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 poor metal group of chemical elements.")
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 about any one item, say allotropes, then a separate ===Allotropes=== subsection would probably be helpful.
Chemical
Reactions of the element (principal compounds comprise a separate section). Reactions with water, air (corrosion), redox potential of the element.
Isotopes
Discuss isotopes per suggested boilerplate text below. If appropriate, also discuss nucleosynthesis in stars / nova.
Naturally occurring _ is composed of _ stable isotopes, _-_, _-_, and _-_, with _-_ being the most abundant (_% natural abundance).[1] Out of these, _ are of use in NMR and EPR spectroscopy.[2] _ radioisotopes 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 _.[1] All of the remaining radioactive isotopes have half-lives that are less than _, and the majority of these have half lives that are less than _.[1] This element also has _ nuclear isomers, with the longest-lived being _m-_ (t½ _), _m-_ (t½ _) and _m-_ (t½ _).[1] The nuclei of nuclear isomers exist in a delicate equilibrium or metastability due to at least one nucleon having an excited energy state.
The isotopes of _ range in mass number from _ to _ .[1] 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 products.[1] 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.[1]
Occurrence
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.
Production
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: 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 [1] for example.
Compounds
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 {{main|organo...}} is indicated.
section with subsections and possibly a Main Article link to a "Compounds of ..." daughter article.
History
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.
Applications
Ranked in order of usage. Most real-world applications are prosaic and might not appeal to many academic editors. M ost 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.
Biological role
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 == Precautions== section.
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"). 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).
Notes
Only needed if <ref group="note">explanatory note here</ref> is used to add inline footnotes to provide more detailed explanations that would otherwise disturb the flow of the prose. They are rarely needed.
References
Place <references/> here. This section will automatically list all inline citations using the <ref></ref> markup. Especially for articles on elements, references are reserved for texts, monographs, review series. Primary journals are cited mainly to illustrate points.
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 {{harvnb}} template could also be used to give. Weeks 1933, p. 22
CRC contributors (2006). David R. Lide (editor) (ed.). Handbook of Chemistry and Physics (87th edition ed.). Boca Raton, Florida: CRC Press, Taylor & Francis Group. ISBN0-8493-0487-3. {{cite book}}: |author= has generic name (help); |edition= has extra text (help)
Emsley, John (2001). Nature's Building Blocks: An A-Z Guide to the Elements. Oxford, England, UK: Oxford University Press. ISBN0198503407.{{cite book}}: CS1 maint: ref duplicates default (link)
Stwertka, Albert (1998). Guide to the Elements (Revised Edition ed.). Oxford University Press. ISBN0-19-508083-1. {{cite book}}: |edition= has extra text (help)CS1 maint: ref duplicates default (link)
Greenwood, N. N. (1997). Chemistry of the Elements (2nd ed. ed.). Oxford: Butterworth-Heinemann. ISBN0-7506-3365-4. {{cite book}}: |edition= has extra text (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: ref duplicates default (link)
{Author} (1968). Clifford A. Hampel (ed.). The Encyclopedia of the Chemical Elements. New York: Reinhold Book Corporation. LCCN 68-29938. {{cite book}}: |last= has generic name (help); Cite has empty unknown parameter: |coauthors= (help)CS1 maint: ref duplicates default (link)
Heiserman, David L. "Element 00: ElementName". Exploring Chemical Elements and their Compounds. TAB Books. ISBN0-8306-3018-X. {{cite book}}: Unknown parameter |Location= ignored (|location= suggested) (help)
Weeks, Mary Elvira (1933). The Discovery of the Elements. Easton, PA: Journal of Chemical Education. ISBN0766138720. {{cite book}}: ISBN / Date incompatibility (help)CS1 maint: ref duplicates default (link)
- _
Notes on some common references
Husted, Robert (2003-12-15). "ElementName". Periodic Table of the Elements. Los Alamos National Laboratory.
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.
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/ .
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.
van der Krogt, Peter (2005). "{ElementName}". Elementymology & Elements Multidict.
Can't be used directly because it is self-published work and thus not a 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.
The List of data references for chemical elements is divided into datasheets that give values for many properties of the elements, together with various references. Each datasheet is sequenced by atomic number.
References for chemical elements
List of chemical elements — with basic properties like standard atomic weight, m.p., b.p., abundance
This article includes a science-related list of lists. If an internal link incorrectly led you here, you may wish to change the link to point directly to the intended article.
Previous data sources
The earlier guide for acquiring the data included these sources:
NOTE: struck items are explicitly no longer recommended for use for any data in element articles. When found, these references should be replaced by more reliable sources.
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.
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.
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."
Table headings all have fill colors that match the fill colors used for that element's chemical series in the periodic table. Their text color is black for elements that are solid at ambient conditions, green for liquids, and red for gases. Color scheme and rationale for the table:
Another shade of gray (or even silver) would work here. But that would make the table a bit drab and the colors of the metals and transitions metals too similar.
Non-reactive for practical purposes. Cyan is soft and soothing (it is also the opposite of red).
unknown chemical properties
#e8e8e8
This particular shade of gray usually signifies "unknown". (Note that some obsolete alternatives, such as #f0f0f0, may still be in use; these should be changed to #e8e8e8, as in Template:Periodic table and Template:Compact periodic table.)
undiscovered
#ffffff
White usually signifies "unknown", it being a blank space where the element symbol is floating.
Note that the lanthanides and actinides are also transition metals, and the halogens and noble gases are also nonmetals, but they are not coloured as such for usability.
Locator map image
Currently, the periodic table locator map images are no longer images, but as clickable periodic tables with functionality similar to that of Template:Compact periodic table.
The periodic table locator map images at the top of most infobox tables were 250 pixel wide images (naming scheme "symbol-TableImage.png") created from 890 pixel wide images (named "symbol-TableImage-BIG.png", not all available). Later some but not all "symbol-TableImage.png"s were adapted to use the big version directly and let the Wiki software downscale automatically. A set of these images was uploaded to commons:periodic table.
The font type for the lettering is Helvetica (urw), medium, with unscaled font sizes for the element symbol of 56 and the nucleons of 38, respectively.
The element highlight box should be black, 2 pixels wide and within the element's box.
The images for the different crystal structures are at crystal structure and are already the right size for the large image.
Images of the different shell structures and blocks are already on each of the different period templates.
No part of the images is in English so they may be usable for many languages.
You may also notice a single black dot as a guide near where the element's symbol is supposed to go.
