Lutetium
Definition and meaning of Lutetium in chemistry.
Lutetium is a chemical element with the symbol Lu and atomic number 71. It is a dense, silvery-white metal that marks the final element in the lanthanide series and is characterized by extreme hardness.
In more detail
Lutetium stands out as the hardest and densest of all the lanthanides, possessing a noticeably higher melting point and boiling point relative to its immediate periodic table neighbors. It is never found as a free element in nature, but instead must be extracted from complex rare earth phosphate minerals like monazite and xenotime in minute, trace quantities. Chemically, the solid metal strongly resists oxidation in completely dry air, but it will slowly tarnish in moist air environments and readily dissolves in most weak aqueous acids. Situated at the very end of the f-block on the periodic table, lutetium possesses a completely filled f-orbital, forcing the element to be strictly trivalent (+3) in all of its stable chemical compounds. Due to its extreme scarcity in the Earth's crust and the immense difficulty involved in separating it from chemically similar rare earths, lutetium remains one of the most expensive metallic elements and has very few large-scale commercial applications.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Lu |
| Atomic number | 71 |
| Atomic mass | 174.97 u |
| Category | Lanthanide |
| State at room temperature | Solid |
| Melting point | 1652 °C |
| Discovered by | Georges Urbain, Carl Auer von Welsbach, and Charles James |
| Discovery year | 1907 |
Lutetium-177 is increasingly utilized in advanced targeted radionuclide therapies to selectively deliver destructive beta radiation to certain types of severe neuroendocrine tumors and progressive prostate cancers.
Frequently asked questions
Why is lutetium among the most expensive elements to purchase?
The high cost stems from its exceptionally low natural abundance combined with the complex, energy-intensive chemical separation processes required to isolate it from other similar rare earth metals.
Where does the elemental name lutetium originate?
The name is derived from Lutetia, which was the ancient Roman name for the settlement that eventually became the modern city of Paris, France.