69 Tm
Lanthanide
Thulium
Rarest natural lanthanide.
Properties of Thulium
- Atomic number (Z)
- 69
- Symbol
- Tm
- Atomic mass
- 168.93 g/mol
- Category
- Lanthanide
- Group
- 3
- Period
- 6
- Electron configuration
- [Xe] 4f¹³ 6s²
- Electronegativity (Pauling)
- 1.25
- Atomic radius
- 222 pm
- First ionization energy
- 597 kJ/mol
- Melting point
- 1818 K (1544.8 °C)
- Boiling point
- 2223 K (1949.8 °C)
- Density
- 9.321 g/cm³
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1879
Frequently asked questions
What is Thulium?
Thulium (Tm) is a lanthanide, element number 69 on the periodic table. Rarest natural lanthanide.
What is the atomic number and atomic mass of Thulium?
Thulium has atomic number 69 and an atomic mass of about 168.93 g/mol.
What is the electron configuration of Thulium?
The electron configuration of Thulium is [Xe] 4f¹³ 6s².
Where is Thulium on the periodic table?
Thulium sits in group 3, period 6, and is classified as a lanthanide.