Plonoium

Polonium is a highly radioactive and rare metalloid or post-transition metal with the chemical symbol of Po. In 1898 a polish chemist named Marie Sklodowska Curie discovered the element of Polonium by noticing a material named Pitchblende, a material with Uranium in it was more radioactive than uranium itself. Thus, she separated the uranium and Polonium from Pitchblende to discover this new element.