Lutetium is a dense, silvery-white rare earth metal. Here is a collection of interesting element facts for lutetium or cassiopeium:
- Lutetium was the last natural rare earth element that was discovered. It was discovered in 1907 by three scientists, working independently from each other. Georges Urbain, Charles James, and Carl Auer von Welsbach all extracted lutetium from a sample of the mineral ytterbia. Urbain is often credited for the discovery of the element because his results were published first.
- The element originally was named lutecium. In 1949, the name was officially changed to lutetium, in keeping with naming of other elements.
- Lutetium is the hardest lanthanide element.
- It’s also the most expensive lanthanide.
- Atoms of lutetium are the smallest of any lanthanide element.
- Lutetium metal is silvery-white, soft, malleable, and ductile.
- Lutetium is never found naturally in pure form. Sources of lutetium include nearly all minerals which contain the similar element, yttrium. A commercial source of lutetium is monazite, which consists of about 0.003 percent lutetium.
- Two naturally occurring isotopes of lutetium have been identified. Lutetium-175 is a stable isotope. The other natural isotope, lutetium-176, has a half-life of nearly 38 trillion years. 32 synthetic radioisotopes have been synthesized.
- Pure lutetium is obtained by reduction of anhydrous LuCl3 or LuF3 using an alkali metal or alkaline earth metal. Only about 10 tons of lutetium are produced globally each year.
- The primary use of lutetium is in the petroleum industry as a catalyst.
Lutetium Chemical and Physical Properties
Element Name: Lutetium (German Cassiopeium)
Atomic Number: 71
Atomic Weight: 174.967
Discovery: Georges Urbain 1907 (France)
Electron Configuration: [Xe] 4f14 5d1 6s2
Element Classification: Rare Earth (Lanthanide Series)
Word Origin: Named for the ancient name of Paris, Lutecia.
Density (g/cc): 9.8404
Melting Point (K): 1936
Boiling Point (K): 3668
Appearance: silvery-white, hard, dense metal
Atomic Radius (pm): 175
Atomic Volume (cc/mol): 17.8
Covalent Radius (pm): 156
Ionic Radius: 85 (+3e)
Specific Heat (@20°C J/g mol): 0.155
Evaporation Heat (kJ/mol): 414
Pauling Negativity Number: 1.27
First Ionizing Energy (kJ/mol): 513
Oxidation States: 3
Lattice Structure: Hexagonal
Lattice Constant (Å): 3.510
Lattice C/A Ratio: 1.585
References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange’s Handbook of Chemistry (1952), CRC Handbook of Chemistry & Physics (18th Ed.)