<Table> <Tr> <Th> Time </Th> <Th> Event </Th> </Tr> <Tr> <Td> 1800 </Td> <Td> William Herschel discovers `` heat rays '' </Td> </Tr> <Tr> <Td> 1801 </Td> <Td> Johann Wilhelm Ritter made the hallmark observation that invisible rays just beyond the violet end of the visible spectrum were especially effective at lightening silver chloride - soaked paper . He called them `` oxidizing rays '' to emphasize chemical reactivity and to distinguish them from `` heat rays '' at the other end of the invisible spectrum ( both of which were later determined to be photons ) . The more general term `` chemical rays '' was adopted shortly thereafter to describe the oxidizing rays , and it remained popular throughout the 19th century . The terms chemical and heat rays were eventually dropped in favor of ultraviolet and infrared radiation , respectively . </Td> </Tr> <Tr> <Td> 1895 </Td> <Td> Discovery of the ultraviolet radiation below 200 nm , named vacuum ultraviolet ( later identified as photons ) because it is strongly absorbed by air , by the German physicist Victor Schumann </Td> </Tr> <Tr> <Td> 1895 </Td> <Td> X-ray produced by Wilhelm Röntgen ( later identified as photons ) </Td> </Tr> <Tr> <Td> 1897 </Td> <Td> Electron discovered by J.J. Thomson </Td> </Tr> <Tr> <Td> 1899 </Td> <Td> Alpha particle discovered by Ernest Rutherford in uranium radiation </Td> </Tr> <Tr> <Td> 1900 </Td> <Td> Gamma ray ( a high - energy photon ) discovered by Paul Villard in uranium decay </Td> </Tr> <Tr> <Td> 1911 </Td> <Td> Atomic nucleus identified by Ernest Rutherford , based on scattering observed by Hans Geiger and Ernest Marsden </Td> </Tr> <Tr> <Td> 1919 </Td> <Td> Proton discovered by Ernest Rutherford </Td> </Tr> <Tr> <Td> 1931 </Td> <Td> Deuteron discovered by Harold Urey ( predicted by Rutherford in 1920 ) </Td> </Tr> <Tr> <Td> 1932 </Td> <Td> Neutron discovered by James Chadwick ( predicted by Rutherford in 1920 ) Main article : Discovery of the neutron </Td> </Tr> <Tr> <Td> 1932 </Td> <Td> Antielectron ( or positron ) , the first antiparticle , discovered by Carl D. Anderson ( proposed by Paul Dirac in 1927 and by Ettore Majorana in 1928 ) </Td> </Tr> <Tr> <Td> 1937 </Td> <Td> Muon ( or mu lepton ) discovered by Seth Neddermeyer , Carl D. Anderson , J.C. Street , and E.C. Stevenson , using cloud chamber measurements of cosmic rays ( it was mistaken for the pion until 1947 ) </Td> </Tr> <Tr> <Td> 1947 </Td> <Td> Pion ( or pi meson ) discovered by C.F. Powell 's group , including César Lattes ( first author ) and Giuseppe Occhialini ( predicted by Hideki Yukawa in 1935 ) </Td> </Tr> <Tr> <Td> 1947 </Td> <Td> Kaon ( or K meson ) , the first strange particle , discovered by George Dixon Rochester and Clifford Charles Butler </Td> </Tr> <Tr> <Td> 1950 </Td> <Td> Λ ( or lamda baryon ) discovered during a study of cosmic - ray interactions </Td> </Tr> <Tr> <Td> 1955 </Td> <Td> Antiproton discovered by Owen Chamberlain , Emilio Segrè , Clyde Wiegand , and Thomas Ypsilantis </Td> </Tr> <Tr> <Td> 1956 </Td> <Td> Electron antineutrino detected by Frederick Reines and Clyde Cowan ( proposed by Wolfgang Pauli in 1930 to explain the apparent violation of conservation of energy in beta decay ) At the time it was simply referred to as neutrino since there was only one known neutrino . </Td> </Tr> <Tr> <Td> 1962 </Td> <Td> Muon neutrino ( or mu neutrino ) shown to be distinct from the electron neutrino by a group headed by Leon Lederman </Td> </Tr> <Tr> <Td> 1964 </Td> <Td> Xi baryon discovery at Brookhaven National Laboratory </Td> </Tr> <Tr> <Td> 1969 </Td> <Td> Partons ( internal constituents of hadrons ) observed in deep inelastic scattering experiments between protons and electrons at SLAC ; this was eventually associated with the quark model ( predicted by Murray Gell - Mann and George Zweig in 1964 ) and thus constitutes the discovery of the up quark , down quark , and strange quark . </Td> </Tr> <Tr> <Td> </Td> <Td> J / ψ meson discovered by groups headed by Burton Richter and Samuel Ting , demonstrating the existence of the charm quark ( proposed by James Bjorken and Sheldon Lee Glashow in 1964 ) </Td> </Tr> <Tr> <Td> </Td> <Td> Tau discovered by a group headed by Martin Perl </Td> </Tr> <Tr> <Td> 1977 </Td> <Td> Upsilon meson discovered at Fermilab , demonstrating the existence of the bottom quark ( proposed by Kobayashi and Maskawa in 1973 ) </Td> </Tr> <Tr> <Td> 1979 </Td> <Td> Gluon observed indirectly in three - jet events at DESY </Td> </Tr> <Tr> <Td> </Td> <Td> W and Z bosons discovered by
