Atomic Model Timelime

By GabbyV
  • Dalton's Theory

    Dalton's Theory
    John Dalton pictures atoms as tiny, indestructible particles, with no internal structure.
  • Dmitri Mendeleev

    Dmitri Mendeleev
    Arranged elements into 7 groups with similar properties. He discovered that the properties of elements "were periodic functions of the their atomic weights". This became known as the Periodic Law.
  • Sir William Crookes

    Sir William Crookes
    Discovered cathode rays had the following properties: travel in straight lines from the cathode; cause glass to fluoresce; impart a negative charge to objects they strike; are deflected by electric fields and magnets to suggest a negative charge; cause pinwheels in their path to spin indicating they have mass.
  • Thomson Theory

    Thomson Theory
    J.J. Thomson, a British scientist, discovers the electron. The later leads to his "plumpudding" model. He pictures electrons embedded in a spere of a positive electrical charge.
  • Albert Einstein

    Albert Einstein
    Made the formula E = mc2
  • Rutherford's Theory

    Rutherford's Theory
    New Zealand physicist Ernest Rutherford finds that an atom has a small, dense positively charged nucleus. Electrons move around the nucleus.
  • Bohr's Theory

    Bohr's Theory
    In Niels Bohr's model, the electron moves in a circular orbit at fixed distances from the nucleus.
  • Wolfgang Pauli

    Wolfgang Pauli
    Austrian physicist, Wolfgang Pauli predicted that an electron should spin (kind of like a top) while it orbits around the nucleus. The electron can spin in either of two direction. This spin consisted of a fourth quantum number: electron spin.
  • Elctron Cloud

    Elctron Cloud
    Erwin Schrodinger develops mathmatical equations to describe the motion of electrons in atoms. His work leads to the electron cloud model.