December 21, 1898 –
Radium, which existed since the world was young, was minding it own business when French local busybodies and known chemists Pierre and Marie Curie isolated radium; one of the first radioactive elements to be discovered. They won a joint Nobel prize for their work, and Marie Curie went on to win another for her contributions to chemistry.
Marie Curie died of aplastic anemia as a result of overexposure to radium, which probably showed her not to play with radioactive elements.
And so it goes
