Atomic number 71
Lutetium
Lanthanide
In the real world
Quick facts
- Atomic mass
- 174.97
- Group
- –
- Period
- 6
- State (STP)
- solid
- Electronegativity
- 1.27
- Common ox. states
- +3
Properties
Electron configuration
[Xe] 4f¹⁴ 5d¹ 6s²
- Ionization energy
- 523.5 kJ/mol
- Electron affinity
- 50.0 kJ/mol
- Melting point
- 1925.00 K (1651.8 °C)
- Boiling point
- 3675.00 K (3401.8 °C)
How dangerous is it?
1/5 · Low risk
The last and densest lanthanide, a hard silvery metal used in PET-scan detectors and as a catalyst. Low in toxicity, with only its powder to watch.
- FlammableImmediate
Powdered lutetium can ignite in air, though the solid metal resists corrosion well. (as filings or powder, not the solid)
Keep filings away from flame; the solid metal is safe to handle.
How it bonds· family overview
Lutetium (Lu) is a lanthanide - a soft, silvery metal that almost always loses 3 electrons to form a +3 ion (Ln³⁺). Its 4f electrons sit deep below the valence shell, so chemistry across the lanthanide row is remarkably similar: oxide, fluoride, chloride salts, all in the +3 state.
