Lu
Lutetium
Atomic number: 71Mass: 174.967 uCategory: Lanthanide
About Lutetium
Lutetium is a silvery-white metal. It is the last element in the lanthanide series. It is one of the rarest and most expensive of the rare earth metals. It has potential use in PET scan detectors.
Properties
Period
6
Group
N/A
Block
F
Category
Lanthanide
Electronegativity
1.27 (Pauling)
Ionization Energy
523.5 kJ/mol
Melting Point
1925 K (1652°C)
Boiling Point
3675 K (3402°C)
Density
9.841 g/cm³
Oxidation States
+3
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹ 6s²
[Xe] 4f¹⁴ 5d¹ 6s²
Shell 1:2e⁻
Shell 2:8e⁻
Shell 3:18e⁻
Shell 4:32e⁻
Shell 5:9e⁻
Shell 6:2e⁻
Real-World Uses
PET scan detectors
Cancer radiotherapy (Lu-177)
Refining petroleum
LED technology
X-ray phosphors
Fun Fact
Lutetium is named after Lutetia, the Roman name for Paris — and it's one of the most expensive metals, costing more than gold per gram!