Question #2b905
1 Answer
The following timeline of the atomic model is highly condensed and omits many important contributions.
442 BC — Democritus/Leucippus — matter consists of indivisible particles.
1777 — Lavoisier — Law of Conservation of Mass
1803 — John Dalton — atomic theory of matter
1869 — Dmitri Mendeleev — Periodic Table and periodic law
1897 — J. J. Thomson — discovers electron
1898 — J. J. Thomson— plum pudding model of atom
1898 — Ernest Rutherford — discovers α and β rays
1900 — Frederick Soddy — discovers radioactive decay
1900 — Max Planck — quantum theory of energy
1905 — Albert Einstein — Quantization of light;
1909 — Ernest Rutherford — nuclear model of atom
1913 — Niels Bohr — orbital model of atom
1914 — H. G. J. Moseley — measures atomic numbers of nuclei
1923 — Louis de Broglie — discovers wave/particle duality
1926 — Erwin Schrödinger — develops Schrödinger equation
1930 — Paul Dirac — proposes anti-particles
1932 — Carl Anderson — discovers positron
1932 — James Chadwick — discovers neutron
1955 — Segrè/Chamberlain — discover antiproton
1955 on — many new discoveries about subatomic particles
