Pa91 – Protactinium
- Atomic Number91
- Atomic SymbolPa
- Atomic NameProtactinium
- Atomic Mass231.03588
- CPK Hex Color00A1FF
- Electron Configuration[Rn]7s2 5f2 6d1
- Electron Negativity1.5
- Atomic Radius243
- Ionization Energy5.89
- Electron Affinity
- Oxidation States+5, +4
- Standard StateSolid
- Melting Point1845
- Boiling Point
- Density15.37
- Group BlockActinide
- Year Discovered1913
Periodic Table of Elements. (2022, December 23). In PubChem and the National Library of Medicine. https://pubchem.ncbi.nlm.nih.gov/periodic-table/#view=table