Uranium dioxide
| Names | |
|---|---|
| IUPAC names Uranium dioxide Uranium(IV) oxide | |
| Other names Urania Uranous oxide | |
| Identifiers | |
| 3D model (JSmol) | |
| ChemSpider | |
| ECHA InfoCard | 100.014.273 | 
| EC Number | 
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| PubChem CID | |
| RTECS number | 
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| UNII | |
| CompTox Dashboard (EPA) | |
| 
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| 
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| Properties | |
| UO2 | |
| Molar mass | 270.03 g/mol | 
| Appearance | black powder | 
| Density | 10.97 g/cm3 | 
| Melting point | 2,865 °C (5,189 °F; 3,138 K) | 
| insoluble | |
| Structure | |
| Fluorite (cubic), cF12 | |
| Fm3m, No. 225 | |
| a = 547.1 pm  | |
| Tetrahedral (O2−); cubic (UIV) | |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 78 J·mol−1·K−1 | 
| Std enthalpy of formation (ΔfH⦵298) | −1084 kJ·mol−1 | 
| Hazards | |
| GHS labelling: | |
| Danger | |
| H300, H330, H373, H410 | |
| P260, P264, P270, P271, P273, P284, P301+P310, P304+P340, P310, P314, P320, P321, P330, P391, P403+P233, P405, P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | N/A | 
| Safety data sheet (SDS) | ICSC 1251 | 
| Related compounds | |
| Other anions | Uranium(IV) sulfide Uranium(IV) selenide | 
| Other cations | Protactinium(IV) oxide Neptunium(IV) oxide | 
| Triuranium octoxide Uranium trioxide | |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references | |
Uranium dioxide or uranium(IV) oxide (UO2), also known as urania or uranous oxide, is an oxide of uranium, and is a black, radioactive, crystalline powder that naturally occurs in the mineral uraninite. It is used in nuclear fuel rods in nuclear reactors. A mixture of uranium and plutonium dioxides is used as MOX fuel. It has been used as an orange, yellow, green, and black color in ceramic glazes and glass.