Isotopes of rubidium
Open-knowledge reference entry

Rubidium (37Rb) has 35 known isotopes, from 72Rb to 106Rb, with naturally occurring rubidium composed of two: stable 85Rb (72.2%) and radioactive 87Rb (27.8%). The primordial radionuclide 87Rb has a half-life of 4.97×1010 years, beta decaying to stable 87Sr. It is, as the element is, widespread on Earth as rubidium readily substitutes for potassium in all minerals. The decay of 87Rb has been used extensively in dating rocks; see rubidium–strontium dating for a more detailed discussion.
Other than 87Rb, the longest-lived radioisotopes are 83Rb with a half-life of 86.2 days, 84Rb with a half-life of 32.82 days, and 86Rb with a half-life of 18.645 days. All other radioisotopes have half-lives less than a day, most less than 20 minutes. Of the isomeric states the most stable is 82mRb at 6.472 hours.
The ground state of 82Rb has a much shorter half-life of 1.2575 minutes. It is used medically in some cardiac positron emission tomography scans to assess myocardial perfusion. It is synthesized through the longer-lived 82Sr, made in a cyclotron, though a generator.
“Isotopes of rubidium” enters the record as open-knowledge reference entry. Crown Archives preserves that source wording while asking what Isotopes, rubidium and Open-knowledge can confirm, complicate or overturn.
Why this record matters
“Isotopes of rubidium” is worth following because a concise public description often conceals a longer documentary argument. Here, Isotopes, rubidium and Open-knowledge provides the most credible route into that argument.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Apr 6, 2026. The linked authority identifier is Q1321050. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1010.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. 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.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Isotopes of rubidium”, its source revision and the description used here.
- Expand the search: follow Isotopes of rubidium primary sources, Isotopes of rubidium archive and Isotopes research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Isotopes of rubidium”?
- Which institution is responsible for the underlying evidence?
- What terminology or title could unlock a more precise catalogue search?
Search terms from this dossier
This entry incorporates text from “Isotopes of rubidium” 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.