59 · Pr
Praseodymium
Separated from didymium by von Welsbach in 1885.
Identity
- Atomic number
- 59
- Symbol
- Pr
- Canonical name
- Praseodymium
- Category
- lanthanide
- Group
- unassigned
- Period
- 6
- Block
- f
Series set apart from the main table. Whether group 3 is lanthanum or lutetium (actinium or lawrencium) is still discussed, so the group is left empty.
Properties
These quantities come from the Periodic Table JSON compilation. They have not yet been checked, one by one, against CIAAW atomic weights or NIST measurements. A value marked estimated is not a measurement.
- Atomic mass
- 140.907662 u
- Electron configuration
- [Xe] 4f3 6s2
- Electrons per shell
- 2, 8, 18, 21, 8, 2
- Standard state
- solid
- Density
- 6.77 g/cm³
- Melting point
- 1,208 K
- Boiling point
- 3,403 K
- Electronegativity
- 1.13 Pauling
- First ionization energy
- 527 kJ/mol
- Electron affinity
- 93 kJ/mol
Notable isotopes
This summary is not an inventory of every isotope.
- Pr-141 · 100 % · stable
History
Didymium split
Discovery · confirmed · 1885
Von Welsbach separates praseodymium from didymium, together with neodymium.
Etymology
- Theme
- color
- Language
- grec
- Root
- prasios + didymos
- Meaning
- leek-green, the green twin
Scientists
See also
Sources
- IUPAC, Periodic Table of the Elements
- Bowserinator, Periodic Table JSON. Compilation secondaire d’où viennent les grandeurs physiques importées (masse, densité, températures, énergies). Elles ne sont pas revérifiées une à une auprès du NIST ou de la CIAAW.
- John Emsley, Nature’s Building Blocks: An A–Z Guide to the Elements