This guideline documents an English Wikipedia naming convention. It is a generally accepted standard that editors should attempt to follow, though occasional exceptions may apply. Any substantive edit to this page should reflect consensus. When in doubt, discuss first on the talk page.

Shortcuts WP:CHEMNAME WP:NCCHEM WP:MOSCHEM/NAME

From Wikipedia:Naming conventions:

Generally, article naming should give priority to what the majority of English speakers would most easily recognize, with a reasonable minimum of ambiguity, while at the same time making linking to those articles easy and second nature.

Trivial names (non-systematic, or "common" names) are favored for use in titles of articles for organic compounds instead of systematic names. Trivial names are usually different from the preferred name following IUPAC nomenclature. For compounds lacking trivial names, as is often the case for complex structures, substitutive nomenclature or other systematic names may be used. The general rule is to use the name most commonly used to refer to the compound, as evidenced by use in reliable sources (in line with WP:COMMONNAME).

Classes of compounds may have more specific guidance on naming, such as the use of international nonproprietary names for pharmaceutical compounds (see WP:NCMED and below).

Examples of use of trivial names and not systematic names include:

Systematic and other accepted names for the compound not used as the article title should instead be redirects tagged with the {{R from alternative name}} template and listed in the chembox as other names, with especially significant alternative names mentioned in the lede in bold font.

Groups

• The groups of the periodic table are numbered left to right as 1–18, with the f-block groups (columns) unnumbered. As recommended by IUPAC (1988).

Note that "group" has a chemical meaning and "column" has the tabular meaning.

• Alternatively, they may be named by their first element, e.g. "boron group" for group 13. (But per below, avoid iron group for group 8 as ambiguous.)
• In the 1–18 scheme, f-block groups are unnumbered. There is no widely-agreed system of numbering these groups in the literature, so one should not be used.

Avoid labeling these groups as n/a (for not applicable?, or not available i.e. "not found yet"?). Best is to leave this group number blank. Provide textual description when needed. This also applies to any (theoretical) g-block groups.

To refer to such a group (column), list the elements explicitly, e.g. ytterbium and nobelium. Do not name by first element (ytterbium group). The reasons for this are that many of the expected first-element names have other meanings as rare earth separation groups (see "Non-column groups" below), and that referring to individual f-block groups in the literature is rare (so it's better to be explicit).

• Hydrogen belongs to group 1 (not group 17 or floating outside all groups), and helium belongs to group 18 (not group 2).
• "halogen" and "noble gas" are used to refer to the entirety of groups 17 and 18, per a 2016 IUPAC report about naming new elements Some sources focusing on superheavy elements may not consider tennessine (Ts) to be a halogen, or oganesson (Og) to be a noble gas, as their predicted chemistry is generally supposed to be quite different from those of their lighter congeners. Such more limited usage should be explained before its first occurrence.
• A few groups have IUPAC-approved names, called trivial name, that may also be used:

alkali metal = group 1 except hydrogen

alkaline earth metal = group 2

triels = group 13

tetrels = group 14

pnictogen = group 15 (earlier pentels)

chalcogen = group 16

halogen = group 17

noble gas = group 18

• Triels (group 13), tetrels (group 14) and pentels (group 15) have been previously recommended by IUPAC (in 1970), and the former two are still used by them, though they are not in the most recent Red Book. Avoid rarer synonyms like icosagen (group 13) and crystallogen (group 14).
• Avoid coinage metal for group 11, since "metal used for making coins" (see coinage metal) contains also metals outside of group 11, and roentgenium in group 11 is (for obvious reasons) not used for coins.
• The group numberings with Roman numbers and "A" and "B" suffixes (like VIIA, VIII) should not be used, as they are outdated and ambiguous. For example, in the CAS scheme "group VIIB" denotes manganese group (group 7), while in the old IUPAC scheme it denotes halogen group (group 17). If they are used at all, context should clarify (disambiguate) into the 1–18 numbering. Care should be taken when translating old sources that use this nomenclature to modern terminology.
• Some sets of groups have names:
  • The main group elements are the elements of groups 1, 2, and 13–18 (i.e. the s-block and p-block).
  • The transition elements are the elements of groups 3–12 (i.e. the d-block) – this in particular includes group 12 (although some sources do not include it).
  • The inner transition elements are f-block elements.

