This is an explanatory essay about Wikipedia:Manual of Style/Chemistry. This page provides additional information about concepts in the page(s) it supplements. This page is not one of Wikipedia's policies or guidelines as it has not been thoroughly vetted by the community.

Shortcut MOS:CHEM/Chemicals

The appropriate infobox to use is ((Chembox)). It is a modular, expandable infobox. Just use the parameters which you need; empty values will not be displayed. Chemboxes should be used for all chemical compounds, so long as they can exist in that form, even for compounds which are not isolable in pure, solvent-free form (e.g. hypochlorous acid). Chemboxes should not be used for ions, polymers, and proteins and enzymes (except simple peptides).

To include a chembox in an article:

1. Open ((Chembox)) and copy the relevant (simple, medium, full) box desired, and paste into a text editor
2. Open the relevant reference (e.g. MSDS, Merck Index, CRC Handbook, etc.) and input the data into the template
3. Copy the filled-out template into the relevant Wikipedia article.

For formatting reasons, the code for the infobox should be at the very beginning of the source code.

Introductory paragraph should classify the compound either generally (organic compound vs inorganic compound) or more specifically (e.g., organometallic compound or organoarsenic compound). A few properties should be described, assuming STP, and noteworthy features should be mentioned (e.g. extreme toxicity, odor, hygroscopicity). For simpler organic compounds, the main functional group is mentioned, whereas for complex molecules, a parent molecule should be mentioned. Alternative names and routine properties (m.p., density) are ordinarily placed in the Chembox, not in the lead.

Articles on chemical compounds differ from most other articles in Wikipedia because many names often apply to any given compound. Therefore all but the most prominent names are placed in the "other names" slot on the ChemBox.

This section is often not needed. A discussion of properties is more important for chemicals encountered in everyday life and for solids, where "collective" properties (magnetism, hardness, conductivity) are important. The properties of small organic molecules can be surmised from data in the Chembox and generally do not require extended discussion. Often this section is combined with a description of structure, which summarizes the molecular structure or crystal packing (for extended solids). Bond distances are quoted in picometers or angstroms.

If the compound occurs naturally, it can be mentioned here. If natural sources are industrially significant, some discussion should be included. Avoid one-sentence sections — such data can be left in the lead.

Articles about chemical compounds should include methods of preparation, usually in this order:

• Industrial production. Production figures give readers a sense of the commercial significance of a compound. Typical sources of such information are trade journals such as Chemical and Engineering News and references sources such as Ullmann's Encyclopedia of Industrial Chemistry.
• Biosynthesis
• Laboratory-scale preparation

Different methods of synthesis/production may merit full-fledged subheadings. Even articles about compounds that are normally extracted from minerals (e.g. molybdenum disulfide) should ideally have a laboratory route to the same compound. Mention should be made if a compound is routinely available commercially.

Where appropriate, the first synthesis/first characterization of each compound is described with a reference to the original article. Apart from that, "foolproof" syntheses such as those listed in Organic Syntheses and Inorganic Syntheses are preferred. Patented syntheses should be phrased carefully — e.g. "xxx may be synthesized from ... " Patents are usually inferior sources owing to their undependable reliability, accessibility, and clarity.

When writing about preparations, remember that Wikipedia is not a manual or textbook. In general, preparations should be described in general terms, not as step-by-step instructions giving specific amounts, times, conditions, equipment, and details such as methods of stirring and separation.

The order of presentation and allocation of content should reflect the scale of the individual applications. Large-scale applications should be listed first. Lay editors will naturally tend to enumerate domestic uses. Wikipedia does not aspire to report all niche uses. Avoid lists: try to group the various uses by similarity into a coherent paragraph. If the application stands alone, the application is either significant enough to merit a paragraph to itself, or insignificant enough not to deserve mention.

If reactions are to be described, emphasize the well established reactions (e.g. those in Organic and Inorganic Syntheses). Highly specialized reactions that are neither broadly applicable nor illustrative are inappropriate.

This paragraph, which is optional, should include the discovery/first synthesis of this compound. Past industrial processes can be described as well. If the etymology of the compound is complicated, it can be included here as well, instead of in the lede.

Wikipedia is not a buyer's guide. Do not include suppliers' information as they are spam magnets. Such lists are unmaintainable and cause problems. If, however, a particular compound is produced by only one or two suppliers, the suppliers names might be relevant.

The "See also" section should include concepts - do not use this section to list similar chemical compounds. Use the ((Chembox Related)) module in ((Chembox)) for this purpose.