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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 average household size was 2.39 and the average family size was 2.92. In the city, the population was spread out, with 20.6% under the age of 18, 12.1% from 18 to 24, 35.0% from 25 to 44, 20.9% from 45 to 64, and 11.4% who were 65 years of age or older. The median age was 35 years.
Marguerite Catherine Perey (19 October 1909 – 13 May 1975) was a French physicist and a student of Marie Curie. In 1939, Perey discovered the element francium by purifying samples of lanthanum that contained actinium. In 1962, she was the first woman to be elected to the French Académie des Sciences, an honor denied to her mentor Curie.
December 3, 2014. The Saint Louis Downtown Historic District is a commercial historic district located on North Mill Street, West Saginaw Avenue, and West Center Avenue in Saint Louis, Michigan It was listed on the National Register of Historic Places in 2014. [ 1 ] The district is surrounded by residential neighborhoods, and is still the ...
Actinium-227 is the most stable isotope of actinium, with a half-life of 21.772 years. It mainly (98.62%) undergos beta decay, but sometimes (1.38%) it will undergo alpha decay instead. [1] 227 Ac is a member of the actinium series. It is found only in traces in uranium ores – one tonne of uranium in ore contains about 0.2 milligrams of 227 Ac.
Graphs of abundance vs atomic number. [] Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number; [ 5 ] siderophiles shown in yellow. Graphs of abundance against atomic number can reveal patterns relating abundance to stellar nucleosynthesis and geochemistry.
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.
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 ...