The scandium group (group 3)

• The scandium group should by default be treated as containing the elements scandium (Sc), yttrium (Y), lutetium (Lu), and lawrencium (Lr). Lanthanum (La) and actinium (Ac), which in some sources take the positions of lutetium and lawrencium (especially in older sources), should not be in group 3. Care should be taken when employing sources that mention "group 3" or "group IIIB" or "group IIIA", since they may not always use this arrangement.

This group 3 set is established per the 1988 IUPAC report and per a subsequent 2021 provisional report by a IUPAC project dedicated to this constitution question

In fact, the old classification was based on erroneous early measurements of electron configurations, and was already criticised as "incorrect" by Lev Landau and Evgeny Lifshitz in 1948. The IUPAC report convention is accepted by most chemists and physicists considering the subject.

Note that the so-called "IUPAC(-published) periodic table" is not actually approved by IUPAC. It leaves the spaces below yttrium blank, and there is significant confusion among (and within) sources on whether that includes the lanthanides and actinides in group 3 or not; hence this form is also best avoided.

• Alternative compositions of group 3 may be illustrated when describing the dispute, e.g. in Group 3 element#Composition.

Non-column groups

• In case of commonly named "groups" that are not a column, such as Platinum group or Iron group, care should be taken that no confusion remains with column-wise periodic table group.

18 vs 32 columnsedit

• The periodic table can be displayed in either 18- or 32-column format, with the 32-column format as in Fig. 4 of the aforementioned 2021 IUPAC report. The forms present the same scientific statement and should be consistent with each other. The 18-column format cuts out the f-block rows, containing the elements lanthanum (La) through ytterbium (Yb) and actinium (Ac) through nobelium (No), and places them at the bottom of the table.¹ Asterisks should be placed between groups 2 and 3 to indicate the theoretical position of these cut-out rows.

Note that these f-block rows do not equal the lanthanides/lanthanoids (La–Lu) and actinides/actinoids (Ac–Lr) which commonly extend to include lutetium and lawrencium.

• Other structures, e.g. the Janet left-step or the 8-group form, should only be used when specifically illustrating such alternative periodic tables.

Blocksedit

At this English wiki, the preferred presentation coloring scheme of the elements is by blocks (s, p, d, or f).

The colours to be used are given in {{Element color}}:

•    s-block → #ff9999 
•    p-block → #fdff8c 
•    d-block → #99ccff 
•    f-block → #9bff99 

This template also gives colours for the higher orbitals:

•    g-block → #fd99ff 
•    h-block → #7ed9d9 
•    i-block → #e0c880 

Categorising elementsedit

Categorisation is an attempt to classify all elements into one overall scheme, with each element in exactly one category (as opposed to listing non-completifying sets like coinage metals). A general classification is not achieved in sources (let alone without WP:NPOV and WP:OR). Such categorisation then is not to be used in general (for example, not as general coloring of the periodic table).

A general colouring by metallicity is discouraged, because there are WP:NPOV and WP:NOR concerns: the borders of some categories can differ drastically between sources (e.g. metalloids), and there is no set of categories that are mutually exclusive and yet cover the entire periodic table (e.g. astatine is quite likely to be both a metal and a halogen). However, such coloring may be used to base and illustrate dedicated topics (such as in sections of metalloids). Individual, well-established "metallicity" categories, e.g. transition metal, post-transition metal, metalloid, rare earth metals etc., can be referred to without "all elements all once" colouring.

When a specific categorisation scheme is relevant (e.g. {{ChemicalBondsToCarbon}}), a periodic table-filling categorisation can be applied.

Traditionally, the names of three elements have been spelled differently in different parts of the English-speaking world. For articles about chemistry-related topics, Wikipedia follows the spellings recommended by the International Union of Pure and Applied Chemistry (IUPAC):¹²²

These spellings should be used in all chemistry-related articles on English Wikipedia, even if they conflict with the other national spelling varieties used in the article.

This convention should also be applied to all compounds and derivative names of these chemicals: sulfate not sulphate; sulfuric not sulphuric; etc.

The English name of element 74 is tungsten and not wolfram: the latter was once adopted by IUPAC (in 1949), but is no longer recommended by them (even as an alternative) per the 2011 Principles. (Of course, the symbol is still W, and the name "wolfram" may be referred to when explaining why that is the case, or when quoting text in languages that use that name.) Similarly for derivatives (per the 2005 Red Book), use tungstate, tungsty, tungsta and not wolframate, wolframy, wolframa. (And similarly avoid the old names emanation and niton for element 86 outside historical contexts; there is a real confusion even in today's literature between radon meaning the element Rn and radon meaning the isotope ²²²Rn, but the way to solve that is by explicitly clarifying what is meant, not resurrecting archaic terms that have fallen out of use and may not be generally understood.)

