Contributions to the atomic theory

  • Democritus
    400 BCE

    Democritus

    Democritus discovered the atom
  • John Dalton

    John Dalton

    He developed ways to find out the weight and the structures of the formulated law of partial pressures
  • JJ Thompson

    JJ Thompson

    He experimented with cathode ray tubes and showed that all atoms contain a negative charge
  • Ernest Rutherford

    Ernest Rutherford

    He discovered nuclear physics and discovered that all atoms have a nucleus that is surrounded by empty space and circled by tiny electrons
  • Niels Bohr

    Niels Bohr

    Bohr was the first person to discover thatt electrons travel in separate orbits around the nucleus
  • James Chadwick

    James Chadwick

    He proved the existence of neutrons