thulium
Let an agent identify thulium and its properties, relay isotopes, occurrence and uses from reference sources, 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 thulium and its properties, relay isotopes, occurrence and uses from reference sources, and distinguish it from neighbouring lanthanides.
A chemical element with symbol Tm and atomic number 69, a silvery lanthanide metal and the second rarest of the rare earth elements; thulium occurs in monazite and other minerals, has one stable isotope, thulium-169, and is used in portable X-ray sources through its isotope thulium-170, in solid-state lasers and in some superconductors.
What it is for: Portable X-ray sources, lasers and research uses.
It can be relay properties and isotopes; explain occurrence and extraction; relay uses; distinguish from other lanthanides.
Distinguishing features
Second rarest lanthanide
Single stable isotope Tm-169
Tm-170 as X-ray source
Trivalent chemistry with blue-green luminescence
What it looks like
A soft, silvery-grey metal that tarnishes slowly in air.
Physical character
atomic number: 69 Z
standard atomic weight: 168.934 u
melting point: 1545 degrees C
density: 9.32 g/cm3
How it is recognised
Element 69, symbol Tm
Lanthanide with one stable isotope
Neighbouring erbium and ytterbium have similar chemistry
Related models
is a kind of - the series
is a kind of - in general terms
is adjacent to - element 68
is adjacent to - element 70
In practice
Families and kinds
thulium metal and alloys
thulium compounds such as the oxide and halides
isotopes from thulium-144 to thulium-183, with Tm-169 stable and Tm-170 and Tm-171 of practical use
thulium-doped laser and fibre materials
Identifiers
symbol Tm
CAS 7440-30-4
Standards and regulation
Radiation safety rules for thulium-170 sources
Rare earth trade and export controls
Chemical safety data sheets
Failure modes and hazards
Radiation from activated isotopes
Dust flammability of fine metal
Supply concentration in few countries
Also called
+24
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.thulium
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 thulium is.
Identity.
Properties
Properties.
Properties
Properties.
- What are the physical and chemical properties of thulium? definition
- Is the question about thulium or a neighbouring lanthanide? boundary
Isotopes
Isotopes.
Isotopes
Isotopes.
- Which isotopes exist, and which are stable or useful? definition
- Which entry fits the specific isotope? action
Source Occurrence and production.
Supply.
Occurrence
Occurrence.
Occurrence
Occurrence.
- Where does thulium occur, and how is it separated from other rare earths? provenance
- Which entry fits rare earth mining? action
Supply
Supply.
Supply
Supply.
- Who produces thulium, and how scarce is it, with sources? measurement
- Which sources are cited? provenance
Use Uses.
Application.
X-ray
X-ray sources.
Xray
Xray.
- How is thulium-170 used in portable X-ray sources, and what safety rules apply? provenance
- Which entry fits radiography? action
Lasers
Lasers and materials.
Lasers
Lasers.
- How is thulium used in lasers, fibres and superconductors? provenance
- Which references are standard? provenance
Context History.
Context.
Discovery
Discovery.
Discovery
Discovery.
- How was thulium discovered by Cleve in 1879, and how was it named? provenance
- Which entry fits the history of the rare earths? action
Teach
Teaching.
Teach
Teaching.
- How is thulium presented in teaching 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?