В1898 г. Мария и Пьер Кюри открыли радий

Since the very discovery of radioactivity that had been discovered by Henri Becquerel in 1896, Marie Curie began studying radioactive materials. Soon she found out that uranium ore or pitch ore electrified the surrounding air much more strongly than uranium and thorium compounds contained in it. Marie Curie made a conclusion on the presence of a strong radioactive element in the uranium ore. She called the first element polonium in honor of her motherland and the second one – radium. Pierre Curie appreciated the importance of his wife’s discoveries and joined in her research. In the following 4 years, without any lab, literarily in a barn, the spouses washed tons of uranium ore to extract enough radium to determine its atomic weight. The radium they discovered did not make them rich, though it could as it is rather rare in nature. However, the Curies refused to patent it or use it for commercial purposes as it contradicted the spirit of science, i.e., the free exchange of knowledge. However, they were rewarded with Nobel prize in physics and Marie even got the second one in chemistry. When in the early 1920s she made a triumphant tour of the USA, the president gave her a gift of 1 gram of radium. It was purchase with the money deliberately collected by American ladies.