Atomic Timeline By cwok 401 BCE Democritus discovers the atom 399 BCE World Event: Cyrus the Younger is killed in Persia Apr 30, 1803 World Event: USA purchases a bunch of land from France in the Louisiana Purchase Oct 21, 1803 John Dalton's "Marble" Model Oct 28, 1831 Michael Faraday discovered that atoms have an electrical component. 1886 Eugen Goldstein discovers the existence of the positively charged particle. Apr 30, 1895 JJ Thompson discovers the negatively charged particle, or the electron Sep 6, 1901 World Event: William McKinley assassination 1911 Ernest Rutherford creates "Jimmy Neutron" model of the atom 1913 Robert Millikan discovers the charge of an individual electron 1913 Neils Bohr creates the "Solar System" model of the atom. Jul 28, 1914 World Event: Austria-Hungary declares war on Serbia, beginning World War I. 1926 Erwin Schrodinger creates "electron cloud" model of the atom 1927 Werner Heisenberg discovers that a particle's position and momentum cannot both be known exactly. Oct 24, 1929 World Event: US Stock Market Crash 1932 James Chadwick creates "electron cloud" model of the atom with neutrons added. May 6, 1937 World Event: The Hindenburg Disaster
