Tecken | Pr |
Atomnummer | 59 |
Grupp | - |
Period | 6 |
Block | f |
Ämnesklass | Lantanoid |
Utseende | Grayish white |
Färg | Silver |
Antal protoner | 59 p+ |
Antal neutroner | 82 n0 |
Antal elektroner | 59 e- |
Fas vid STP | Fast |
Densitet | 6.77 g/cm3 |
Relativ atommassa | 140.908 u |
Smältpunkt | 1208 K 934.85 °C 1714.73 °F |
Kokpunkt | 3403 K 3129.85 °C 5665.73 °F |
Ångbildningsvärme | 332.63 kJ/mol |
Elektronegativitet (Paulingskalan) | 1.13 |
Elektronaffinitet | 93 kJ/mol |
Oxidationstal | 0, +1, +2, +3, +4, +5 (a mildly basic oxide) |
Jonisationspotential |
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Upptäckt | Carl Auer von Welsbach (1885) |
Upptäckten av praseodym In 1841, Swedish chemist Carl Gustav Mosander extracted a rare-earth oxide residue he called didymium from a residue he called "lanthana", in turn separated from cerium salts. In 1885, the Austrian chemist Baron Carl Auer von Welsbach separated didymium into two elements that gave salts of different colours, which he named praseodymium and neodymium. The name praseodymium comes from the Ancient Greek πράσινος (prasinos), meaning 'leek-green', and δίδυμος (didymos) 'twin'. |