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
Discover: The World of Science Discover: The World of Science Discover: The World of Science is an American television show that ran between 1983 and 1990. Actor Peter Graves is the on-camera host and narrator of "Discover: The World of Science", a monthly, one-hour magazine-style television series which provides a human perspective on new developments in robots, science, technology, medicine, the environment, behavior and natural history. The series was typically broadcast on Wednesday evenings at 8 PM on PBS. The series, with early episodes being underwritten by Atari and later episodes being underwritten by GTE, was produced by Chedd-Angier Productions in association with Discover Magazine.