Praseodymium (Pr) – element 59
Praseodymium is a chemical element with the symbol Pr and atomic number 59. It is a lanthanide in group 3 (lanthanides), period 6 of the periodic table (f-block), and is a solid at room temperature.
Praseodymium (Pr) has atomic number 59, atomic mass 140.91 u and electron configuration [Xe] 4f3 6s2.
Praseodymium facts
| Symbol | Pr |
|---|---|
| Atomic number | 59 |
| Atomic mass | 140.91 u (g/mol) |
| Category | lanthanide |
| Group | group 3 (lanthanides) |
| Period | 6 |
| Block | f-block |
| Phase at 20 °C | Solid |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f3 |
| Noble-gas notation | [Xe] 4f3 6s2 |
| Electrons per shell | 2, 8, 18, 21, 8, 2 |
Bohr model and shells
Praseodymium has 59 electrons in 6 shells: 2, 8, 18, 21, 8, 2. Full configuration and noble-gas notation are in the table; work out any element or ion with the electron configuration calculator.
Physical and atomic properties
| Melting point | 1208 K (934.9 °C) |
|---|---|
| Boiling point | 3403 K (3129.8 °C) |
| Density | 6.77 g/cm³ |
| Electronegativity (Pauling) | 1.13 |
| Electron affinity | 93 kJ/mol |
| Ionization energies | 527, 1020, 2086 kJ/mol (1st, 2nd, 3rd) |
| Molar heat capacity | 27.2 J/(mol·K) |
| Discovered by | Carl Auer von Welsbach |
Use the atomic mass in the molar mass calculator for any formula containing Pr.
Position in the periodic table
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Frequently asked questions
What is the atomic mass of praseodymium?
The atomic mass of praseodymium is 140.91 u, so one mole of praseodymium atoms weighs 140.91 g.
What is the electron configuration of praseodymium?
Praseodymium has 59 electrons: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f³, or [Xe] 4f³ 6s² in noble-gas notation. Electrons per shell: 2, 8, 18, 21, 8, 2.
Is praseodymium a metal?
Yes. Praseodymium is a lanthanide.
Where is praseodymium on the periodic table?
Praseodymium is in group 3 (lanthanides), period 6, in the f-block.
Data: Periodic-Table-JSON (CC BY-SA 3.0); standard atomic weights from IUPAC (abridged). Values in brackets are the mass number of the longest-lived isotope.