History of the Atomic Theory

By Weapnv200
  • 442 BCE

    Democritus

    Democritus created the first atomic model in 442 BC.
    He stated that matter consists with invisible particles called atoms an empty space, and they are indestructible and unchangeable.

  • John Dalton

    John Dalton formed his idea from 1803-1805. He calls it the Billiard Ball Model, and he formed the Atomic Theory of Matter.

  • JJ Thompson

    JJ Thompson put his Atomic Model forward in 1904, and calls it Plum Pudding Model. His theory is that each atom was a sphere, and is filled with a positively charged fluid. And in the fluid, there were negatively charged electrons,

  • Ernest Rutherford

    Ernest Rutherford put forward his model in 1911 and he called it the Planetary Model.
    Rutherford proposed that atoms consists of a dense center filled with positive charges, which he named the nucleus. Rutherford also said that there were negatively charged electrons were scattered and surrounding the nucleus and are held in orbit due to the electrical forces.

  • Niels Bohr

    Niels Bohr put forward his atomic model in 1913, and calls it the Energy level model.
    Bohr's model is similar to Rutherford’s, both containing the positively charged nucleus. but Bohr said that the electrons is moving in a fixed, circular orbit around the nucleus.

  • James Chadwick

    James Chadwick discovered the neutrons in 1932, and before he discovered the neutrons, people thought there was only protons and electrons.