The History of the Atom

By 15sdillon

  • Alchemists, approx 480 BC

    Alchemists, approx 480 BC
    They searched for the Philosophers stone, which could turn simple materials into valuable substances like gold.

  • Democritus, approx 400 BC

    Democritus, approx 400 BC
    Greece-- Democritus stated that all matter is made up of atoms, and that atoms are eternal and invisible and so small that they can’t be divided, and they fill up the space they’re in.

  • Aristotle, approx 380 BC

    Aristotle, approx 380 BC
    Greece- provided the method of gathering scientific facts, which proved as the basis of scientific work.

  • Isaac Newton

    Isaac Newton
    Proposed a mechanical universe with small solid masses in motion.

  • Lavoisler

    Lavoisler
    France - Provided the formula for the conservation of matter in chemical reactions; he distinguished between an element and a compound.

  • Couloumb

    Couloumb
    France- made Coulomb's law, stating that the force between two electrical charges is proportional to the product of the charges and inversely proportional to the square of the distance between them, one of the main forces involved in atomic reactions.

  • Dalton

    Dalton
    England- Dalton formed the atomic theory, stating that all matter is composed of atoms that are all alike and have the same atomic weight.

  • Crookes

    Crookes
    England - He created the Crookes’ tube and demonstrated that cathode rays travel in straight lines and produce phosphorescence and heat when they strike certain materials.

  • WK Roentgen

    WK Roentgen
    Germany - discovered x-rays while experimenting with cathode-ray tubes.

  • Thomson

    Thomson
    England- He developed the plum-pudding model of the atom and discovered the electron.

  • The Curies

    The Curies
    France - discovered radium and polonium when they started to investigate radioactive substances.

  • Max Planck

    Max Planck
    Germany- PLanck started the quantum theory.

  • Robert Millikan

    Robert Millikan
    USA- found out the electric charge of the electron.

  • Rutherford

    Rutherford
    England- used the results of his gold-foil experiment to state that all the mass of an atom was in a small postievely-charged ball at the center of the atom.

  • Bohr

    Bohr
    Denmark- Said that electrons moved around the nucleus in sucessively large orbits. presented the Bohr model, stating tjat atoms absorb or emit radiation only when the electrons jump between allowed states.

  • Chadwick

    Chadwick
    England - discovered the neutrally-charged neutron.