Category:Chemical element isotope articles by quality

The article meets the featured article criteria:

A featured article exemplifies Wikipedia's very best work and is distinguished by professional standards of writing, presentation, and sourcing. In addition to meeting the policies regarding content for all Wikipedia articles, it has the following attributes.

1. It is:
   1. well-written: its prose is engaging and of a professional standard;
   2. comprehensive: it neglects no major facts or details and places the subject in context;
   3. well-researched: it is a thorough and representative survey of the relevant literature; claims are verifiable against high-quality reliable sources and are supported by inline citations where appropriate;
   4. neutral: it presents views fairly and without bias;
   5. stable: it is not subject to ongoing edit wars and its content does not change significantly from day to day, except in response to the featured article process; and
   6. compliant with Wikipedia's copyright policy and free of plagiarism or too-close paraphrasing.
2. It follows the style guidelines, including the provision of:
   1. a lead: a concise lead section that summarizes the topic and prepares the reader for the detail in the subsequent sections;
   2. appropriate structure: a substantial but not overwhelming system of hierarchical section headings; and
   3. consistent citations: where required by criterion 1c, consistently formatted inline citations using footnotes—see citing sources for suggestions on formatting references. Citation templates are not required.
3. Media. It has images and other media, where appropriate, with succinct captions and acceptable copyright status. Images follow the image use policy. Non-free images or media must satisfy the criteria for inclusion of non-free content and be labeled accordingly.
4. Length. It stays focused on the main topic without going into unnecessary detail and uses summary style where appropriate.

The article meets the A-Class criteria:

A

Provides a well-written, clear and complete description of the topic, as described in Wikipedia:Article development. It should be of a length suitable for the subject, appropriately structured, and be well referenced by a broad array of reliable sources. It should be well illustrated, with no copyright problems. Only minor style issues and other details need to be addressed before submission as a featured article candidate. See the A-Class assessment departments of some of the larger WikiProjects (e.g. WikiProject Military history).

The article meets the good article criteria:

A good article is:

1. Well-written:
   1. the prose is clear, concise, and understandable to an appropriately broad audience; spelling and grammar are correct; and
   2. it complies with the Manual of Style guidelines for lead sections, layout, words to watch, fiction, and list incorporation.
2. Verifiable with no original research:
   1. it contains a list of all references (sources of information), presented in accordance with the layout style guideline;
   2. reliable sources are cited inline. All content that could reasonably be challenged, except for plot summaries and that which summarizes cited content elsewhere in the article, must be cited no later than the end of the paragraph (or line if the content is not in prose);
   3. it contains no original research; and
   4. it contains no copyright violations or plagiarism.
3. Broad in its coverage:
   1. it addresses the main aspects of the topic; and
   2. it stays focused on the topic without going into unnecessary detail (see summary style).
4. Neutral: it represents viewpoints fairly and without editorial bias, giving due weight to each.
5. Stable: it does not change significantly from day to day because of an ongoing edit war or content dispute.
6. Illustrated, if possible, by media such as images, video, or audio:
   1. media are tagged with their copyright statuses, and valid non-free use rationales are provided for non-free content; and
   2. media are relevant to the topic, and have suitable captions.

The article meets the six B-Class criteria:

1. The article is suitably referenced, with inline citations. It has reliable sources, and any important or controversial material which is likely to be challenged is cited. Any format of inline citation is acceptable: the use of <ref> tags and citation templates such as {{cite web}} is optional.
2. The article reasonably covers the topic, and does not contain obvious omissions or inaccuracies. It contains a large proportion of the material necessary for an A-Class article, although some sections may need expansion, and some less important topics may be missing.
3. The article has a defined structure. Content should be organized into groups of related material, including a lead section and all the sections that can reasonably be included in an article of its kind.
4. The article is reasonably well-written. The prose contains no major grammatical errors and flows sensibly, but does not need to be of the standard of featured articles. The Manual of Style does not need to be followed rigorously.
5. The article contains supporting materials where appropriate. Illustrations are encouraged, though not required. Diagrams, an infobox etc. should be included where they are relevant and useful to the content.
6. The article presents its content in an appropriately understandable way. It is written with as broad an audience in mind as possible. The article should not assume unnecessary technical background and technical terms should be explained or avoided where possible.

The article is better developed in style, structure and quality than Start-Class, but fails one or more of the criteria for B-Class. It may have some gaps or missing elements; need editing for clarity, balance or flow; or contain policy violations such as bias or original research. Articles on fictional topics are likely to be marked as C-Class if they are written from an in-universe perspective.

The article has a usable amount of good content but is weak in many areas. Quality of the prose may be distinctly unencyclopedic, and MoS compliance non-existent; but the article should satisfy fundamental content policies such as notability and BLP, and provide sources to establish verifiability. No Start-Class article should be in any danger of being speedily deleted.

The article is either a very short article or a rough collection of information that will need much work to become a meaningful article. It is usually very short, but if the material is irrelevant or incomprehensible, an article of any length falls into this category.

The article meets the featured list criteria:

1. Prose. It features professional standards of writing.
2. Lead. It has an engaging lead that introduces the subject and defines the scope and inclusion criteria.
3. Comprehensiveness.
   • (a) It comprehensively covers the defined scope, providing at least all of the major items and, where practical, a complete set of items; where appropriate, it has annotations that provide useful and appropriate information about the items.
   • (b) statements are sourced where they appear, and they provide inline citations if they contain any of the four kinds of material absolutely required to have citations.
   • (c) In length and/or topic, it meets all of the requirements for stand-alone lists; does not violate the content-forking guideline, does not largely duplicate material from another article, and could not reasonably be included as part of a related article.
4. Structure. It is easy to navigate and includes, where helpful, section headings and table sort facilities.
5. Style. It complies with the Manual of Style and its supplementary pages.
   • (a) Visual appeal. It makes suitable use of text layout, formatting, tables, and colour; and a minimal proportion of items are redlinked.
   • (b) Media files. It has images and other media, if appropriate to the topic, that follow Wikipedia's usage policies, with succinct captions. Non-free images and other media satisfy the criteria for the inclusion of non-free content and are labeled accordingly.
   • (c) Accessibility. It uses proper formating to be accessible to all readers. Bulleted and unbulleted lists and tables are structured correctly. Visual media, if included, utilize alternative (alt) text.
6. Stability. It is not the subject of ongoing edit wars and its content does not change significantly from day to day, except in response to the featured list process.