Discovery date : 1885
Discovered by: Carl Auer von Welsbach
Origin of the name: The name is derived from the Greek 'prasios didymos' meaning green twin.
Allotropes :
~>PRASEODYMIUM is a chemical element with symbol Pr and atomic number 59. It is the third member of the lanthanide series and is traditionally considered to be one of the rare-earth metals.
| FACT BOX | |||
| Group | Lanthanides | Melting point | 931°C, 1708°F, 1204 K |
| Period | 6 | Boiling point | 3520°C, 6368°F, 3793 K |
| Block | f | Density (g cm−3) | 6.77 |
| Atomic number | 59 | Relative atomic mass | 140.908 |
| State at 20°C | Solid | Key isotopes | 141Pr |
| Electron configuration | [Xe] 4f36s2 | CAS number | 7440-10-0 |
| ChemSpider ID | 22384 | ChemSpider is a free chemical structure database | |
Didymium was announced in 1841 by Carl Mosander. He separated if from cerium, along with lanthanum. Didymium was accepted as an element for more than 40 years but it was really a mixture of lanthanoid elements. Some chemists wondered whether didymium too might consist of more than one element, and their suspicions were confirmed when Bohuslav Brauner of Prague in 1882 showed that its atomic spectrum was not that of a pure metal. The Austrian chemist, Carl Auer von Welsbach took up the challenge and in June 1885 he succeeded in splitting didymium into its two components, neodymium and praseodymium, which he obtained as their oxides.
A pure sample of praseodymium metal itself was first produced in 1931.