-
460
Democritis
He first proposed the existance of an ultimate particle. -
John Dalton (1766-1844).
Proposed an "atomic theory" with spherical solid atoms based upon measurable properties of mass. -
Dmitri Mendeleev
Proposed the perodic law asnd developed the first periodic table -
John (J. J.) Thomson
Studied "canal rays" and found they were associated with the proton H+ . -
Robert Milikan
Determined the unit of charge of the electron -
Ernest Rutherford
publishes his atomic theory describing the atom as having a central positive nucleus surrounded by negative orbiting electrons. -
Henri Moseley
Discovered Moseley's law is an empirical law concerning the characteristic x-rays that are emitted by atoms. -
Heisenberg
He is best known for his uncertainty principle, which restricts the accuracy with which some properties of atoms and particles--such as position and linear momentum--can be determined simultaneously -
James Chadwick
discovered a third type of subatomic particle, which he named the neutron. -
Erwin Schrodinger
Edwin Schrodinger stated that rather than electrons being distributed within an electron configuration of shells and energy levels, they were arranged in orbitals which were systematically distributed within Electron Clouds.
