Atomic Theory

Timeline created by vpatel
  • 300

    Aristotle's Theory

    Aristotle's Theory
    Mid 300s B.C.E Aristotle strongly disagreed with Democritus.
    His theorey used great generalization
    It stated that there were 4 elements: earth, fire, air, water with 4 quantities: warm, dry, cool, moist'
    It was used for about 2000 years while the Democritus Model was put aside
  • Period:

    Atomic Theory

  • 400

    Basic Atomic Theory

    Basic Atomic Theory
    5th Century B.C.E Democritus said all things were composed of extremely small things called "atomos"
    He stated nothing exists except atoms and empty space.
    This is the first atomic theory known to man
  • Modern Atomic Theory

    Modern Atomic Theory
    John Dalton announced his theory 1) All elements consist of minuscule particles called atoms.
    2) All atoms in an element are identical to each other.
    3) All atoms in an element are different than those of other elements.
    4) Atoms of one element combine with other elements to create compounds. They always combine in equal amounts.
    5) Atoms cannot be created, divided, or destroyed.
  • The Electron

    The Electron
    JJ Thompson disxcovers the electron
    He comes up wityh the Plum Pudding model
  • Quantam Theory

    Quantam Theory
    Max Planck introduced the quantam theory
    Atoms can emit quanta
  • Rutherford

    Performed the gold foil expirement
    the atom is mostly empty space with a small positively charged nucleus containing most of the mass and low mass negatively charged particles orbiting this nucleus.
    Predicted the nuetron
  • Oil Drop Expirement

    Oil Drop Expirement
    It was used to find the charge of an electron
    It was completed by Robert Millikan and JJ Thompson
  • Bohr's Model

    Bohr's Model
    Niels Bhor introduced his representation of the atom
    His model is known as the planetary model.
    Stated that the electrons moved around the nucleus in large orbits
    Stated that atoms absorb or emit radiation only when the electrons abruptly jump between allowed, or stationary, states.
  • Louis de Broglie

    Louis de Broglie
    introduced his theory of particle-wave duality
    stated particles can behave like waves, and waves (radiation) can behave like particles
    was fundamental for quatam mechanical model
    Inspired Schrodinger
  • Dual Nature of Light

    Dual Nature of Light
    The wave equation was confirmed mathematically by Erwin Schrodinger.
    The equation helped determine probability location of electrons in an atom
  • Uncertainty Principle

    Uncertainty Principle
    Werner Heisenberg stated that it's impossible to determine locaton and momentum of electrons simultaneously.
    That is why they are described in orbitals instead of orbits
    "cloud model aka quantam mechanical model"
  • The Neutron

    The Neutron
    Although Rutherford predicted it, the neutron wasn't discovered until 1932 by James Chadwick.
    Chadwick used scattering data to calculate the mass of this neutral particle