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Perey announced the discovery of the never-before-seen element 87 as a note in the Comptes Rendus presented at the Académie des Sciences by Jean Baptiste Perrin on 9 January 1939 with the title "On an element 87, derived from actinium." [5] Perey's discovery was announced by Perrin, not Perey herself, because she was only a laboratory ...
[5] [6] He was aware of the discovery of actinium by André-Louis Debierne. In publications from 1899 and 1900 Debierne does not give the exact procedures to obtain actinium, but from the description of chemical properties which he described as similar to titanium (1899) or similar to thorium (1900) it was clear for Giesel that the two elements ...
Actinium is a soft, silvery-white, [17] [18] radioactive, metallic element. Its estimated shear modulus is similar to that of lead. [19] Owing to its strong radioactivity, actinium glows in the dark with a pale blue light, which originates from the surrounding air ionized by the emitted energetic particles. [20]
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 discovery of actinium by Debierne was however questioned in 1971 [27] and 2000, [28] arguing that Debierne's publications in 1904 contradicted his earlier work of 1899–1900. This view instead credits the 1902 work of Friedrich Oskar Giesel , who discovered a radioactive element named emanium that behaved similarly to lanthanum.
The decay chain of actinium. Alpha decay shifts two elements down; beta decay shifts one element up.. Soddy and Kasimir Fajans independently observed in 1913 that alpha decay caused atoms to shift down two places in the periodic table, while the loss of two beta particles restored it to its original position.
Lise Meitner (/ ˈ l iː z ə ˈ m aɪ t n ər /, LEE-zə MYTE-nər; German: [ˈliːzə ˈmaɪtnɐ] ⓘ; born Elise Meitner, 7 November 1878 – 27 October 1968) was an Austrian-Swedish nuclear physicist who was instrumental in the discovery of nuclear fission.
Discovery Museum is a hands-on museum for families that blends science, nature, and play, located in Acton, Massachusetts, United States.After an $8.8M expansion and renovation, the museum reopened in March 2018 as a 16,000 sq ft (1,500 m 2), accessible, single-building museum; a 550 sq ft (51 m 2) tree house and accessible nature playscape were added to the campus in July 2016. [1]