June 15, 2020
For educational institutions
⟶ Updated 6 Oct 2017 ⟶
List of edits
1803 - Dalton proposes his Atomic Theory, stating that all substances are made of atoms.
400 BC - Democritus proposes first idea about the atom
340 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.
About & Feedback