PTL:Praseodymium
From ChemEd Collaborative
| Symbol: | Pr |
|---|---|
| Atomic Number: | 59 |
| Atomic Weight: | 140.90765(2) |
| Electron Configuration: | [Xe] 4f3 6s2 |
| Atomic Radius: | 182.5pm |
| Melting Point: | 931°C |
| Boiling Point: | 3520°C |
| Heat of Fusion: | 6.89kJ/mol |
| Heat of Vaporization: | 296.8kJ/mol |
| Specific Heat Capacity: | 0.19J/gK |
Praseodymium is a metal and a member of the lanthanide or rare earth elements, which stretches from lanthanum (La) through lutetium (Lu).
Contents |
Discovered
The isolation of the element was difficult, as was the case for most of the lanthanides. Their chemical similarity means that they are often found in the same mineral deposit and that they behave similarly when one tries to separate them. In 1841 Mosander separated a rare oxide that he called didymia from another mineral lanthana. In 1885 Auer separated didymia into two other oxides, praseodymia and neodymia, which in turn gave salts of different colors. Pure praseodymium metal was not isolated until 1931.
Name
The name of the element comes from the Greek words prasios (green) and didymos (twin).
Characteristics
Pr metal is silvery in appearance and is soft, malleable, and ductile. It does not corrode as readily as other lanthanides when exposed to air, but it should be protected as it will form a coating of green Pr2O3.
Uses
An alloy of various rare earth elements, misch metal, is about 5% praseodymium. The metal is used for making [lighter flints], among other things.
The glass in [welding masks] contains a mixture of Pr and Nd oxides, because these oxides filter out certain wavelengths of light. [Glass may be colored green] by Pr2O3, and some [photographic filters] and [ceramic tiles] may contain this oxide as well.
Praseodymium, alongside other rare earth metals, is used in carbon arc lighting in the motion picture industry.
Emission Spectra
This is the emission spectra for Praseodymium.
