History of the Atom By JoeSmith1993 430 BCE Democritus theorizes the atom 426 BCE Plague of Athens 1799 End of French Revolution 1804 Dalton theorizes the "marble" model 1833 Faraday discovers laws of electrolysis 1886 Goldstein observes electrons 1904 Thomson proposes "plum pudding" model 1905 Russo-Japanese War 1910 Millikan deduces electron charge and mass 1911 Rutherford proposes "nuclear" model 1913 Bohr proposes the "solar system" model 1914 World War I (Start) 1926 Schrödinger creates his equation, requiring "electron cloud" model 1927 Heisenberg proposes uncertainty principle 1929 Start of the Great Depression 1932 Chadwick proves neutrons' existence, providing nucleus structure 1939 German invasion of Poland
