The Periodic Table of Elements
91
Pa
Protactinium
231.03588(2) amu
Additional Information:
| State | Group Block | Density | Atomic Radius | Electron Affinity | Ionization Energy | Melting Point | Boiling Point | Year Discovered |
|---|---|---|---|---|---|---|---|---|
| solid | actinoid | 15.37 kg/L | pm | 568 kJ/mol | 1845 °K | 4273 °K | 1913 |
