Protactinium(IV) oxide
| Names | |
|---|---|
| IUPAC name Protactinium(IV) oxide | |
| Identifiers | |
| 3D model (JSmol) | |
| CompTox Dashboard (EPA) | |
| 
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| 
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| Properties | |
| O2Pa | |
| Molar mass | 263.034 g·mol−1 | 
| Appearance | Black crystals | 
| Melting point | 2,927 °C (5,301 °F; 3,200 K) | 
| Structure | |
| Fluorite (cubic), cF12 | |
| Fm3m, No. 225 | |
| a = 544.6 pm | |
| Hazards | |
| NFPA 704 (fire diamond) | |
| Related compounds | |
| Other cations | Thorium(IV) oxide Uranium(IV) oxide | 
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references | |
Protactinium(IV) oxide is a chemical compound with the formula PaO2. The black oxide is formed by reducing Pa2O5 with hydrogen at 1 550 °C. Protactinium(IV) oxide does not dissolve in H2SO4, HNO3, or HCl solutions, but reacts with HF.: 195
As protactinium(IV) oxide, like other protactinium compounds, is radioactive, toxic and very rare, it has no known technological use.