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
Radium dials loosely referred to as radium jaw. Inhaled or ingested particles may deposit a high local dose with a risk of lung or gastrointestinal cancer due to the radiation dose. The risks are hard to quantify due to the variable levels of radium in the paint and the quantity ingested or inhaled. Care should be taken in handling these materials especially where the paint is damaged. The most common isotope of Radium is Ra, which primarily emits alpha particles. Alpha particles are shielded by most thin materials including paper. However, Ra only emits alpha particles 97 percent of the time with