History of the Atom

By tiawaller
  • Democritus discovered the atom.
    400 BCE

    Democritus discovered the atom.

    state that matter was composed of small particles called "atoms" that could be divided no further. -http://thehistoryoftheatom.weebly.com › democritus
  • John Dalton discovered atoms are building blocks

    John Dalton discovered atoms are building blocks

    all matter was composed of atoms, indivisible and indestructible building blocks.
  • Dmitri Mendeleev forms periodic table

    Dmitri Mendeleev forms periodic table

    Created the periodic classification of the chemical elements.
  • J.J. Thomson discovered the electron

    J.J. Thomson discovered the electron

    J.J. Thomson discovered the electron using the Plum Pudding model.
  • Ernest Rutherford discovered the nucleus.

    Ernest Rutherford discovered the nucleus.

    Ernest Rutherford discovered the nucleus using the gold foil experiment.
  • James Chadwick discovered neutrons

    James Chadwick discovered neutrons

    James Chadwick conducted an experiment in which he bombarded Beryllium with alpha particles from the natural radioactive decay of Polonium. The resulting radiation showed high penetration through a lead shield, which could not be explained via the particles known at that time. - https://www.frm2.tum.de/en/frm2/the-neutron-source/neutrons/how-were-neutrons-discovered/