Uranium oxide

Uranium oxide is an oxide of the element uranium.

The metal uranium forms several oxides:
 * Uranium dioxide or uranium(IV) oxide (UO2, the mineral uraninite or pitchblende)
 * Diuranium pentoxide or uranium(V) oxide (U2O5)
 * Uranium trioxide or uranium(VI) oxide (UO3)
 * Triuranium octoxide (U3O8), the most stable uranium oxide; yellowcake typically contains 70 to 90 percent triuranium octoxide)
 * Uranyl peroxide (UO2O2 or UO4)
 * Amorphous uranium(VI) oxide (Am-U2O7)

Uranium dioxide is oxidized in contact with oxygen to form triuranium octoxide.


 * 3 UO2 + O2 →  U3O8; at 700 °C (970 K)

Preparation 38
During World War II, "Preparation 38" was the codename for uranium oxide used by German scientists.