Americium(III) oxide
Chemical compound
From Wikipedia, the free encyclopedia
Americium(III) oxide or americium sesquioxide is an oxide of the element americium. It has the empirical formula Am2O3. Since all isotopes of americium are only artificially produced, americium (III) oxide has no natural occurrence. The colour depends on the crystal structure, of which there are more than one. It is soluble in acids.[2]
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| Names | |
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| Other names
Americium sesquioxide | |
| Identifiers | |
3D model (JSmol) |
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| Properties | |
| Am2O3 | |
| Molar mass | 534 g·mol−1 |
| Density | 11.77 |
| Melting point | 2,205 °C (4,001 °F; 2,478 K) |
| Structure | |
| Trigonal, hP5 | |
| P3m1, No. 164 | |
| Related compounds | |
Other cations |
Curium(III) oxide |
Related compounds |
Americium dioxide Americium(II) oxide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Formation
Americium(III) oxide can be made by heating americium dioxide in hydrogen at 600°C.[3]
- 2 AmO2 + H2 → Am2O3 + H2O
Forms
The hexagonal form is coloured tan, and the cubic form is coloured red-brown the same as persimmon.[3] The cubic form converts to the hexagonal form on heating to 800°C.[3] The cubic form is non-stoichiometric with variable oxygen composition. It darkens with increasing oxygen.[3]