View source for Wikipedia:WikiProject Elements/Guidelines

{{Wikipedia:WikiProject Elements/header}}
{{Historical}}
'''<big>Article structure guidelines</big>'''

With a few suggestions for unified phrasings. (Note that the coding of headings is different only for this illustration, the usual article editing guidelines apply.)
(_ElementDescription_ is something like: "silvery and ductile member of the post-transition metal group of chemical elements.")
{{seealso|Wikipedia:Manual of Style (chemistry)/Elements/draft}}
<div style="border:1px solid; padding:0.5em">
'''__''' is a _ElementDescription_.  Its symbol is '''__''' and its [[atomic number]] is __.

:<span style="color:gray">Or alternatively for short-lived synthetic elements:</span>
'''__''' is a [[synthetic element]] in the [[periodic table]] that has the symbol __ and [[atomic number]] __.

== Characteristics ==
=== Physical ===
:<span style="color:gray">Describe the basic properties of the ''element'' (not its compounds) in everday life: physical state (we assume STP), electrical/thermal conductivity, color.  Follow this part with more complex content such as ionization potentials, electron configuration, heat of vapourization, etc. If there a lot to say about any one item, say allotropes, then a separate ===Allotropes=== subsection would probably be helpful.</span>

=== Chemical ===
:<span style="color:gray">Reactions of the ''element'' (principal compounds comprise a ''separate'' section).  Reactions with water, air (corrosion), redox potential of the element.</span>

=== Isotopes ===
:<span style="color:gray">Discuss isotopes per suggested boilerplate text below. If appropriate, also discuss [[nucleosynthesis]] in stars / nova.</span>
{{main|Isotopes of X}}

Naturally occurring _ is composed of _ stable [[isotope]]s, _-_, _-_, and _-_, with _-_ being the most abundant (_% [[natural abundance]]).<ref name = "NNDC">
{{cite web
 | url = http://www.nndc.bnl.gov/chart/
 | author = NNDC contributors
 | editor = Alejandro A. Sonzogni (Database Manager)
 | title = Chart of Nuclides
 | publisher = National Nuclear Data Center, [[Brookhaven National Laboratory]]
 | access-date = 2008-09-13
 | year = 2008
 | location = Upton (NY)
}}</ref> Out of these, _ are of use in [[NMR]] and [[EPR spectroscopy]].<ref>http://www.nyu.edu/cgi-bin/cgiwrap/aj39/NMRmap.cgi</ref>  _ [[radioisotope]]s have been characterized, with the most {abundant and/or stable} being _-_ with a [[half-life]] of _, _-_ with a half-life of _, and _-_ with a half-life of _.<ref name = "NNDC"/>  All of the remaining [[Radioactive_decay|radioactive]] isotopes have half-lives that are less than _, and the majority of these have half lives that are less than _.<ref name = "NNDC"/> This element also has _ [[nuclear isomer]]s, with the longest-lived being _m-_ (t<sub>½</sub> _), _m-_ (t<sub>½</sub> _) and _m-_ (t<sub>½</sub> _).<ref name = "NNDC"/> The nuclei of nuclear isomers exist in a delicate equilibrium or [[metastability]] due to at least one nucleon having an [[excited state | excited energy state]].

<span style="color:gray">The isotopes of _ range in [[mass number]] from _ to _ .<ref name = "NNDC"/> The most common [[decay mode]](s) of _ isotopes with mass numbers lower than the most abundant stable isotope, _-_, is/are [[{name of decay mode}]] /and [[{name of decay mode}]], primarily forming _ isotopes (_ protons) /and _ isotopes (_ protons) as [[decay product]]s.<ref name = "NNDC"/> The most common decay mode(s) for _ isotopes with mass numbers higher than _-_, are [[{name of decay mode}]] /and [[{name of decay mode}]]. primarily forming _ isotopes (_ protons) /and _ isotopes (_ protons) as decay products.<ref name = "NNDC"/></span>

=== Occurrence ===
:<span style="color:gray">Amount of element in ... the solar system, earth, crust, water, atmosphere, humans and other organisms (as available and appropriate). Discuss ores and minerals, mentioning global reserves.</span>

== Production ==
<div style="color:gray">
:Not needed for elements that are not extensively mined, refined or used. Mention mining amounts, extraction techniques and amount of pure element or other derivatives produced ''for'' industry each year here. Also mention any environmental/pollution issues associated with the processing.

