francium
Let an agent explain francium as an element, relay its properties, occurrence and research uses from reference sources, and separate fact from popular exaggeration about its reactivity and quantity.
Bundle → Layer → Finding → Questions Filled
4 bundles · 8 layers · 8 findings · 16 questions
Element What francium is.
Properties
Properties and isotopes.
Properties
Properties.
- What are the known and predicted properties of francium, and what isotopes exist? definition
- Is the question about the element or about popular claims that need correction? boundary
Occurrence
Occurrence and production.
Occurrence
Occurrence.
- How does francium occur naturally, and how is it produced for research? provenance
- Which entry fits actinium? action
Research Scientific use.
Experiments
Trapped atom experiments.
Experiments
Experiments.
- How is francium studied in atom traps, and what questions do experiments address? provenance
- Which references are standard? provenance
Limits
What cannot be done.
Limits
Limits.
- Why can francium not be studied in bulk, and what follows for claims about it? provenance
- Which entry fits radioactive decay? action
Safety Radiation.
Radiation
Radiation hazard.
Radiation
Radiation.
- What radiation protection rules apply to research with francium? provenance
- Which entry fits radiation protection? action
Handling
Handling.
Handling
Handling.
- How are trace amounts handled in laboratories? provenance
- Is the question about a specific facility, which needs its safety officer? boundary
Context History and teaching.
History
Discovery.
History
History.
- How did Marguerite Perey discover francium in 1939? provenance
- Which entry fits the discoverer? action
Teach
Teaching.
Teach
Teaching.
- How is francium presented in teaching, and which misconceptions arise? provenance
- Which entry fits the periodic table? action
Classifiers Filled
- Family
- Thing Registry
- Category
- Physical world and living systems
- Entry kind
- thing
- Plane
- PHY
- Domain
- PHY.MAT
- Other names and narrower kinds
- francium-199, francium-200, francium-200m, francium-201, francium-202, francium-202m, francium-203, francium-204, francium-204m1, francium-204m2, francium-205, francium-206
What it is Filled
A highly radioactive alkali metal, chemical element 87, the heaviest member of group 1 and one of the rarest naturally occurring elements, formed in trace amounts by decay of actinium; its longest-lived isotope, francium-223, has a half-life of about 22 minutes, so it has no practical uses beyond research in atomic physics and spectroscopy.
Why it exists Filled
Let an agent explain francium as an element, relay its properties, occurrence and research uses from reference sources, and separate fact from popular exaggeration about its reactivity and quantity.
Distinguishing features Filled
- Heaviest alkali metal
- No stable isotopes
- Trace natural occurrence in uranium ores
- Studied as trapped atoms
What robots and AI may and may not do Filled
Must not
- Present popular claims about francium's reactivity as observed fact.
- Help obtain or handle radioactive material outside licensing and radiation protection rules.
- Invent measured values for bulk francium.
- Present francium as a practical material for ordinary uses.
Only with a human decision
- Approving research with radioactive sources.
May
- Report francium's properties and isotopes from authoritative sources.
- Explain why bulk properties of francium have never been observed.
Moral aspects Filled
- Radioactive materials need strict control to protect researchers and the public.
Who is affected
- Researchers
- The public
Owners Filled
Steward
Nobody holds it in bulk; licensed laboratories answer for the traces they make.
Links to other meta-models Filled
parent
- Q19557 - registry parent class
- Q208106 - registry parent class
related
- alkali metal - group 1
- actinium - decay of actinium-227
- caesium - the lighter homologue
- atomic physics - trapped atom experiments
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.francium
- Wikidata: Q671 (https://www.wikidata.org/wiki/Q671)
- chemical symbol: Fr
- CAS number: 7440-73-5
Direct properties required Filled
- atomic number: 87
- half-life of francium-223: about 22 minutes - longest-lived isotope
- natural abundance: grams at any time in the crust estimate - often quoted as about 20-30 g
Recognition required Filled
- Element 87, alkali metal
- Extremely radioactive and short-lived
- Caesium is the heaviest stable alkali metal
- Never seen in bulk; expected to be a silvery metal, observed only as trapped atoms.
Capabilities and actions required Filled
- explain properties and isotopes
- explain occurrence and how it is made
- relay research uses
- correct common exaggerations
Hazards and failure modes required Filled
- Radiation hazard in research
- Popular claims about explosive reactivity that cannot be tested in bulk
- Confusing estimates of natural quantity
Standards and interfaces required Filled
- Radiation protection regulations for research handling
Context of use required Filled
- Not for anything practical; a subject of atomic research.
- francium-223 from actinium decay
- synthetic isotopes made in accelerators
- francium in atomic physics experiments
Sources Filled
- Wikidata item Q671: francium - identity and sense of the item
- Wikipedia: Francium - general description of the item
Open questions
- Should isotopes be separate entries?
- How should research references be linked?
- The registry entry has merged isotope aliases; should they be split off?
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q671/spec.json