cerium
Let an agent identify cerium and its properties, relay production, uses, isotopes and history from reference sources, relay safety information, and distinguish it from neighbouring lanthanides.
Bundle → Layer → Finding → Questions Filled
4 bundles · 8 layers · 8 findings · 16 questions
Identify What cerium is.
Properties
Properties.
Properties
Properties.
- What are the physical and chemical properties of cerium, including its two oxidation states? definition
- Is the question about cerium or a neighbouring lanthanide? boundary
Isotopes
Isotopes.
Isotopes
Isotopes.
- Which isotopes exist, and which are stable? definition
- Which entry fits the specific isotope? action
Source Occurrence and production.
Occurrence
Occurrence.
Occurrence
Occurrence.
- Where does cerium occur, and how is it separated from other rare earths? provenance
- Which entry fits rare earth mining? action
Supply
Supply.
Supply
Supply.
- Who produces cerium, and how does its abundance affect price, with sources? measurement
- Which sources are cited? provenance
Use Uses and safety.
Uses
Uses.
Uses
Uses.
- How is cerium used in catalysts, polishing, lighters, glass and pigments? provenance
- Which entry fits ceria? action
Safety
Safety.
Safety
Safety.
- What hazards does cerium present, and what is known about ceria nanoparticles? provenance
- Is the user asking about a personal exposure, which needs a clinician or poison centre? boundary
Context History.
Discovery
Discovery.
Discovery
Discovery.
- How was cerium discovered in 1803, and how was it named after the asteroid Ceres? provenance
- Which references are standard? provenance
Teach
Teaching.
Teach
Teaching.
- How is cerium used to teach lanthanide chemistry? 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
- cerium-119, cerium-120, cerium-121, cerium-122, cerium-123, cerium-124, cerium-125, cerium-126, cerium-127, cerium-128, cerium-129, cerium-130
What it is Filled
A chemical element with symbol Ce and atomic number 58, a soft, ductile, silvery lanthanide and the most abundant rare earth element, which oxidises readily and shows both trivalent and tetravalent chemistry; cerium is used in catalytic converters, glass polishing, lighter flints and self-cleaning ovens, is recovered from monazite and bastnasite, and has four naturally occurring isotopes, of which three are stable and cerium-142 is radioactive.
Why it exists Filled
Let an agent identify cerium and its properties, relay production, uses, isotopes and history from reference sources, relay safety information, and distinguish it from neighbouring lanthanides.
Distinguishing features Filled
- Most abundant rare earth
- Tetravalent chemistry
- Pyrophoric alloys
- Catalytic oxide
What robots and AI may and may not do Filled
Must not
- Grind, machine or store fine cerium metal or its alloys without the fire controls they require.
- Present uncertain health effects of cerium oxide nanoparticles as settled in either direction.
- Dispose of rare earth processing waste into water or soil.
- Hide the origin of rare earth supplies in reporting.
Only with a human decision
- Handling bulk fine cerium powder or alloys in a workplace.
May
- Describe cerium, its compounds and uses in catalysts, glass polishing and lighter flints.
- Report supply sources and certification where records exist.
Moral aspects Filled
- Rare earth mining and refining often leave radioactive and acid waste in the communities that host it.
- Supply concentration makes cerium a matter of trade policy and pressure.
Who is affected
- Workers handling fine metal
- Communities near rare earth processing
- Users of cerium products
Owners Filled
Steward
Nobody owns the element; mine operators, refiners and holders answer for the material.
Links to other meta-models Filled
parent
- Q105789 - registry parent class
- Q19569 - registry parent class
related
- lanthanide - in registry terms
- heavy metal - in registry terms
- catalytic converter - as ceria
- lanthanum - element 57
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.cerium
- Wikidata: Q1385 (https://www.wikidata.org/wiki/Q1385)
- symbol: Ce
- CAS: 7440-45-1
Direct properties required Filled
- atomic number: 58 Z
- standard atomic weight: 140.116 u
- melting point: 795 degrees C
- density: 6.77 g/cm3
Recognition required Filled
- Element 58, symbol Ce
- Most abundant lanthanide, with a stable tetravalent state
- Lanthanum and praseodymium are the neighbouring lanthanides
- A soft, silvery metal that tarnishes quickly in air, with pale yellow oxide.
Capabilities and actions required Filled
- relay properties and isotopes
- explain production and uses
- relay safety information
- distinguish from other lanthanides
Hazards and failure modes required Filled
- Pyrophoricity of fine metal and alloys
- Supply concentration
- Nanoparticle exposure questions under study
Standards and interfaces required Filled
- Chemical safety data sheets
- Rare earth trade and export rules
- Nanomaterial regulation for ceria nanoparticles
Context of use required Filled
- Catalysts, glass polishing, alloys and pigments.
- cerium metal and mischmetal
- cerium compounds such as ceria and cerium nitrate
- isotopes from cerium-119 to cerium-157, with four stable isotopes
- cerium in catalysts, polishing and pigments
Sources Filled
- Wikidata item Q1385: cerium - identity and sense of the item
- Wikipedia: Cerium - general description of the item
Open questions
- Should isotopes and ceria be separate entries?
- How should reference data be linked?
- The registry entry has merged aliases naming isotopes; should they be split off?
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q1385/spec.json