:Information about the price is usually placed at the bottom of this section. Specify ''as of when'' is the information. Where applicable, state purity or type and use relevant industry standard units for currency and amount (example: [[U.S. Dollar|US$]] per [[troy ounce]] for [[gold]]). Indicate trends and provide a link to a live source where possible. Information about many commodities is available at [http://minerals.usgs.gov/minerals/pubs/commodity/index.html] for example.
</div>

== Compounds ==
:<span style="color:gray">This section is longer than ===chemical characteristics=== above, which is largely restricted to the element (otherwise these sections are semi-redundant).  Main binary compounds should be discussed; separating them by oxidation state.  Comments on geometry, magnetism and a feel for the reactivity. Aqueous behavior toward bases and acids (i.e. the element-ATE ions).  Where appropriate, separate section on organic/organometallic derivatives (for most elements, an article exists on "organo... compound", so <nowiki>{{main|organo...}}</nowiki> is indicated.</span>
:<span style="color:gray">section with subsections and possibly a Main Article link to a "Compounds of ..." daughter article.</span>

== History ==
:<span style="color:gray">If the element was not known to the ancients, then mention who discovered it (and/or its oxide) and how (mention other contributors as well). If known by the ancients, then mention by what cultures, when first used (best evidence) and what the element was used for. Briefly mention major historical uses of the element and its major oxides (if applicable). Mention any notable use by alchemists and provide an image of alchemical symbol. A portrait of the discoverer should probably be included.  Other major developments should be summarized such as technologies for the extraction or utilization.</span>

== Applications ==
:<span style="color:gray">Ranked in order of usage, ideally with graphic (pie-chart) showing use-fractions.  ''Most'' real-world applications are prosaic and might not appeal to many academic editors. Most metals are used as the metals, not compounds.  Laboratory reagents consume negligible amounts of production stream, so this content should not be allowed to dominate.  Enumerating other niche uses similarly can overwhelm almost any article (e.g. copper is used to make door knobs).  Avoid lists.</span>

:<span style="color:gray">There's always some tension between the largest uses of an element, and how much to write about them. For example, 93% of world potassium production is for fertilizer, but 93% of the [[potassium#Applications]] should ''not'' be about fertilizer! Similarly, bio-centric/medicinal uses of an element merit attention well-beyond beyond their use-fractions.</span>

== Biological role ==
:<span style="color:gray">Approximately 20 elements are required by higher organisms. Discuss how the element is used in organisms (prominent enzymes/proteins) and how the element manifests itself.  Discuss how a deficiency of the element affects health. Toxic effects should be placed in the <nowiki>==Precautions==</nowiki> section.</span>

== Precautions ==
{{NFPA 704|H=-|F=-|R=-|S=RA}}
:<span style="color:gray">Discuss toxic effects and amount needed to be toxic to humans and other organisms.  Mention handling standards and notable accidents involving improper handling (if not already mentioned in ==History== section). Any mention of deliberate use as a toxin should go in the ==Applications== section. Particularly toxic elements should include an [[NFPA 704]] diagram ("fire diamond", template {{tl|NFPA 704}} box). Note that extensive toxicity and hazard material is available to casual editors, so this section is reserved for highly notable information, e.g. arsenic is highly toxic, but we do not discuss that combining sodium and water is dangerous (that would go into the chemical characteristics section).</span>

{{clear}}

== Notes ==
:<span style="color:gray">Only needed if <nowiki><ref group="note">explanatory note here</ref></nowiki> is used to add inline footnotes to provide more detailed explanations that would otherwise disturb the flow of the prose. They are rarely needed.</span>

== References ==
:<span style="color:gray">Place <nowiki><references/></nowiki> here. This section will automatically list all inline citations using the <nowiki><ref></ref></nowiki> markup.  Especially for articles on elements, references are reserved for texts, monographs, review series.  Primary journals are cited mainly to illustrate points.</span>
<references/>

:<span style="color:gray">May include, not all links applicable everywhere:</span>

