59Pr140.91
Praseodymium (Pr)
Element 59 · Lanthanide
Praseodymium (Pr) is a chemical element with atomic number 59. It is classified as a lanthanide in period 6 of the periodic table (the f-block). Its standard atomic weight is 140.91 u and its ground-state electron configuration is [Xe] 4f³ 6s².
Praseodymium facts
| Atomic number (Z) | 59 |
|---|---|
| Symbol | Pr |
| Standard atomic weight | 140.91 u |
| Category | Lanthanide |
| Group | — (f-block) |
| Period | 6 |
| Block | f-block |
| Electron configuration | [Xe] 4f³ 6s² |
| Electronegativity (Pauling) | 1.13 |
| State at 20 °C | Solid |
| Protons / electrons | 59 / 59 |
| Neutrons (most common isotope, approx.) | 82 |
| Molar mass | 140.91 g/mol |