The discovery of radium and polonium, and the study of radioactive emissions were the result of the ongoing investigations and the joint work of the French couple Marie and Pierre Curie. Both were physical, and shared with Antoine Henri Becquerel, the Nobel Prize for Physics in 1903. Marie Sklodowska was born in Warsaw (Poland) in 1867, studied at the Sorbonne and met Pierre. He was born in 1859, had done important research on piezoelectricity (production of electrical currents through the pressure on quartz crystals.) They married in 1895 and both continued research on radioactivity. The analysis of various uranium minerals were allowed to see that some of them were more active than pure uranium, and therefore assumed that in such minerals were small particles of another element more radioactive than uranium itself. The Curies proposed to separate this element is unknown and, after four years of work, was isolated 0.2 grams of radium bromide from a thousand pounds of pitchblende. They found that the nuclei of elements such as radium, uranium, polonium and other decay with emission of radiation.
Marie also conducted research on the radio and its compounds, prompting the distinguished with a second Nobel prize for chemistry in 1911.
Marie and Pierre died in a tragic way. Pierre died in a street accident in 1906. Marie died of leukemia in 1934, due to excessive exposure to radioactive elements your body.