Promethium (Pm) — Element 61: Properties & Data | Aladdin Scientific
Promethium(Pm) — Element 61
Promethium (Pm) is a lanthanide with atomic number 61 and atomic mass 144.913. It has melting point 1315 K (1042 °C), boiling point 3273 K (3000 °C), density 7.26 g/cm³. It sits in period 6 of the periodic table and was discovered in 1945.
Key facts
| Atomic mass | 144.9128 u |
|---|---|
| Electron configuration | [Xe]6s2 4f5 |
| Oxidation states | +3 |
| Atomic radius (van der Waals) | 236 pm |
| Ionization energy | 5.55 eV |
| Melting point | 1315 K |
| Boiling point | 3273 K |
| Density | 7.26 g/cm³ |
| Standard state | Solid |
| Year discovered | 1945 |
Frequently asked questions
What is the electron configuration of promethium?
The ground-state electron configuration of promethium is [Xe]6s2 4f5.
What group and period is promethium in?
Promethium (Pm) is in period 6 (lanthanide series) of the periodic table, classified as a lanthanide.
What is the melting point of promethium?
Promethium melts at 1315 K (1042 °C).
What is the standard state of promethium?
Promethium is a solid at standard temperature and pressure.
Related elements
About this data: property values compiled from IUPAC Standard Atomic Weights (2021), the NIST Atomic Spectra Database, and PubChem. Curated by the Aladdin Scientific technical team. Last reviewed: .