Radioactivity
Year of Discovery: 1901
What Is It? Atoms are not solid balls and the smallest possible particles of
matter, but contain a number of smaller particles within them.
Who Discovered It? Marie Curie
Why Is This One of the 100 Greatest?
Marie Curie’s discovery of two naturally radioactive elements, polonium and radium,
made headline news, but her real discovery was that atoms were not small solid balls and
that there must be even smaller particles inside them. This discovery opened the door to all
atomic and subatomic research and even to the splitting of the atom.
Curie carried out her research with radioactive elements before the dangers of radioactivity were understood. She suffered from ill health (radiation sickness) for most of her
adult life. Indeed, for many years after her death, her notebooks were still highly
radioactive.
Marie Curie’s studies rank as one of the great turning points of science. Physics after
Curie was completely different than before and focused on the undiscovered subatomic
world. She cracked open a door that penetrated inside the atom and has led to most of the
greatest advances of twentieth-century physics.
How Was It Discovered?
In 1896 Marie Curie decided to complete her doctoral dissertation in a totally new
field: radiation. It was exciting. It was something no one had ever seen or studied before.
66?V?F?7G2??WrF?BV?V7G&?6??6?&vVB&F?F???f???FVBF?R?"&?V?BW&??V??'WB??@??V6?V?6Rv2???v???&?RW6VBFWf?6R?W"?W6&?B?&?fW76?"?W'&R7W&?R???fV?FVBF??FWFV7BV?V7G&?26?&vW2&?V?B??W&?6??W2?6?R??VBF??2&?6W72&F??7F?f?G??@?6??6?VFVBF?B&F??7F?f?G?v2V?GFVBg&????6?FRW&??V?F????6??6RF?R7W&?W2?B?B?????W??bF?V?"?v?F??f?"?W"&W6V&6???B6??6RF?P?V??fW'6?G?&VgW6VBF?gV?Bv???( ?2w&GVFR??WfV???6?72&W6V&6???&?R67&?V?vVBf? ?g&VR?"76R?6?Rf?V?B?&?F??VB6?VBF?B?B&VV?W6VB'?F?R&????w?FW'F?V?@?F????B6FfW'2??Bv2V?&V&&???B??F?R7V??W"?Bg&VW???r6??B??F?Rv??FW"?v?F??fWrv??FV?F&?W2?B6??'2?B'W7G???B7F?fR??????&?Rv2v?fV?W????rW&??V???W&??&R6??VB?F6?&?V?FR?v??6??W ?FW7G26??vVBvfR?fb??&R&F??7F?fRV?76???2F??W?V7FVBg&??F?R??V?B?bW&??P??