History of chemistry element among the fractions that resulted. Working with the mineral pitchblende, the pair discovered a new radioactive element in 1898. They named the element polonium, after Marie's native country of Poland. On December 21, 1898, the Curies detected the presence of another radioactive material in the pitchblende. They presented this finding to the French Academy of Sciences on December 26, proposing that the new element be called radium. The Curies then went to work isolating polonium and radium from naturally occurring compounds to prove that they were new elements. In 1902, the Curies announced that they had produced a decigram
Polonium and sources of neutrons and alpha particles. This radioactivity makes polonium dangerously toxic. Po is an alpha emitter that has a half-life of 138.4 days; it decays directly to its stable daughter isotope, Pb. A milligram (5 curies) of Po emits about as many alpha particles per second as 5 grams of Ra. A few curies (1 curie equals 37 gigabecquerels, 1 Ci = 37 GBq) of Po emit a blue glow which is caused by ionisation of the surrounding air. About one in 100,000 alpha emissions causes an excitation in the nucleus which then results in the emission of