69
Tm
Thulium
Lanthanide period 6 f-block discovered: 1879
As a chemical element
Properties of the atom — they do not depend on what substance it is part of.
- Atomic number
- 69
- Atomic mass
- 168.93422 a.m.u.
- Electron configuration
- [Xe]6s2 4f13
- Electronegativity
- 1.25 on the Pauling scale
- Atomic radius
- 227 pm
- Ionization energy
- 6.184 eV
- Oxidation states
- +3
As a simple substance
Properties of the substance these atoms form under ordinary conditions.
- State at 25 °C
- Solid
- Melting point
- 1818 K (1 544,85 °C)
- Boiling point
- 2223 K (1 949,85 °C)
- Density
- 9.32 g/cm³