The hardest, densest and most expensive of the lanthanides.
- Atomic number
- 71
- Atomic mass
- 174.967 u
- Phase
- Solid
- Electron configuration
- [Xe] 4f¹⁴ 5d¹ 6s²
- Melting point
- 1,925 K · 1,651.9 °C
- Boiling point
- 3,675 K · 3,401.9 °C
- Density
- 9.841 g/cm³
- Electronegativity
- 1.27
- Period / Group
- 6 / —
- Discovery year
- 1907