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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.
Malakoff Diggins State Historic Park is a state park unit preserving Malakoff Diggins, the largest hydraulic mining site in California, United States.The mine was one of several hydraulic mining sites at the center of the 1882 landmark case Woodruff v.
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.
Whitney organized the first comprehensive survey of California, and the first complete topographic maps of the state were completed under him. Mount Whitney, the tallest peak in California is named after him. The State Mining Bureau was established in 1880, and the position of State Geologist was changed to State Mineralogist.
Friedrich Oskar Giesel (20 May 1852 – 13 November 1927, known as Fritz) was a German organic chemist.During his work in a quinine factory in the late 1890s, he started to work on the at-that-time-new field of radiochemistry and started the production of radium.
In 1899, he discovered the radioactive element actinium, as a result of continuing the work with pitchblende that the Curies had initiated. After the death of Pierre Curie in 1906, Debierne helped Marie Curie carry on and worked with her in teaching and research. In 1911, he and Marie Curie prepared radium in metallic form in visible amounts ...
Actinium-225 is a member of the radioactive neptunium series; [60] it was first discovered in 1947 as a decay product of uranium-233 and it is an α-emitter with a half-life of 10 days. Actinium-225 is less available than actinium-228, but is more promising in radiotracer applications. [30]
On June 29, 1952, the McKittrick Tar Pits were registered a California Historical Landmark. California Historical Landmark reads: NO. 498 McKITTRICK BREA PIT - Located one-eighth mile west of here is an ancient asphaltum seepage in which hundreds of Pleistocene Age (15,000-50,000 years ago) birds and animals were trapped.