Lutetium (Lu)
Lutetium (Lu) is element 71, a lanthanide. Atomic mass 174.96669, configuration [Xe] 4f¹⁴ 5d¹ 6s². Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 71 |
|---|---|
| Symbol | Lu |
| Standard atomic weight | 174.96669(5) |
| Category | Lanthanide |
| Period | 6 |
| State at room temperature | Solid |
| Electron configuration | [Xe] 4f¹⁴ 5d¹ 6s² |
| Valence electrons | 2 (Variable) |
| Common oxidation states | +3 |
| Common ions | No common ions |
| Electronegativity (Pauling) | 1 |
| First ionization energy | 524 kJ/mol |
| Electron affinity | 32.81 kJ/mol |
| Atomic radius | 175 pm |
| Density | 9.84 g/cm³ |
| Melting point | 1677°C |
| Boiling point | 3402°C |
| Specific heat | 0.154 J/(g·°C) |
Natural isotopes
- Lu-175: Stable
- Lu-176: Radioactive
Common uses
- PET scan detectors (LSO crystals)
- Cancer treatment
- Catalysts
Where it matters
- Cancer Therapy (Lu-177 radiotherapy)
- Petroleum cracking
Hazards
- Low toxicity
History
| Discovered | 1907 |
|---|---|
| Discovered by | Georges Urbain |
| Name | From Lutetia (Paris) |