69 Tm Thulium 168.93
Lanthanide
Thulium 铥
[Xe] 4f¹³ 6s²
- Period 6
- Group —
- Block f
- Solid
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹³ 5s² 5p⁶ 6s²
Orbital diagram (valence)
- Electrons per shell
- 2, 8, 18, 31, 8, 2
- Unpaired electrons
- 1
- Zeff (Slater)
- 2.85
Properties
- Atomic weight
- 168.93
- Electronegativity (Pauling)
- 1.25
- First ionization energy
- 596.7 kJ/mol
- Electron affinity
- no data
- Covalent radius
- 190 pm
- van der Waals radius
- 227 pm
- Melting point
- 1818 K
- Boiling point
- 2223 K
- Density
- 9.32 g/cm³
- Melting / boiling point
- 1544.8 °C / 1949.8 °C
- Common oxidation states
- +3
- Discovered
- 1879
Periodic trend
Data: PubChem periodic table (public domain); atomic weights are IUPAC abridged standard values; covalent radii from Cordero et al. (2008).