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
Naturally occurring radioactive material UK regulation is via the Environmental Permitting (England and Wales)Regulations 2010. This defines two types of NORM activity: (a)the production and use of thorium, or thorium compounds, and the production of products where thorium is deliberately added; or (b)the production and use of uranium or uranium compounds, and the production of products where uranium is deliberately added (a)the extraction, production and use of rare earth elements and rare earth element alloys; (b)the mining and processing of ores other than uranium ore; (c)the production of oil and gas; (d)the removal and management of radioactive scales and precipitates from equipment associated with