Lutetium

Lutetium,  ₇₁Lu

General properties
Name, symbol	Lutetium, Lu
Appearance	Silvery-white
Lutetium in the periodic table
- ↑ Lu ↓ Lr Ytterbium ← Lutetium → Hafnium
Atomic number	71
Standard atomic weight (Ar)	174.9668(1)
Group, block	, f-block
Period	period 6
Electron configuration	[Xe] 4f14 5d1 6s2
per shell	2, 8, 18, 32, 9, 2
Physical properties
Silvery-white
Phase	Solid
Melting point	1925 K ​(1652 °C, ​3006 °F)
Boiling point	3675 K ​(3402 °C, ​​6156 °F)
Density near r.t.	9.841 g/cm3
when liquid, at	9.3 g/cm3
Heat of fusion	22 kJ/mol
Heat of	414 kJ/mol
Molar heat capacity	26.86 J/(mol·K)
pressure
Atomic properties
Oxidation states	3, 2, 1 ​(a weakly basic oxide)
Electronegativity	Pauling scale: 1.27
energies	1st: 523.5 kJ/mol 2nd: 1340 kJ/mol 3rd: 2022.3 kJ/mol
Atomic radius	empirical: 174 pm
Covalent radius	187±8 pm
Miscellanea
Crystal structure	​Hexagonal close-packed (hcp)
Thermal expansion	9.9 µm/(m·K) (poly)
Thermal conductivity	16.4 W/(m·K)
Electrical resistivity	5.82·10-7 Ω·m (poly)
Magnetic ordering	Paramagnetic
Young's modulus	68.6 GPa
Shear modulus	27.2 GPa
Bulk modulus	47.6 GPa
Poisson ratio	0.261
Vickers hardness	755–1160 MPa
Brinell hardness	890–1300 MPa
CAS Registry Number	7439-94-3
History
Naming	After Lutetia, Latin for: Paris, in the Roman era
Discovery	Carl Auer von Welsbach and Georges Urbain (1906)
First isolation	Carl Auer von Welsbach (1906)
Named by	Georges Urbain (1906)

Lutetium is a chemical element with symbol Lu and atomic number 71. It is considered the first element of the 6th-period transition metals and the last element in the lanthanide series, and is traditionally counted among the rare earths.

Lutetium's position in the periodic table is not entirely agreed on. Some models put it in group 3, others at the end of the f block with lanthanum and actinium instead, while other types of tables only have scandium and yttrium, leaving lutetium in the f block.

Properties

Chemical

Like most lanthanides, lutetium resists oxidation in dry air, but will slowly react with water. Lutetium dissolves readily in both strong and weak acids, with the nitrate, sulfate and acetate salts being soluble in water, while the fluoride, carbonate, phosphate and oxalate salts are insoluble in water.

Physical

Lutetium is a silvery white metal. It has a meting point of 1652 °C and a boiling point of 3402 °C. Its density is 9.841 g/cm³.

Availability

Lutetium can be purchased from Metallium and eBay.

Preparation

Reducing lutetium salts, like lutetium(III) chloride with calcium metal will yield lutetium metal.

Projects

• Element collecting
• Make Lu compounds
• Make lutetium aluminium garnet
• Make lutetium tantalate

Handling

Safety

Lutetium reacts with water to release hydrogen, which is flammable.

Luthetium compounds are thought to be non-toxic. At least one compound, Motexafin lutetium has been studied in cancer treatment.

Storage

Luthetium should be kept in closed containers, away from moisture and acids.

Disposal

Since lutetium is expensive, it's best to try to recycle it.

References

Relevant Sciencemadness threads

• Why is lutetium in the f-block and lanthanum in the d-block?