91Pa
Protactinium
Actinide
Properties of Protactinium
- Atomic number (Z)
- 91
- Symbol
- Pa
- Name
- Protactinium
- Atomic mass
- 231.036 u
- Period
- 7
- Group
- —
- Family
- Actinides (f-block)
- Classification
- Actinide
- Electron configuration
- [Rn] 5f² 6d¹ 7s²
About Protactinium
Protactinium is a chemical element with symbol Pa and atomic number 91 (atomic mass of about 231.036 u). It is classified as a actinide on the periodic table.
On the periodic table, Protactinium is located in period 7, outside the numbered groups (f-block), belonging to the actinides (f-block) family. An element's position reveals trends in its properties, such as atomic radius, electronegativity and metallic character.
The electron configuration of Protactinium is [Rn] 5f² 6d¹ 7s², which determines how it forms chemical bonds and takes part in reactions.