== Bibliography ==
:<span style="color:gray">References are ''mainly'' reserved for ''major texts, monographs, review series''. Primary journals are cited mainly to illustrate points.  List all multipage reference works that are cited multiple times on different pages here. Inline cites in the prose that reference works listed here need to indicate author's last name, year of publication and page number. Example: Weeks 1933, p. 22. The {{tl|harvnb}} template could also be used to give. {{harvnb|Weeks|1933|p=22}}</span>
*<!-- CRC -->{{cite book
 | author = CRC contributors
 | title = Handbook of Chemistry and Physics
 | editor = David R. Lide
 | edition = 87th
 | year = 2006
 | publisher = CRC Press, Taylor & Francis Group
 | location = Boca Raton, Florida
 | isbn = 0-8493-0487-3
 | ref = CITEREFCRC2006}}
*<!-- Em -->{{cite book
 | title = Nature's Building Blocks: An A-Z Guide to the Elements
 | last = Emsley
 | first = John
 | publisher = Oxford University Press
 | year = 2001
 | location = Oxford, England, UK
 | isbn = 0198503407
 | chapter =
 | pages = 
 }}
*<!-- Sw -->{{cite book
 | title = Guide to the Elements
 | edition = Revised
 | first = Albert
 | last = Stwertka
 | publisher = Oxford University Press
 | year = 1998
 | chapter = 
 | pages=
 | isbn = 0-19-508083-1
 }}
*<!-- Gr -->{{cite book
 | last = Greenwood
 | first = N. N.
 | last2 = Earnshaw | first2 = A.
 | title = Chemistry of the Elements
 | edition = 2nd
 | publisher = Butterworth-Heinemann
 | location = Oxford
 | year = 1997
 | isbn = 0-7506-3365-4
 | page = 
 | chapter =
 }}
*<!-- {A} -->{{cite book
 | title = The Encyclopedia of the Chemical Elements
 | publisher = Reinhold Book Corporation
 | location = New York
 | year = 1968
 | editor = Clifford A. Hampel
 | id = LCCN 68-29938
 | last = {Author}
 | first = 
 | chapter = 
 | pages= 
 }}
*<!-- He -->{{cite book
 | last = Heiserman
 | first = David L.
 | title = Exploring Chemical Elements and their Compounds
 | location = New York
 | publisher = TAB Books
 | isbn = 0-8306-3018-X
 | chapter = Element 00: ElementName
 | pages=
 }}
* <!-- We -->{{cite book
 | last = Weeks
 | first = Mary Elvira
 | author-link = Mary Elvira Weeks
 | year = 1933
 | title = The Discovery of the Elements
 | publisher = Journal of Chemical Education
 | location = Easton, PA
 | chapter = 
 | pages = 
 | isbn = 0766138720
 }}
- _

</div>

;Notes on some common references

*<!-- Hu --><cite id=LANL>{{cite web|title=ElementName|url=http://periodic.lanl.gov/1.html|publisher=Los Alamos National Laboratory|date=2003-12-15|work=Periodic Table of the Elements|last=Husted|first=Robert}}</cite>
:<span style="color:gray">Even though this text was paid for by CA State and US Federal tax dollars, the UC Regents claims a restrictive copyright so it is ''not'' public domain and therefore cannot be copied. Instead, use it as any other reference. In addition, the LANL periodic table hasn't been touched since 1997 but it has won several awards.</span>
* http://minerals.usgs.gov/minerals/pubs/commodity/{element_name,lowercase}/ USGS _
:<span style="color:gray">Statistics and Information This is public domain material and can be copied verbatim but it isn't available for every element. The text may also be under a different name. They sometimes combine entries, such as iron and steel. If nothing comes up, then look for the element at http://minerals.usgs.gov/minerals/pubs/commodity/ .</span>
* http://wwwrcamnl.wr.usgs.gov/isoig/period/{element_symbol,lowercase}_iig.html USGS
:<span style="color:gray">Periodic Table - _ This is public domain isotope info and ''can'' be copied verbatim but it is very technical and usually only the first paragraph or two are useable at all (the focus of the USGS period table is hydrology and we needn't fill our period table with material that is that specialized). Not all elements are included in this source.</span>
*<!-- Kr --><cite id=Krogt>{{cite web
 | title={ElementName}
 | url=http://elements.vanderkrogt.net
 |last=van der Krogt |first=Peter
 |year=2005
 |work=Elementymology & Elements Multidict}}</cite>
:<span style="color:gray">Can't be used directly because it is self-published work and thus not a [[WP:RS|reliable source]], but a good starting point to get oriented about an elements discovery and naming. Any info obtained from that website ''must'' be independently verified and cited to the alternate, more reliable, source. Luckily, van der Krogt is pretty good and citing sources.</span>
*http://www.columbia.edu/cu/chemistry/groups/parkin/mlxz.htm
:<span style="color:gray">Is a good and reliable starting point for the chemistry sections of transition metals.</span>
*http://sis.nlm.nih.gov/sitemapsearch.html
:<span style="color:gray">Good for precautions issues.</span>
*http://onlinelibrary.wiley.com/book/10.1002/14356007/homepage/WhatsNew.html
:<span style="color:gray">Ullman's Encyclopedia of Industrial Chemistry.</span>
*http://www.roskill.com/

