Pa91 – Protactinium
- Atomic Number: 91
- Atomic Symbol: Pa
- Atomic Name: Protactinium
- Atomic Mass: 231.03588
- CPK Hex Color: 00A1FF
- Electron Configuration: [Rn]7s2 5f2 6d1
- Electron Negativity: 1.5
- Atomic Radius: 243
- Ionization Energy: 5.89
- Electron Affinity:
- Oxidation States: +5, +4
- Standard State: Solid
- Melting Point: 1845
- Boiling Point:
- Density: 15.37
- Group Block: Actinide
- Year Discovered: 1913
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