Hannah J 8

By Hannahjones922
  • 440 BCE

    Plato atom

    Plato atom
    solid forms of matter are composed of indivisible elements shaped like triangles
  • 400 BCE

    Democritus

    Democritus
    atoms were uniform, solid, hard, incompressible, and indestructible and that they moved in infinite numbers through empty space until stopped.
  • 330 BCE

    Aristotle

    Aristotle
    the four elements were not composed of atoms but were continuous forms of matter.

  • Robert Boyle

    Robert Boyle
    He believed that everything was composed of very tiny particles, an idea known as atomism

  • Newton Law

    Newton Law
    the behavior of the sub-atomic particles cannot be described by Netwon's Laws.

  • John Dalton

    John Dalton
    all matter is made of atoms, which are indivisible.

  • Newland’s Law of Octaves

    Newland’s Law of Octaves
    if the chemical elements are arranged according to increasing atomic weight, those with similar physical and chemical properties occur after each interval of seven elements.

  • Mendeleev’s Pd. Table

    Mendeleev’s Pd. Table
    all of the elements positioned within a logical matrix.

  • Discovery of Radioactivity

    Discovery of Radioactivity
    The radioactivity of uranium was discovered in 1896 by Henri Becquerel who, starting from a wrong idea, progressively realized what he was observing, regularly informing the French Academy of Sciences of the progress he was doing.

  • Planck’s Theory of Light

    Planck’s Theory of Light
    light exists as tiny massless particles called photons which exhibit wave-particle duality,

  • Plum Pudding Model

    Plum Pudding Model
    the electrons were embedded in a uniform sphere of positive charge, like blueberries stuck into a muffin

  • Robert Millikan

    Robert Millikan
    precisely determining the magnitude of the electron's charge

  • Rutherford’s Gold Foil Experiment

    Rutherford’s Gold Foil Experiment
    consists of a small, massive, positively charged nucleus with the negatively charged electrons being at a great distance from the centre.

  • Bohr’s Planetary Model

    Bohr’s Planetary Model
    the electrons encircle the nucleus of the atom in specific allowable paths called orbits.

  • Moseley’s Atomic

    Moseley’s Atomic
    the atomic number is the number of positive charges in the atomic nucleus.

  • Discovery of the Proton

    Discovery of the Proton
    The discovery of the proton is credited to Ernest Rutherford, who proved that the nucleus of the hydrogen atom

  • Photoelectric Effect

    Photoelectric Effect
    The photoelectric effect is the process whereby the energy from electromagnetic radiation, such as visible light, gamma radiation or other, hits an atomic electron whereby the energy of the radiation is transferred in its entirety to the electron causing the electron to be ejected from the atom.

  • schrodinger atomic

    schrodinger atomic
    based on the quantum mechanical and wave nature of electrons

  • Heisenberg Uncertainty Principle

    Heisenberg Uncertainty Principle
    we cannot know both the position and speed of a particle, such as a photon or electron, with perfect accuracy;

  • Discovery of the Neutron

    Discovery of the Neutron
    n May 1932 James Chadwick announced that the core also contained a new uncharged particle, which he called the neutron. Chadwick was born in1891 in Manchester, England.