Radium seventh of a gram of radium. One kilogram of the Earth's crust contains about 900 picograms of radium, and one liter of sea water contains about 89 femtograms of radium. Radium was discovered by Marie Sklodowska-Curie and her husband Pierre Curie on 21 December 1898, in a uraninite (pitchblende) sample. While studying the mineral earlier, the Curies removed uranium from it and found that the remaining material was still radioactive. They separated out an element similar to bismuth from pitchblende in July 1898, that turned out to be polonium. They then separated out a radioactive mixture consisting mostly of two
The Apocalypse Element galaxy. The Apocalypse Element The Apocalypse Element is a Big Finish Productions audio drama based on the long-running British science fiction television series "Doctor Who". It forms the second serial in the Dalek Empire arc, following on from events in "The Genocide Machine". The arc continues in "The Mutant Phase" and concludes in "The Time of the Daleks". At a conference on Archetryx between major temporal powers, the Sixth Doctor and Evelyn discover that Romana has been missing for twenty years and that the Daleks' newest weapon — the Apocalypse Element — threatens not only the Time Lords but the