caesium
Let an agent explain caesium as an element and its properties and isotopes, describe its role in timekeeping and industry, relay radiological information on caesium-137 with reference to authorities, and decline handling or acquisition detail for radioactive sources.
Bundle → Layer → Finding → Questions Filled
4 bundles · 8 layers · 8 findings · 16 questions
Understand What caesium is.
Element
The element.
Element
Element.
- What are the properties, occurrence and chemistry of caesium? definition
- Is the request seeking handling or acquisition detail for radioactive sources, which must be declined? boundary
Isotopes
Isotopes.
Isotopes
Isotopes.
- What isotopes of caesium exist, and why are caesium-133 and caesium-137 important? definition
- Which entry fits radioisotopes? action
Use Uses.
Clocks
Atomic clocks.
Clocks
Clocks.
- How does the caesium-133 transition define the second, and how do caesium atomic clocks work? definition
- Which entry fits atomic clocks? action
Industry
Industrial uses.
Industry
Industry.
- How is caesium used in drilling fluids, photoelectric devices and research? provenance
- Which entry fits a specific application? action
Radiological Caesium-137 and safety.
Releases
Environmental releases.
Releases
Releases.
- How has caesium-137 been released in nuclear accidents and tests, and how does it behave in the environment, according to authorities? provenance
- Is a radiological emergency present now, requiring official instructions? boundary
Protection
Protection.
Protection
Protection.
- What do radiation protection authorities say about caesium-137 exposure and food safety? provenance
- Which entry fits radiation protection? action
Learn History and teaching.
History
History.
History
History.
- How was caesium discovered by spectroscopy, and how did it become the time standard? provenance
- Which references are standard? provenance
Teach
Teaching.
Teach
Teaching.
- How can caesium illustrate alkali metal chemistry and metrology safely? action
- Which misconceptions arise? provenance
Classifiers Filled
- Family
- Thing Registry
- Category
- Physical world and living systems
- Entry kind
- thing
- Plane
- PHY
- Domain
- PHY.MAT
- Other names and narrower kinds
- caesium-137, caesium-129, caesium-135, caesium-116m, caesium-117m, caesium-118m, caesium-119m, caesium-120m, caesium-121m, caesium-122m1, caesium-122m2, caesium-122m3
What it is Filled
The chemical element with atomic number fifty-five, a soft, gold-coloured alkali metal that melts near room temperature and reacts violently with water, with one stable isotope, caesium-133, whose hyperfine transition defines the second, and radioactive isotopes such as caesium-137, a fission product of concern in nuclear accidents and used in industrial and medical sources, and caesium-135; caesium is used in atomic clocks, drilling fluids, photoelectric cells and research, and is described here without handling or acquisition detail for radioactive sources.
Why it exists Filled
Let an agent explain caesium as an element and its properties and isotopes, describe its role in timekeeping and industry, relay radiological information on caesium-137 with reference to authorities, and decline handling or acquisition detail for radioactive sources.
Distinguishing features Filled
- Most reactive stable metal
- Atomic clock standard
- Caesium-137 fission product
- Low melting point
What robots and AI may and may not do Filled
Must not
- Give information on obtaining, extracting or handling radioactive caesium sources.
- Assist in using radioactive material to harm people or contaminate places.
- Advise on handling caesium metal outside a qualified laboratory.
- Downplay contamination risks after a radiation incident.
Only with a human decision
- Any request about possessing, moving or disposing of a radioactive source.
May
- Explain caesium's properties and its role in atomic clocks and the definition of the second.
- State that radioactive caesium sources are strictly regulated and point to radiation authorities.
Moral aspects Filled
- Lost caesium sources have caused deadly contamination in communities.
- Accurate information in radiation emergencies protects the public.
Who is affected
- The public
- Scrap and waste workers
- Emergency responders
Owners Filled
Steward
The licensed holder of a source; nuclear regulators control possession.
Master systems
- National registers of licensed radioactive sources
Links to other meta-models Filled
parent
- Q19557 - registry parent class
- Q208106 - registry parent class
- Q428766 - registry parent class
related
- alkali metal - category
- light metal - category
- polonium - another radioactive element entry
- nuclear fission - source of caesium-137
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.caesium
- Wikidata: Q1108 (https://www.wikidata.org/wiki/Q1108)
Direct properties required Filled
- Melting temperature: Approximately 28.4 degrees Celsius - This approximate value applies to pure elemental caesium near standard atmospheric pressure.
- Boiling temperature: Approximately 671 degrees Celsius - This approximate value applies to pure elemental caesium at standard atmospheric pressure.
- Mass density: Approximately 1.9 grams per cubic centimetre - This approximate value describes solid elemental caesium near room temperature.
Recognition required Filled
- Atomic number fifty-five
- Defines the second through caesium-133
- Rubidium and francium are neighbouring alkali metals
- A soft gold-coloured metal, liquid near room temperature.
Capabilities and actions required Filled
- explain the element and isotopes
- describe timekeeping and industrial uses
- relay radiological information
- decline source handling detail
Hazards and failure modes required Filled
- Providing handling or acquisition detail for radioactive sources, which must be declined
- Fire and explosion from reaction with water
- Contamination from caesium-137 releases
Standards and interfaces required Filled
- SI definition of the second
- Radiation protection and radioactive source control
- Chemical safety regulations for reactive metals
Context of use required Filled
- Element fifty-five, an alkali metal.
- caesium metal and compounds
- caesium-133 and the definition of the second
- caesium-137 and other radioisotopes
- caesium in drilling fluids and industry
- caesium in research and photoelectric devices
Sources Filled
- Wikidata item Q1108: caesium - identity and sense of the item
- Wikipedia: Caesium - general description of the item
Open questions
- Should caesium-137 be a separate entry?
- How should radiation authorities be linked?
- How should metrology resources be linked?
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q1108/spec.json