Group 3 element it from pitchblende residues left by Marie and Pierre Curie after they had extracted radium. In 1899, Debierne described the substance as similar to titanium and (in 1900) as similar to thorium. Friedrich Oskar Giesel independently discovered actinium in 1902 as a substance being similar to lanthanum and called it "emanium" in 1904. After a comparison of the substances half-lives determined by Debierne, Hariett Brooks in 1904, and Otto Hahn and Otto Sackur in 1905, Debierne's chosen name for the new element was retained because it had seniority, despite the contradicting chemical properties he claimed for the element at different
Uranium nitride and, in particular, it undergoes an (n,p) reaction which produces significant amounts of radioactive C which would need to be carefully contained and sequestered during reprocessing or permanent storage. Each uranium dinitride complex is considered to have three distinct compounds present simultaneously because of decomposing of uranium dinitride (UN) into uranium sesquinitride (UN), and the uranium mononitride (UN). Uranium dinitrides decompose to uranium mononitride by the following sequence of reactions: Decomposition of UN is the most common method for isolating uranium sesquinitride (UN). Uranium mononitride is being considered as a potential fuel for generation IV reactors such as the Hyperion