Events
1803 - Dalton proposes his Atomic Theory, stating that
all substances are made of atoms.400 BC - Democritus proposes first idea about the atom340 BC - Aristotle proposes his theory about the
elements, stating that all things are composed of
fire, earth, air, and water.1897 - Thomson discovered that atoms are in fact
divisible, and composed of smaller charged particles.1909 - Millikan discovers that the almost massless
electrons have an extremely negative charge,
through his oil drop experiment.1911 - Rutherford performs his gold foil experiment
and is able to discover the postitvely charged
nucleus of the atom.1913 - Bohr proposed a new model of the atom,
in which the electrons are traveling around the nucleus
in orbitals.1928 - Schrodinger argues against Bohr's model
claiming electrons to be more accurately viewed
in "clouds."1924 - De Brogile proposes that atoms can travel
in waves.1932 - Chadwick is able to discover the neutron.
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