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Research draft

cerium

vr.tr.cerium · PHY.MAT

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.

Thing Registry Physical world and living systems

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 cerium and its properties, relay production, uses, isotopes and history from reference sources, relay safety information, and distinguish it from neighbouring lanthanides.

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 stable isotopes.

What it is for: Catalysts, glass polishing, alloys and pigments.

It can be relay properties and isotopes; explain production and uses; relay safety information; distinguish from other lanthanides.

Distinguishing features

Most abundant rare earth

Tetravalent chemistry

Pyrophoric alloys

Catalytic oxide

What it looks like

A soft, silvery metal that tarnishes quickly in air, with pale yellow oxide.

Physical character

atomic number: 58 Z

standard atomic weight: 140.116 u

melting point: 795 degrees C

density: 6.77 g/cm3

How it is recognised

Element 58, symbol Ce

Most abundant lanthanide, with a stable tetravalent state

Lanthanum and praseodymium are the neighbouring lanthanides

Related models

is a kind of - in registry terms

lanthanide

is a kind of - in registry terms

heavy metal

is used in - as ceria

catalytic converter

is adjacent to - element 57

lanthanum

In practice

Families and kinds

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

Identifiers

symbol Ce

CAS 7440-45-1

Standards and regulation

Chemical safety data sheets

Rare earth trade and export rules

Nanomaterial regulation for ceria nanoparticles

Failure modes and hazards

Pyrophoricity of fine metal and alloys

Supply concentration

Nanoparticle exposure questions under study

Also called

cerium-119cerium-120cerium-121cerium-122cerium-123cerium-124cerium-125cerium-126cerium-127cerium-128cerium-129cerium-130cerium-130mcerium-131cerium-131mcerium-132cerium-132mcerium-133cerium-133mcerium-134cerium-135cerium-135mcerium-136mcerium-137mcerium-138mcerium-139mcerium-140mcerium-145cerium-146cerium-147cerium-148cerium-149cerium-150cerium-151cerium-152cerium-153cerium-154cerium-155cerium-156cerium-157

+12

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.cerium

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 cerium is.

Identity.

Properties

Properties.

Properties

Properties.

  1. What are the physical and chemical properties of cerium, including its two oxidation states? definition
  2. Is the question about cerium or a neighbouring lanthanide? boundary

Isotopes

Isotopes.

Isotopes

Isotopes.

  1. Which isotopes exist, and which are stable? definition
  2. Which entry fits the specific isotope? action
Source Occurrence and production.

Supply.

Occurrence

Occurrence.

Occurrence

Occurrence.

  1. Where does cerium occur, and how is it separated from other rare earths? provenance
  2. Which entry fits rare earth mining? action

Supply

Supply.

Supply

Supply.

  1. Who produces cerium, and how does its abundance affect price, with sources? measurement
  2. Which sources are cited? provenance
Use Uses and safety.

Application.

Uses

Uses.

Uses

Uses.

  1. How is cerium used in catalysts, polishing, lighters, glass and pigments? provenance
  2. Which entry fits ceria? action

Safety

Safety.

Safety

Safety.

  1. What hazards does cerium present, and what is known about ceria nanoparticles? provenance
  2. Is the user asking about a personal exposure, which needs a clinician or poison centre? boundary
Context History.

Context.

Discovery

Discovery.

Discovery

Discovery.

  1. How was cerium discovered in 1803, and how was it named after the asteroid Ceres? provenance
  2. Which references are standard? provenance

Teach

Teaching.

Teach

Teaching.

  1. How is cerium used to teach lanthanide chemistry? provenance
  2. Which entry fits the periodic table? action

What the second pass must settle

  • 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?