Element 71
Lutetium (Lu)
Lutetium (Lu) is element 71 of the periodic table, a lanthanide in period 6 (d-block) with an atomic mass of 174.97 and is a solid at standard conditions.
At a glance
- Atomic number
- 71
- Symbol
- Lu
- Atomic mass
- 174.97 u
- Category
- Lanthanides
- Period
- 6
- Block
- d-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d1 6s2
- Shorthand configuration
- [Xe] 4f14 5d1 6s2
- Electrons per shell
- 2, 8, 18, 32, 9, 2
- Oxidation states
- +3
Physical properties
- Melting point
- 1925 K
- Boiling point
- 3675 K
- Density
- 9.84 g/cm3
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 1.27
- Atomic radius
- 217 pm
- Covalent radius
- 187 pm
- First ionization energy
- 524 kJ/mol
- Electron affinity
- 50 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Lu-175 | 174.94078 | 97.41% | Stable |
Common uses
- PET scanners
- Catalysts
- LED light bulbs
- Dating meteorites
Discovery
- Year
- 1907
- Discovered by
- Georges Urbain, Carl Auer von Welsbach
- Country
- France/Austria