atom

By johnny zacharias
  • Period: Jan 1, 1300 to

    date

  • John Dolton

    Proposed an "atomic theory" with spherical solid atoms based upon measurable properties of mass.

  • 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.