Make your own free website on


Information valid for Lu-175 unless otherwise noted

Basic Information

Symbol: Lu
Atomic Number: 71
Mass: 174.967
Melting Point: 1656.0 C
Boiling Point: 3315.0 C
Number of Protons/Electrons: 71
Number of Neutrons: 104
Classification: Rare Earth
Crystal Structure: Hexagonal
Density @ 293 K: 9.85 g/cm3
Color: silvery

Atomic Structure

[Bohr Model of Lutetium]
Number of Energy Levels: 6

  1. First Energy Level: 2
    Second Energy Level: 8
    Third Energy Level: 18
    Fourth Energy Level: 32
    Fifth Energy Level: 9
    Sixth Energy Level: 2


Isotope Half Life
Lu-172 6.7 days
Lu-172m 3.7 minutes
Lu-173 1.37 years
Lu-174 3.3 years
Lu-174m 142.0 days
Lu-175 Stable
Lu-176 3.6E10 years
Lu-177 6.68 days
Lu-177m 160.7 days


Date of Discovery: 1907
Discoverer: Georges Urbain
Name Origin: From Lutetia (ancient name of Paris)
Uses: No uses known
Obtained From: gadolinite, xenotime