Promethium (Pm) is a chemical element belonging to the category Inner transition metal (lanthanide), with atomic number 61 and atomic mass 145.0000 u. This sheet describes its fundamental properties, periodic position and physical characteristics.
Identity
- Name: Promethium
- Symbol: Pm
- Atomic number: 61
- Atomic mass: 145.0000 u
Position in the periodic table
- Group: 3
- Period: 6
- Category: Inner transition metal (Lanthanide)
Physico-chemical properties
- Standard state: Solid
- Melting point: Very high (around 1100°C)
- Density: Medium (approx. 7.2 g/cm³)
- Electron configuration: [Xe] 4f⁵ 6s²
Scientific description
Promethium is a chemical element with symbol Pm and atomic number 61. It belongs to the category of inner transition metals (lanthanides) and occupies group 3 and period 6. Its standard atomic mass is approximately 145.0000 u.