block | p-block |
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