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
Kermes mineral Kermes mineral Kermes mineral or Alkermes mineral was a compound of antimony oxides and sulfides, more specifically, antimony trioxide and trisulfide. It can be made or obtained in the laboratory by the actions of potassium carbonate (KCO) on antimony sulfide. The compound is reddish brown in color and described as a velvety powder which is insoluble in water. It was used extensively in the medical field until the general use of antimony compounds declined due to toxic effects. The name is derived from the word "kermes" as denoting the compound’s red color. The origins of the term is from the