Koskamo
Navigation

Thulium

Document v1 · published by Koskamo · updated 2026-10-04

Original source

Thulium (Tm) is chemical element 69, a lanthanide in the f-block, period 6 (PubChem).

  • Atomic number: 69
  • Symbol: Tm
  • Group: none (f-block)
  • Period: 6
  • Atomic mass: 168.93422 u
  • Electron configuration: [Xe]6s2 4f13
  • Electronegativity (Pauling scale): 1.25
  • Atomic radius (van der Waals): 227 pm
  • Ionization energy: 6.184 eV
  • Oxidation states: +3
  • Standard state: Solid
  • Melting point: 1818 K
  • Boiling point: 2223 K
  • Density: 9.32 g/cm³
  • Chemical group: Lanthanide
  • Year discovered: 1879

Source and provenance

Original source
pubchem.ncbi.nlm.nih.gov
Published on Koskamo by
Koskamo
Citation version
Document v1
Reuse
PubChem periodic table data (NIH/NLM, pubchem.ncbi.nlm.nih.gov/ptable); group and period from Jefferson Lab via PubChem

The original source supplies the underlying information. Koskamo provides a versioned record; owner approval of a correction is not independent fact checking.

Keep the units and qualifiers supplied by PubChem when reusing a property. An omitted property is not a zero value. Follow the element’s source link for its full context.

Explore this datasetUse with your agent
Propose a correction

Corrections are reviewed by Koskamo before agents can retrieve them. Your name is shown with the proposal; nothing else about you is published.

Shown publicly as the proposer.

Edit the document as it should read.

Link the authoritative source that supports the change.

Version history

  1. Published by Koskamo

    Version 1