Elements that have not been given trivial names by IUPAC may be referred to either by IUPAC systematic element names and symbols, or by atomic numbers. So ununennium and element 119 are both correct, and symbols Uue, 119, E119 may all be used in text. However, for natural disambiguation, the article titles should be at the systematic names.

When new elements are recognised, do not change the names and symbols to those proposed by the discoverers until the public comment period expires and IUPAC makes the final announcement! (The symbol has changed between the initial proposal and the final recommendation before, in the case of copernicium: originally proposed as Cp, but became Cn.)

Isotope namesedit

• Isotopes are named and identified as element-mass number with regular lowercase and hyphen (carbon-13), or by equivalent symbol format ¹³C (in wikicode: <sup>13</sup>C). Avoid 13C, C-13, C¹³ (and avoid like single character U+2074 ⁴ SUPERSCRIPT FOUR, as used in Wikidata).
• Metastable states are noted by format tantalum-180m1, ^180m1Ta. The number ⟨¹⟩ can be omitted when there is only one isomeric state, e.g. tantalum-180m, ^180mTa. You may use a nuclide template. Corresponding letters also used in literature, these are not used in this wiki: ⟨^m n p q⟩.
• The hydrogen isotopes are exceptions where the common special names may be used:
  • Protium (= hydrogen-1, ¹H).
  • Deuterium, D, ²D (= hydrogen-2, ²H).
  • Tritium, T, ³T (= hydrogen-3, ³H).
• Chemical formulae with deuterated solvents (for example, in NMR use) are customarily described with "D" as chemical symbol: CD₃OD, methanol-d₄; CD₃SOCD₃, DMSO-d₆ (regular notation would be C²H₃O²H). These established systems are acceptable, provided they are consistent within an article.

• Some isotopes have had historical or confusing names and symbols, these are to be avoided (except when quoting historical usage): e.g. thoron (Tn) (²²⁰Rn), actinon (An) (²¹⁹Rn), ionium (Io) (²³⁰Th), radiocarbon (¹⁴C).

• It is permissible to use the atomic number rather than the symbol in contexts about history when anachronism is to be avoided, e.g. "In 2003, the collaboration at the JINR discovered ²⁸⁸115 and ²⁸⁴113" (because at that point those elements had not yet been named). But this should be avoided outside talking about history. Avoid using the systematic element names in such contexts even when talking about history, because they are not supposed to be used once the element actually has a trivial name. For isotopes of undiscovered elements, either systematic names (e.g. ²⁹⁶Uue) or atomic numbers (e.g. ²⁹⁶119) are acceptable for the symbols, but only the systematic names can be used for the full names (e.g. ununennium-296, not element 119-296 which nobody uses).

Main isotopesedit

Currently under discussion for addition

See WT:ELEMENTS:What is a "Main_isotope"?

Elements with atomic number Z ≥ 119 are theoretical elements, they have not been discovered (synthesized). Regarding public-page creation and content (reader-visible pages, such as artricle, category, template):

• Element page: Articles pages, by systematic name, exist for E119 up to E184: Ununennium (Element 119).

These are either full articles (like Ununennium) or redirects (like Unbitrium, 58 redirects). This serves readers searching for these element names.

• Redirect element articles like Unbitrium (Element 123) R:

Per WP:notability and WP:Reliable sources, these articles can and may only be created with content when substantial information is available.

• Secondary public pages for element articles, like Isotopes of unbioctium, {{Infobox unbioctium}}, :Category:unbioctium:

These can and may only be created (1) when the base element article exists by content, and (2) when substantial new RL information like papers is available. These secondary pages may not be created as redirect.

To compare: Disovered element Oganesson (E118) has its article, plus all five secondary articles; none is a redirect.

As of 4 Jan 2023^update: Effectively this means that currently public-page creation, by content or redirect, is not permitted nor needed. See also documentation at Template:Infobox element § Theoretical elements handling.

The names of elements and other chemicals should be written without abbreviations and treated as common nouns. They do not have special capitalization or italic formatting (see MOS:CAPS and MOS:ITALIC) regardless of the origin of the name unless appropriate for the start of a sentence or part of a title. The symbols for elements should always be capitalized. Zdroj:https://en.wikipedia.org?pojem=Wikipedia:Naming_conventions_(chemistry)
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