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Actinium is a chemical element; it has 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 André-Louis Debierne found in 1899 and called actinium. The actinide series, a set of 15 elements between actinium ...
The actinide series is a group of chemical elements with atomic numbers ranging from 89 to 102, [note 1] including notable elements such as uranium and plutonium.The nuclides (or isotopes) thorium-232, uranium-235, and uranium-238 occur primordially, while trace quantities of actinium, protactinium, neptunium, and plutonium exist as a result of radioactive decay and (in the case of neptunium ...
Actinium compounds are compounds containing the element actinium (Ac). Due to actinium's intense radioactivity, only a limited number of actinium compounds are known. These include: AcF 3, AcCl 3, AcBr 3, AcOF, AcOCl, AcOBr, Ac 2 S 3, Ac 2 O 3, AcPO 4 and Ac (NO 3) 3. Except for AcPO 4, they are all similar to the corresponding lanthanum compounds.
There are 34 known isotopes, from 203 Ac to 236 Ac, and 7 isomers. Three isotopes are found in nature, 225 Ac, 227 Ac and 228 Ac, as intermediate decay products of, respectively, 237 Np, 235 U, and 232 Th. 228 Ac and 225 Ac are extremely rare, so almost all natural actinium is 227 Ac. The most stable isotopes are 227 Ac with a half-life of 21. ...
Residential central air systems are usually from 1 to 5 tons (3.5 to 18 kW) in capacity. [ citation needed ] The efficiency of air conditioners is often rated by the seasonal energy efficiency ratio (SEER), which is defined by the Air Conditioning, Heating and Refrigeration Institute in its 2008 standard AHRI 210/240, Performance Rating of ...
Some advantages of underground houses include resistance to severe weather, quiet living space, an unobtrusive presence in the surrounding landscape, and a nearly constant interior temperature due to the natural insulating properties of the surrounding earth. One appeal is the energy efficiency and environmental friendliness of underground ...
Actinium (III) oxide is a chemical compound containing the rare radioactive element actinium. It has the formula Ac 2 O 3. It is similar to its corresponding lanthanum compound, lanthanum (III) oxide, and contains actinium in the oxidation state +3. [2][3] Actinium oxide is not to be confused with Ac 2 O (acetic anhydride), where Ac is an ...
I. Isotopes of actinium. Categories: Chemical elements. Actinides. Hidden categories: Commons category link is on Wikidata. Wikipedia categories named after chemical elements.