Timeline created by jacylyn
  • First Element Discovered

    Development of The Periodic TableHennig Brand discovers Phosphorus through scientific inquiry.
  • Dalton's Atomic Theory

    Dalton's Atomic Theory
    Dalton Atomic TheoryAll matter is composed of atoms
    Stated the following:
    Atoms cannot be made or destroyed
    All atoms of the same element are identical
    Different elements have different types of atoms
    Chemical reactions occur when atoms are rearranged
    Compounds are formed from atoms of the constituent elements
  • Döbereiner's Law of Triads

    Döbereiner's Law of Triads
    Döbereiner's Periodic TableEach of Dobereiner's triads was a group of three elements. The appearance and reactions of the elements in a triad were similar to each other.
  • Use of Atomic Weights

    [Precursors to the Periodic Table](http: de Chancourtois was the first person to make use of atomic weights to reveal that the elements were arranged according to their atomic weights.
  • Law of Octaves

    Precursors to the Periodic TableJohn Newlands, an English chemist, proposed the Law of Octaves which stated that elements repeated their chemical properties every eighth element.
  • More Element Discoveries

    Development of The Periodic Table63 elements have been discovered.
  • Thomson Model of The Atom

    Thomson Model of The Atom
    Atomic ModelJoseph John ThomsonThomson suggested a model of the atom as a sphere of positive matter in which electrons are positioned by electrostatic forces.
  • Rutherford Atomic Model

    Rutherford Atomic Model
    ModelRutherford ModelStates the atom as having negative orbiting electrons. Also, most of the mass of the atom was contained in the small nucleus, and that the rest of the atom was mostly empty space
  • Bohr Atomic Theory

    Bohr Atomic Theory
    Bohr Atomic StructureBohr Model
    Bohr suggested the revolutionary idea that electrons "jump" between energy levels (orbits) in a quantum fashion.