Lutetium is a dense lanthanide with specialized uses in research and catalysis. It occurs with other rare-earth elements in minerals such as monazite and is difficult to separate. Its place at the end of the lanthanide series offers a useful comparison with earlier members.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
How does a lutetium-containing scintillator make incoming gamma radiation detectable?
Cerium-doped lutetium oxyorthosilicate crystal
FOLLOW THIS RELATIONSHIP
Use a combined crystal material
The detector contains cerium-doped lutetium oxyorthosilicate. Lutetium belongs to the crystal host, while cerium contributes important luminescent behavior within the material.
Explore the model (optional)
LuFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
Which sequence preserves the detector’s mechanism?
Atomic identity, reference properties and structure models
INTERACTIVE 3D71 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Xe] 4f14 5d1 6s2. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
Lutetium was distinguished in 1907 during investigations of material previously called ytterbium. Georges Urbain published the identification, while Carl Auer von Welsbach and Charles James also carried out independent work on the same separation problem. Pure lutetium metal was obtained in 1953. The history is best understood as converging investigations of a stubborn mixture, rather than as a single person suddenly producing a pure new metal.
1907
Lutetium distinguished
Independent investigations separated lutetium from ytterbium material.
Lutetium occurs in small amounts within rare-earth such as monazite. It accompanies other elements that can be difficult to separate chemically. determines whether those atoms become a research specimen or part of a specialized compound, so geological presence and a usable material supply are distinct stages.
Lutetium commonly forms trivalent compounds, and its useful behavior depends on the resulting material. Lutetium-containing scintillator can help turn energetic radiation into detectable light. That function is not the same as ordinary visible reflection from metal, nor does it require treating every lutetium atom as a light source.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
solid
293.15 K, 101.325 kPa
Melting point in K
1925 K
at standard pressure unless noted
Boiling point in K
3675 K
101.325 kPa
Density in g/cm³
9.84 g/cm³
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
1.27 Pauling
Pauling scale
First ionization energy in kJ/mol
523.5 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
187 pm
single-bond covalent radius
Common oxidation states
+3
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust in mg/kg
0.8 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year in CE
1907 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 6
Lu 1.27 Pauling · Lutetium
Electronegativity across period 6. Exact values.
Cs
0.79
Ba
0.89
La
1.1
Ce
1.12
Pr
1.13
Nd
1.14
Sm
1.17
Eu
1.2
Gd
1.2
Tb
1.1
Dy
1.22
Ho
1.23
Er
1.24
Tm
1.25
Yb
1.1
Lu
1.27
Hf
1.3
Ta
1.5
W
2.36
Re
1.9
Os
2.2
Ir
2.2
Pt
2.28
Au
2.54
Hg
2
Tl
1.62
Pb
2.33
Bi
2.02
Po
2
At
2.2
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
