Atomic Theory Timeline

By MD1
  • Ancient Greece
    400 BCE

    Ancient Greece

    Democritus said that matter is composed of indivisible particles called atomos, this made the ground for the atomic theory timeline.
  • Dalton's Model

    Dalton's Model

    Dalton expressed that all matter is made of indivisible atoms and that atoms of and element are the same , but atoms of a different element are different, and compounds form from mixed ratios of these atoms, with reactions repositioning them.
  • J.J Thomson's Model

    J.J Thomson's Model

    JJ's Model called the plum pudding model consists of spheres of atoms with diffuse positive charge with negatively charged electrons embedded in it like plum and pudding.
  • Rutherfold's Model

    Rutherfold's Model

    His model describes the atom as mostly empty space with a tiny, dense, positively charged center called the nucleus. The nucleus contains most of the atom's mass with light, negative electrons orbiting it, similar to planets revolving around the sun.
  • Bohr's Planetary Orbit

    Bohr's Planetary Orbit

    This model shows an electron orbiting around the central nucleus, like how the planets orbit around the sun.
  • James Chadwick's Discovery

    James Chadwick's Discovery

    Chadwick discovered the neutron by bombarding beryllium with alpha particles and observing the release of highly penetrating radiation.
  • How the atomic theory timeline helps the understanding of the atom

    The Atomic Theory Timeline helps us understand the atom by explaining chemical properties and showing models that we can remember by making our own little fun models and referencing them by.