jan 1, 1905 - Marie and Pierre Curie
Description:
Henry shared his discovery with Marie and Pierre Curie. Marie called elements that spontaneously emit radiation radioactive. This radiation came from the nuclei of atoms. When this happens, number of protons in one atom of uranium changes. When it releases radiation it changes to a different element.Added to timeline:
Date:
jan 1, 1905
Now
~ 120 years ago