Scientists

  • Period: 200 to

    Scientist Over Time

  • Democritis
    460

    Democritis

    Born in 460 BC in Abdera, north of Greece. He discovered the atomic theory. His work on the atomic structure is relativily close to modern viewpoints.
  • John Dalton

    John Dalton

    Dalton lived in Eaglesfield, England. He believed that atoms were invisible and were reearranged in chemical reactions. His four postulates form Dalton's Atomic Theory. He was also the first to discover color-blindness.
  • Sir William Crooke

    Sir William Crooke

    Crooke lived in London. He created the glass tube to make cathode rays that appeared as a glowing blue light from the interaction of the electric current.
  • Dmitri Mendeleev

    Dmitri Mendeleev

    Mendeleev was born in Tobolsk, Siberia. He formed the first Periodic Table composed of elements arranged in ascending order of atomic weight and grouped them by similar properties.
  • John Newlands

    John Newlands

    He was born in London. Newlands created the Law of Octaves which stated every eighth element has similar properties. His only flaw was that the law only worked up to the element of calcium. He came very close to discovering the periodic table. He also classified elements relative to their atomic masses.
  • JJ Thomson

    JJ Thomson

    Lived in Manchester, England. He conducted experiments with cathode ray tubes and discovered the electron. He also proposed the plum pudding model of the atom.
  • Ernest Rutherford

    Ernest Rutherford

    Rutherford lived in Brightwater, New Zealand. He discovered the nucleus and conducted an experiement using gold foil.
  • Niels Bohr

    Niels Bohr

    Bohr was born in Copenhagen, Denmark. He discovered that electrons obrit the nucleus at set distances only changing levels when energy is lost or when more energy is obtained. He had his own model called Bohr's Atomic Model.
  • Aristotle

    Aristotle

    Lived in Tharce near Aegean. He discovered that the earth was round and developed the theory of elements. He also had his own Laws of Motion Theory.