|
91
Pa
231.0359
Protactinium |
Appearance & Characteristics | Reactions |
Other Forms Radius | Conductivity | Abundance
General:
| Name: Protactinium | Symbol: Pa |
| Group: Rare Earth, Actinides | Atomic weight: 231.0359 |
| Density @ 293 K: 15.4 g/cm3 | Atomic volume: 15.0 cm3/mol |
| Group: Rare Earth, Actinides | Discovered: 1917 |
States
| State (s, l, g): solid | |
| Melting point: 1873.2 K | Boiling point: 4500 K |
| Heat of fusion: 12.30 kJ/mol | Heat of vaporization: ? |
Energies
| 1st ionization energy: 568 kJ/mole | |
| Electronegativity: 1.5 | 2nd ionization energy: kJ/mole |
| Electron affinity: kJ/mole | 3rd ionization energy: kJ/mole |
| Specific heat: 0.12 J/gK | Heat atomization: 527 kJ/mole atoms |
Oxidation & Electrons
| Shells: 2,8,18,32,20,9,2 | Electron configuration: [Rn] 5f2 6d1 7s2 |
| Minimum oxidation number: 0 | Maximum oxidation number: 5 |
| Min. common oxidation no.: 0 | Max. common oxidation no.: 5 |
Appearance & Characteristics
| Structure: fcc: face-centered cubic | Color: silvery |
| Uses: | Toxicity: |
| Hardness: mohs | Characteristics: Radioactive |
Reactions
| Reaction with air: | |
| Reaction with 6 M HCl: | Reaction with 6 M HCl: |
| Reaction with 15 M HNO3: | Reaction with 6 M NaOH: none |
Other Forms
| Number of isotopes: 1 | Hydride(s): PaH3 |
| Oxide(s): PaO PaO2 Pa2O5 | Chloride(s): PaCl4 PaCl5 |
Radius
| Ionic radius (2- ion): pm | Ionic radius (1- ion): pm |
| Atomic radius: 163 pm | Ionic radius (1+ ion): pm |
| Ionic radius (2+ ion): pm | Ionic radius (3+ ion): 118 pm |
Conductivity
| Thermal conductivity: J/m-sec-deg | |
| Electrical conductivity: 1/mohm-cm | Polarizability: 25.4 A^3 |
Abundance
| Source: Synthetic(U-235 decay) | |
| Rel. abund. solar system: log | Abundance earth's crust: -5.9 log |
| cost, pure: $/100g | cost, bulk: $/100g |
