Period 7 element elements of the 7th period. Francium is a chemical element with symbol Fr and atomic number 87. It was formerly known as eka-caesium and actinium K. It is one of the two least electronegative elements, the other being caesium. Francium is a highly radioactive metal that decays into astatine, radium, and radon. As an alkali metal, it has one valence electron. Francium was discovered by Marguerite Perey in France (from which the element takes its name) in 1939. It was the last element discovered in nature, rather than by synthesis. Outside the laboratory, francium is extremely rare, with trace amounts
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