Element 59
Praseodymium (Pr)
Praseodymium (Pr) is element 59 of the periodic table, a lanthanide in period 6 (f-block) with an atomic mass of 140.91 and is a solid at standard conditions.
At a glance
- Atomic number
- 59
- Symbol
- Pr
- Atomic mass
- 140.91 u
- Category
- Lanthanides
- Period
- 6
- Block
- f-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f3 5s2 5p6 6s2
- Shorthand configuration
- [Xe] 4f3 6s2
- Electrons per shell
- 2, 8, 18, 21, 8, 2
- Oxidation states
- +2, +3, +4, +5
Physical properties
- Melting point
- 1208 K
- Boiling point
- 3793 K
- Density
- 6.773 g/cm3
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 1.13
- Atomic radius
- 247 pm
- Covalent radius
- 203 pm
- First ionization energy
- 527 kJ/mol
- Electron affinity
- 50 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Pr-141 | 140.90766 | 100% | Stable |
Common uses
- Magnets
- Lasers
- Arc lighting
- Colorant for glass
Discovery
- Year
- 1885
- Discovered by
- Carl Auer von Welsbach
- Country
- Austria