Researched
Radioactivity
Becquerel (1896) and the Curies (1898) find that some atoms send out rays by themselves; atoms turn out to be changeable.
Open in the interactive tree →Henri Becquerel noticed in 1896 that uranium salts fog photographic plates in the dark. Marie and Pierre Curie isolated polonium and radium in 1898 and coined the word radioactivity, and Rutherford and Soddy showed in 1902 that radioactive atoms turn into other elements. This broke the idea of indivisible atoms and opened the way to nuclear physics, radiotherapy and radiometric dating.
Prerequisites
- Photography1839
- X-rays1895
Unlocks
- Nucleus & Bohr Atom1911
- Particle Accelerators1932
- Nuclear Physics1938Radioactivity was the starting point of nuclear physics
- Radiocarbon Dating1949
- Radiometric age of the Earth1956Radioactive decay is the clock used for dating rocks