Thulium has an atomic number of 69, meaning each atom contains 69 protons in its nucleus.
The standard atomic weight of thulium is 168.93 u (unified atomic mass units).
Thulium is classified as a lanthanide.
Thulium is a solid at 20 Β°C (68 Β°F).
The melting point of thulium is 1544.85 Β°C / 1818 K.
The boiling point of thulium is 1949.85 Β°C / 2223 K.
The density of thulium is 9.32 g/cmΒ³ (20Β°C).
Thulium has a Pauling electronegativity of 1.25.
The electron configuration of thulium is [Xe] 4f13 6s2.
Thulium commonly exhibits the following oxidation states: +2, +3.
Thulium was discovered in 1879 by Per Teodor Cleve.
Thulium is a stable element with no naturally occurring radioactive isotopes.
No known biological role.
Thulium is used for: Portable X-ray sources; Lasers; Research.