promethium
Let an agent identify promethium and its properties, relay isotopes, production and uses from reference sources, relay radiation safety information, and distinguish it from neighbouring lanthanides.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent identify promethium and its properties, relay isotopes, production and uses from reference sources, relay radiation safety information, and distinguish it from neighbouring lanthanides.
A chemical element with symbol Pm and atomic number 61, a radioactive lanthanide with no stable isotopes, of which promethium-145 is the longest-lived at about 17.7 years and promethium-147 the most used; it occurs naturally only in trace amounts from uranium fission and is produced in reactors, and it has been used in luminous paint, nuclear batteries and thickness gauges.
What it is for: Nuclear batteries, luminous sources and research.
It can be relay properties and isotopes; explain production and uses; relay radiation safety information; distinguish from other lanthanides.
Distinguishing features
No stable isotopes
Only lanthanide absent from the crust
Produced in reactors
Named after Prometheus
What it looks like
A silvery metal, rarely seen in bulk; its salts glow faintly from radioactivity.
Physical character
atomic number: 61 Z
longest-lived isotope: Pm-145, about 17.7 years - half-life
melting point: about 1042 degrees C - estimated
density: about 7.26 g/cm3 - estimated
How it is recognised
Element 61, symbol Pm
Radioactive lanthanide with no stable isotopes
Neodymium and samarium are the stable neighbours
Related models
is a kind of - the series
is a kind of - no stable isotopes
is adjacent to - element 60
is adjacent to - element 62
In practice
Families and kinds
isotopes from promethium-126 to promethium-163, all radioactive
promethium-147 as the working isotope
promethium compounds such as the chloride and oxide
promethium in nuclear batteries and luminous paint
Identifiers
symbol Pm
CAS 7440-12-2
Standards and regulation
Radiation protection and radioactive source rules
Transport rules for radioactive material
Nuclear material licensing
Failure modes and hazards
Radiation exposure
Contamination
Legacy luminous products
Also called
+17
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.promethium
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Identify What promethium is.
Identity.
Properties
Properties.
Properties
Properties.
- What are the physical and chemical properties of promethium? definition
- Is the question about promethium or a neighbouring lanthanide? boundary
Isotopes
Isotopes.
Isotopes
Isotopes.
- Which isotopes exist, and which are longest-lived or useful? definition
- Which entry fits the specific isotope? action
Source Occurrence and production.
Supply.
Occurrence
Occurrence.
Occurrence
Occurrence.
- Why is promethium absent from the crust, and where does it occur in trace amounts? provenance
- Which entry fits nuclear fission? action
Production
Production.
Production
Production.
- How is promethium produced and separated, and who produces it, with sources? provenance
- Which sources are cited? provenance
Use Uses and safety.
Application.
Uses
Uses.
Uses
Uses.
- How has promethium been used in luminous paint, nuclear batteries and gauges? provenance
- Which entry fits betavoltaic device? action
Safety
Radiation safety.
Safety
Safety.
- What radiation hazards does promethium present, and what rules apply? provenance
- Is the user asking about a personal exposure, which needs a specialist? boundary
Context History.
Context.
Discovery
Discovery.
Discovery
Discovery.
- How was promethium predicted, sought and finally identified in 1945, and how was it named? provenance
- Which references are standard? provenance
Teach
Teaching.
Teach
Teaching.
- How is promethium used to teach nuclear stability and the lanthanides? provenance
- Which entry fits the periodic table? action
What the second pass must settle
- Should isotopes be separate entries?
- How should reference data be linked?
- The registry entry has merged aliases naming isotopes; should they be split off?