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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.
André-Louis Debierne had previously (in 1899 and 1900) reported the discovery of a new element actinium that was supposedly similar to titanium and thorium, which cannot have included much actual element 89. But by 1904, when Giesel and Debierne met, both had radiochemically pure element 89, and so Debierne has generally been given credit for ...
Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free element. 89 Y is the only stable isotope and the only isotope found in the Earth's crust. The most important present-day use of yttrium is as a component of phosphors, especially those used in LEDs.
So, element 105 was named dubnium, and element 106 was named seaborgium. The elements were placed in the periodic table’s seventh row, which is above the row of lanthanides and the row of actinides.
A Nobel laureate who spearheaded the first discoveries of transuranium elements was Glenn Seaborg. In December 1940, his team working at the 60-inch cyclotron at the Lawrence Radiation Laboratory ...
The actinide (/ ˈ æ k t ɪ n aɪ d /) or actinoid (/ ˈ æ k t ɪ n ɔɪ d /) series encompasses at least the 14 metallic chemical elements in the 5f series, with atomic numbers from 89 to 102, actinium through nobelium. Number 103, lawrencium, is also generally included despite being part of the 6d transition series. The actinide series ...
Loss of an alpha particle (consisting of 2 protons and 2 neutrons) would turn actinium (element 89, with 89 protons) into the theorized but never-before-seen element 87. [ 3 ] 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 ...
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...