Lu
174.970Lutetium
Lutesyum
Lutetium is the last lanthanide, with atomic number 71. It is important in LSO and LYSO PET detector crystals, lutetium-177 targeted radiotherapy, Lu-Hf geochronology and dense rare earth materials.
71
174.97 g/mol
[Xe] 4f¹⁴ 5d¹ 6s²
2 | 8 | 18 | 32 | 9 | 2
1.27
9.84 g/cm³
1651.8 °C
3401.8 °C
Georges Urbain
Lutetium was separated from ytterbium-rich material in 1907 by Georges Urbain and independently by Carl Auer von Welsbach. Its name comes from Lutetia, the Latin name for Paris, after a long naming dispute with cassiopeium.
Lutetium-175
Natural abundance: About 97.4%. Stable and dominant natural lutetium isotope.Lutetium-176
Natural abundance: About 2.6%. Half-life: About 3.73 x 10¹⁰ years. Long-lived beta-emitting isotope used in Lu-Hf geochronology.Lutetium-177
Half-life: About 6.65 days. Medical beta-emitting radioisotope used in targeted radiotherapy.Lu₂O₃
Lutetium(III) OxidePrecursor for lutetium scintillators, catalysts and research materials.Lu₂SiO₅:Ce
LSO ScintillatorFast, dense scintillation crystal used in PET detectors.Lu₁.₈Y₀.₂SiO₅:Ce
LYSO ScintillatorCommon PET detector crystal with high stopping power and fast light output.[¹⁷⁷Lu]Lu-PSMA-617
Lutetium-177 PSMATargeted radioligand therapy for PSMA-positive prostate cancer.- Lutetium-177 PSMA and DOTATATE radiopharmaceuticals for targeted cancer therapy
- LSO and LYSO scintillation crystals in PET medical imaging detectors
- Lu-Hf isotope dating for meteorites, ancient rocks and mantle processes
- Lutetium oxide catalysts and research materials
- Dense rare earth compounds for detector and optical materials
Lutetium has no known essential biological role. Lutetium-177 labeled compounds are used in targeted nuclear medicine because they can deliver beta radiation to selected tumor cells.
- Lutetium is often treated as the final lanthanide because its 4f shell is filled and a 5d electron is present.
- The small ionic radius of Lu³⁺ is a visible result of lanthanide contraction.
- Lutetium-based PET crystals contain natural Lu-176, which produces intrinsic background radiation in detectors.
- Lu-Hf dating is valuable because Lu-176 decays to Hf-176 over geologic time.
- Lutetium has atomic number 71 and symbol Lu.
- Its electron configuration is [Xe] 4f¹⁴ 5d¹ 6s².
- The common oxidation state is +3.
- Remember lutetium for Lu-177 therapy, LYSO/LSO PET crystals and Lu-Hf dating.
What is the atomic number of lutetium?
The atomic number of lutetium is 71.
What is the electron configuration of lutetium?
Lutetium has the electron configuration [Xe] 4f¹⁴ 5d¹ 6s².
What is lutetium used for?
Lutetium is used in Lu-177 radiotherapy, LSO and LYSO PET detector crystals, isotope dating and specialized catalysts.
What is lutetium-177 used for?
Lutetium-177 is a beta-emitting medical radioisotope used in targeted radioligand therapies such as Lu-177 PSMA and Lu-177 DOTATATE.
Why is lutetium used in PET detectors?
Lutetium silicate crystals such as LSO and LYSO are dense, fast scintillators that efficiently detect gamma rays in PET scanners.
Is lutetium a lanthanide?
Yes. Lutetium is commonly listed as the last lanthanide, although its placement is sometimes discussed because it has a filled 4f shell and a 5d electron.