Atom

Atomic Theory Scientists

By noahcooley
  • 200

    Democritus creates the idea of atoms.

    Democritus creates the idea of atoms.
    460 BCE - Democritus shares his idea that everything is made up of small, unbreakable things.

  • John Dalton created Atomic Theories.

    John Dalton created Atomic Theories.
    John Dalton created 4 atomic theories about the atom.

  • Crookes discovers cathode rays.

    Crookes discovers cathode rays.
    Sir William Crookes found cathode rays, which are rays emitted from electrons.

  • Thomson discovers the electron.

    Thomson discovers the electron.
    Thomson found the electron and thought that electrons were "swimming" in the proton - known as the plum pudding model.

  • Einstein calculates size of atoms.

    Einstein calculates size of atoms.
    Einstein calculated the size of many atoms and molecules using a formula.

  • Rutherford discovers the nucleus.

    Rutherford discovers the nucleus.
    Rutherford found that there was a nucleus that was surrounded by the electrons,

  • Bohr discovers electron shells; creates model.

    Bohr discovers electron shells; creates model.
    Bohr guessed that electrons have predetermined paths that they constantly travel along. This is a really famous model, known as the Bohr model.

  • Chadwick discovers neutron.

    Chadwick discovers neutron.
    James Chadwick found that the nucleus also contains a neutral charged atom - a neutron.