:<span style="color:gray">Is a good review for some metals and minerals.</span>

== Reference data pages ==
Any changes to the infobox data should be checked against these pages, and/or the available references should be expanded accordingly, so that the decision for or against certain values remains transparent and easily retraceable.
* [[List of data references for chemical elements]]
=== Previous data sources ===
The earlier guide for acquiring the data included these sources:
:NOTE: <s>struck items</s> are explicitly no longer recommended for use for any data in element articles. When found, these references should be replaced by more reliable sources.
* <s>http://www.WebElements.com/ for series, period, block, density, appearance, atomic weight, atomic/covalent/van der Waals radii, electron configuration, electrons per energy level, state of matter at STP, melting and boiling point at SP, molar volume, velocity of sound, ionization potentials.</s>
* <s>http://EnvironmentalChemistry.com/ for hardness (Mohs), oxidation states, crystal structure, heats of vaporization/fusion, vapor pressure, electronegativity, specific heat capacity, electrical conductivity, thermal conductivity, nuclides.</s>
:The recommendation regarding which nuclides should be included in the infobox table has been: "Choose all the stable forms and only a ''small'' selection of the most stable radioisotopes."
* http://chemlab.pc.maricopa.edu/periodic/periodic.html for "oxide is (...)", heats of vaporization/fusion (alternate source).
* http://www.allmeasures.com/Formulae/static/materials/ for velocity of sound (alternate source), specific heat capacity (alternate source).

== Color standards ==

[https://en.wikipedia.org/w/index.php?title=Wikipedia:WikiProject_Elements/Guidelines&oldid=532729988#Color_standard Link to superseded standards] (2013) for historical reference purposes. [[User:Sandbh|Sandbh]] ([[User talk:Sandbh|talk]]) 04:20, 11 June 2017 (UTC)

{{Wikipedia:WikiProject Elements/Legends}}

== Blocks ==
{{Periodic table legend|child=no|caption=Block
|theme1=Block|predicted1=yes|sa1=yes|eka-sa1=yes|unknown1=yes}}

{| class="wikitable collapsible uncollapsed"
! colspan=5 | Periodic table: block legend colors (enwiki, 25 July 2014)<br><small>(The earlier set had the colors yellow-green swapped. That was during July 12&ndash;July 25 2014 only)</small>
|-
! s
! p
! d
! f
! g
|-
| style="background:#ff9999" | s-block<br>[[Main Page]]<br><code>#ff9999</code><br>HSV=0-40-100<br>red
| style="background:#fdff8c" | p-block<br>[[Main Page]]<br><code>#fdff8c</code><br>HSV=17-45-100<br>yellow
| style="background:#99ccff" | d-block<br>[[Main Page]]<br><code>#99ccff</code><br>HSV=58-40-100<br>blue
| style="background:#9bff99" | f-block<br>[[Main Page]]<br><code>#9bff99</code><br>HSV=33-40-100<br>green
| style="background:#fd99ff" | g-block*<br>[[Main Page]]<br><code>#fd99ff</code><br>HSV=83-40-100<br>purple
|-
| colspan=5 | Element is in block, '''theoretically or predicted''':
|-
| style="background:#ffcccc" | s-block (predicted)<br>[[Main Page]]<br><code>#ffcccc</code>
| style="background:#ffffbf" | p-block (predicted)<br>[[Main Page]]<br><code>#ffffbf</code>
| style="background:#cce7ff" | d-block (predicted)<br>[[Main Page]]<br><code>#c7eeff</code>
| style="background:#cdffcc" | f-block (predicted)<br>[[Main Page]]<br><code>#cdffcc</code>
| style="background:#febfff" | g-block (predicted)<br>[[Main Page]]<br><code>#febfff</code>
|-
| colspan=5 | <nowiki>*</nowiki> Elements "in g-block" exist theoretically (predicted) only<br>(this g-block darker color is not used, but here for color calculations)
|-
| colspan=5 | Colors determined in HSV color space, numbers in %. Per column, Hue (the "H" in HSV) is kept; "S" is ~halved from 40%→20%, "V"=100%
|-
| colspan=5 | Contrast is checked against black font and blue font (<code>#0b0080</code>, wiki bluelink color). All are: AA=OK, AAA=OK. Not checked against other font colors.
|-
| colspan=5 | Version: introduced on enwiki ''25'' July 2014 (before, other color schemes were used on enwiki)
|-
| colspan=5 | See also:<br>
* [[:commons:File:Periodic table blocks spdf (32 column).svg]]
|}

== State of matter, Occurrence ==
{{Periodic table legend|child=no|caption=State of matter|State of matter
|theme1=State of matter|predicted1=yes|sa1=yes|eka-sa1=yes|unknown1=yes}}

{{Periodic table legend|child=no|caption=Occurrence
|theme1=Occurrence|predicted1=yes|sa1=yes|eka-sa1=yes|unknown1=yes}}

== Locator map image ==
Currently, the periodic table locator map images are no longer images, but instead are now clickable periodic tables with functionality similar to that of [[Template:Compact periodic table]].

==Notes==
   
{{reflist|group=note}}

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