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71Lu174.97 u

Lutetium

lanthanide
Atomic Number
71
Atomic Mass
174.97 u
Period
6
Group
3

Quick Facts

PropertyValue
SymbolLu
Atomic Number71
Atomic Mass174.97 u
CategoryLanthanide
Period6
Group3
Blockd
Electron Configuration[Xe] 4f¹⁴ 5d¹ 6s²

History and Discovery

Discovered by: Georges Urbain and Carl Auer von Welsbach Year of Discovery: 1907 Location: Paris, France and Vienna, Austria

Etymology

Named after Lutetia, the Latin name for Paris.

Applications and Uses

  • PET scan imaging (lutetium-177)
  • Cancer treatment (targeted radiotherapy)
  • LED phosphors
  • High-refractive-index glass
  • Catalysts
  • Dating meteorites (Lu-Hf dating)

Interesting Facts

  1. Last and smallest of the lanthanides
  2. Most expensive naturally occurring rare earth
  3. Lu-177 is increasingly important in cancer treatment
  4. Named after ancient Paris
  5. Hardest and densest lanthanide