CACrown ArchivesThe cinema collection
Menu
Research dossier · General Reference

Isotopes of samarium

Open-knowledge reference entry

Cross-disciplinary reference desk with index cards, atlas, dictionary and catalogue
General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionSep 17, 2026
Entity authoritySource title only
Source-derived summary

Naturally occurring samarium (62Sm) is composed of five stable isotopes, 144Sm, 149Sm, 150Sm, 152Sm and 154Sm, and two extremely long-lived radioisotopes, 147Sm and 148Sm, with 152Sm being the most abundant. 146Sm is also fairly long-lived, but is not long-lived enough to have survived in significant quantities from the formation of the Solar System on Earth, although it remains useful in radiometric dating in the Solar System as an extinct radionuclide. It is the longest-lived nuclide that has not yet been confirmed to be primordial. Its instability is due to having 84 neutrons, and so it may emit an alpha particle to form neodymium-142 with 82 neutrons.

Editorial summary

“Isotopes of samarium” enters the record as open-knowledge reference entry. Crown Archives preserves that source wording while asking what Isotopes, samarium and Open-knowledge can confirm, complicate or overturn.

Editorial reviewA concise reference frame for defining the subject, testing terminology and identifying the institution closest to the evidence. The current 106-word lead offers orientation but no explicit four-digit date, so chronology should not be assumed. The selected authority fields contribute no independent date. Its strongest next move is a source search built around Isotopes, samarium and Open-knowledge.
Editorial analysis

Why this record matters

“Isotopes of samarium” is worth following because a concise public description often conceals a longer documentary argument. Here, Isotopes, samarium and Open-knowledge provides the most credible route into that argument.

Evidence profile

Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Sep 17, 2026.

Critical limits

Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.

How to read it

Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.

Best used for
  • Subject orientation
  • Search vocabulary
  • Locating named sources
Verify next

The closest primary source, responsible institution and strongest cited specialist reference.

Three-step research path

  1. Establish the record: confirm the title “Isotopes of samarium”, its source revision and the description used here.
  2. Expand the search: follow Isotopes of samarium primary sources, Isotopes of samarium archive and Isotopes research across catalogues and specialist indexes.
  3. Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.

Questions for further research

  1. Which source most directly establishes the central claim about “Isotopes of samarium”?
  2. Which institution is responsible for the underlying evidence?
  3. What terminology or title could unlock a more precise catalogue search?
Subject index

Search terms from this dossier

Source & attribution

This entry incorporates text from Isotopes of samarium” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.