61 Pm
Lanthanide
Promethium
Radioactive; in luminous paints.
Properties of Promethium
- Atomic number (Z)
- 61
- Symbol
- Pm
- Atomic mass
- 145 g/mol
- Category
- Lanthanide
- Group
- 3
- Period
- 6
- Electron configuration
- [Xe] 4f⁵ 6s²
- Electronegativity (Pauling)
- 1.13
- Atomic radius
- 205 pm
- First ionization energy
- 540 kJ/mol
- Melting point
- 1315 K (1041.8 °C)
- Boiling point
- 3273 K (2999.8 °C)
- Density
- 7.26 g/cm³
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1945
Frequently asked questions
What is Promethium?
Promethium (Pm) is a lanthanide, element number 61 on the periodic table. Radioactive; in luminous paints.
What is the atomic number and atomic mass of Promethium?
Promethium has atomic number 61 and an atomic mass of about 145 g/mol.
What is the electron configuration of Promethium?
The electron configuration of Promethium is [Xe] 4f⁵ 6s².
Where is Promethium on the periodic table?
Promethium sits in group 3, period 6, and is classified as a lanthanide.