Actinium(III) oxide is a

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

containing the rare radioactive element

actinium Actinium is a chemical element with the symbol Ac and atomic number 89. It was first isolated by Friedrich Oskar Giesel in 1902, who gave it the name ''emanium''; the element got its name by being wrongly identified with a substance And ...

. It has the formula Ac₂O₃. It is similar to its corresponding

lanthanum Lanthanum is a chemical element with the symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air. It is the eponym of the lanthanide series, a group of 15 similar elements between lantha ...

compound,

lanthanum(III) oxide Lanthanum(III) oxide, also known as lanthana, chemical formula , is an inorganic compound containing the rare earth element lanthanum and oxygen. It is used in some ferroelectric materials, as a component of optical materials, and is a feedsto ...

, and contains actinium in the

oxidation state In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...

+3.Actinium

Great Soviet Encyclopedia The ''Great Soviet Encyclopedia'' (GSE; ) is one of the largest Russian-language encyclopedias, published in the Soviet Union from 1926 to 1990. After 2002, the encyclopedia's data was partially included into the later ''Bolshaya rossiyskaya e ...

(in Russian) Actinium oxide is not to be confused with Ac₂O (

acetic anhydride Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula (CH3CO)2O. Commonly abbreviated Ac2O, it is the simplest isolable anhydride of a carboxylic acid and is widely used as a reagent in organic synthesis. It is a col ...

), where Ac is an abbreviation for acetyl instead of the symbol of the element actinium.

Reactions

* Ac₂O₃ + 6HF → 2AcF₃ + 3H₂O * Ac₂O₃ + 6HCl → 2AcCl₃ + 3H₂O * 4Ac(NO₃)₃ → 2Ac₂O₃ + 12NO₂ + 3O₂ * 4Ac + 3O₂ → 2Ac₂O₃ * Ac₂O₃ + 2AlBr₃ → 2AcBr₃ + Al₂O₃ * 2Ac(OH)₃ → Ac₂O₃ + 3H₂O * Ac₂(C₂O₄)₃ → Ac₂O₃ + 3CO₂ + 3CO * Ac₂O₃ + 3H₂S → Ac₂S₃ + 3H₂O

References

Actinium compounds Sesquioxides {{inorganic-compound-stub