The Development of the Atomic Theory

By Cheryll Tirtadidjaja
  • 490 BCE

    Democritus

    Everything is composed of “atoms”, which are physically, but not geometrically, indivisible.

  • John Dalton

  • Sir J.J Thompson

  • Lord Rutherford

  • Niels Bohr

    Niels Bohr
    Niels Bohr proposed a hypothesis for the hydrogen molecule based on quantum theory that vitality is moved just in certain very much characterised amounts. Electrons should move around the core however just in endorsed circles. When bouncing starting with one circle then onto the next with bring down vitality, a light quantum is discharged.

  • Sir James Chadwick

    Sir James Chadwick
    Until 1932, the atom was accepted to be made out of a positive charged core surrounded by negative charged electrons. In 1932, James Chadwick created beryllium atoms with alpha particles. An unknown radiation was created. This particle wound up known as the neutron.