Uranium oxide is an

oxide An oxide () is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– (molecular) ion. with oxygen in the oxidation state of −2. Most of the E ...

of the element

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...

. The metal uranium forms several oxides: *

Uranium dioxide Uranium dioxide or uranium(IV) oxide (), 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 rea ...

or uranium(IV) oxide (UO₂, the mineral

uraninite Uraninite, formerly pitchblende, is a radioactive, uranium-rich mineral and ore with a chemical composition that is largely UO2 but because of oxidation typically contains variable proportions of U3O8. Radioactive decay of the uranium causes t ...

or pitchblende) *

Diuranium pentoxide Diuranium pentoxide (uranium(V) oxide) is an inorganic chemical compound of uranium and oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a hig ...

or uranium(V) oxide (U₂O₅) *

Uranium trioxide Uranium trioxide (UO3), also called uranyl oxide, uranium(VI) oxide, and uranic oxide, is the hexavalent oxide of uranium. The solid may be obtained by heating uranyl nitrate to 400 °C. Its most commonly encountered polymorph, γ-UO3, is a ...

or uranium(VI) oxide (UO₃) *

Triuranium octoxide Triuranium octoxide (U3O8) is a compound of uranium. It is present as an olive green to black, odorless solid. It is one of the more popular forms of yellowcake and is shipped between mills and refineries in this form. U3O8 has potential long-ter ...

(U₃O₈), the most stable uranium oxide;

yellowcake Yellowcake (also called urania) is a type of uranium concentrate powder obtained from leach solutions, in an intermediate step in the processing of uranium ores. It is a step in the processing of uranium after it has been mined but before f ...

typically contains 70 to 90 percent triuranium octoxide) *

Uranyl peroxide Uranyl peroxide or uranium peroxide hydrate (UO4·nH2O) is a pale-yellow, soluble peroxide of uranium. It is found to be present at one stage of the enriched uranium fuel cycle and in yellowcake prepared via the ''in situ'' leaching and resin ion e ...

(UO₂O₂ or UO₄) *

Amorphous uranium(VI) oxide Amorphous uranium(VI) oxide (''am''-U2O7) is an orange diuranyl compound, most commonly obtained from the thermal decomposition of uranyl peroxide tetrahydrate at temperatures between 150 and 500 °C. It exists at room temperature as a powde ...

(''Am''-U₂O₇) Uranium dioxide is

oxidized Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...

in contact with

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

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.

References

Oxides Uranium compounds {{inorganic-compound-stub