61Pm
Promethium
Lanthanide
Properties of Promethium
- Atomic number (Z)
- 61
- Symbol
- Pm
- Name
- Promethium
- Atomic mass
- 145 u
- Period
- 6
- Group
- —
- Family
- Lanthanides (f-block)
- Classification
- Lanthanide
- Electron configuration
- [Xe] 4f⁵ 6s²
About Promethium
Promethium is a chemical element with symbol Pm and atomic number 61 (atomic mass of about 145 u). It is classified as a lanthanide on the periodic table.
On the periodic table, Promethium is located in period 6, outside the numbered groups (f-block), belonging to the lanthanides (f-block) family. An element's position reveals trends in its properties, such as atomic radius, electronegativity and metallic character.
The electron configuration of Promethium is [Xe] 4f⁵ 6s², which determines how it forms chemical bonds and takes part in reactions.