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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.
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.
André-Louis Debierne (French pronunciation: [ɑ̃dʁe lwi dəbjɛʁn]; 14 July 1874 – 31 August 1949) was a French chemist.He is often considered the discoverer of the element actinium, though H. W. Kirby disputed this in 1971 and gave credit instead to German chemist Friedrich Oskar Giesel.
The Woodley Fire, which has set at least 30 acres ablaze, was discovered on Wednesday at 6:15 a.m. in the Sepulveda Basin, around 19 miles northwest of the City of Los Angeles, according to Cal ...
Hahn pursued a report by Stefan Meyer and Egon Schweidler of a decay product of actinium with a half-life of about 11.8 days. Hahn determined that it was actinium X . He also discovered that at the moment when a radioactinium (thorium-227) atom emits an alpha particle, it does so with great force, and the actinium X experiences a recoil.
Indeed, Fermi discovered elements he did not recognise. He tested for elements below uranium in the periodic table: radon, actinium, polonium, as far back as lead – it was none of these. So, in 1934, the infallible Fermi declared to the world he had created elements heavier than uranium.
The new name meant "(nuclear) precursor of actinium," [9] suggesting that actinium is a product of radioactive decay of protactinium. John Arnold Cranston (working with Frederick Soddy and Ada Hitchins ) is also credited with discovering the most stable isotope in 1915, but he delayed his announcement due to being called for service in the ...
In 1859, gold was discovered in California by a group of prospectors, including a tin manufacturer named W.S. Bodey. And the Gold Rush began. Inside an eerie California gold rush town that laid ...