<Table> <Tr> <Th> Time </Th> <Th> Event </Th> </Tr> <Tr> <Td> 1800 </Td> <Td> William Herschel discovers `` heat rays '' </Td> </Tr> <Tr> <Td> 1801 </Td> <Td> Johann Wilhelm Ritter made the hallmark observation that invisible rays just beyond the violet end of the visible spectrum were especially effective at lightening silver chloride - soaked paper . He called them `` oxidizing rays '' to emphasize chemical reactivity and to distinguish them from `` heat rays '' at the other end of the invisible spectrum ( both of which were later determined to be photons ) . The more general term `` chemical rays '' was adopted shortly thereafter to describe the oxidizing rays , and it remained popular throughout the 19th century . The terms chemical and heat rays were eventually dropped in favor of ultraviolet and infrared radiation , respectively . </Td> </Tr> <Tr> <Td> 1895 </Td> <Td> Discovery of the ultraviolet radiation below 200 nm , named vacuum ultraviolet ( later identified as photons ) because it is strongly absorbed by air , by the German physicist Victor Schumann </Td> </Tr> <Tr> <Td> 1895 </Td> <Td> X-ray produced by Wilhelm Röntgen ( later identified as photons ) </Td> </Tr> <Tr> <Td> 1897 </Td> <Td> Electron discovered by J.J. Thomson </Td> </Tr> <Tr> <Td> 1899 </Td> <Td> Alpha particle discovered by Ernest Rutherford in uranium radiation </Td> </Tr> <Tr> <Td> 1900 </Td> <Td> Gamma ray ( a high - energy photon ) discovered by Paul Villard in uranium decay </Td> </Tr> <Tr> <Td> 1911 </Td> <Td> Atomic nucleus identified by Ernest Rutherford , based on scattering observed by Hans Geiger and Ernest Marsden </Td> </Tr> <Tr> <Td> 1919 </Td> <Td> Proton discovered by Ernest Rutherford </Td> </Tr> <Tr> <Td> 1931 </Td> <Td> Deuteron discovered by Harold Urey ( predicted by Rutherford in 1920 ) </Td> </Tr> <Tr> <Td> 1932 </Td> <Td> Neutron discovered by James Chadwick ( predicted by Rutherford in 1920 ) Main article : Discovery of the neutron </Td> </Tr> <Tr> <Td> 1932 </Td> <Td> Antielectron ( or positron ) , the first antiparticle , discovered by Carl D. Anderson ( proposed by Paul Dirac in 1927 and by Ettore Majorana in 1928 ) </Td> </Tr> <Tr> <Td> 1937 </Td> <Td> Muon ( or mu lepton ) discovered by Seth Neddermeyer , Carl D. Anderson , J.C. Street , and E.C. Stevenson , using cloud chamber measurements of cosmic rays ( it was mistaken for the pion until 1947 ) </Td> </Tr> <Tr> <Td> 1947 </Td> <Td> Pion ( or pi meson ) discovered by C.F. Powell 's group , including César Lattes ( first author ) and Giuseppe Occhialini ( predicted by Hideki Yukawa in 1935 ) </Td> </Tr> <Tr> <Td> 1947 </Td> <Td> Kaon ( or K meson ) , the first strange particle , discovered by George Dixon Rochester and Clifford Charles Butler </Td> </Tr> <Tr> <Td> 1950 </Td> <Td> Λ ( or lamda baryon ) discovered during a study of cosmic - ray interactions </Td> </Tr> <Tr> <Td> 1955 </Td> <Td> Antiproton discovered by Owen Chamberlain , Emilio Segrè , Clyde Wiegand , and Thomas Ypsilantis </Td> </Tr> <Tr> <Td> 1956 </Td> <Td> Electron antineutrino detected by Frederick Reines and Clyde Cowan ( proposed by Wolfgang Pauli in 1930 to explain the apparent violation of conservation of energy in beta decay ) At the time it was simply referred to as neutrino since there was only one known neutrino . </Td> </Tr> <Tr> <Td> 1962 </Td> <Td> Muon neutrino ( or mu neutrino ) shown to be distinct from the electron neutrino by a group headed by Leon Lederman </Td> </Tr> <Tr> <Td> 1964 </Td> <Td> Xi baryon discovery at Brookhaven National Laboratory </Td> </Tr> <Tr> <Td> 1969 </Td> <Td> Partons ( internal constituents of hadrons ) observed in deep inelastic scattering experiments between protons and electrons at SLAC ; this was eventually associated with the quark model ( predicted by Murray Gell - Mann and George Zweig in 1964 ) and thus constitutes the discovery of the up quark , down quark , and strange quark . </Td> </Tr> <Tr> <Td> </Td> <Td> J / ψ meson discovered by groups headed by Burton Richter and Samuel Ting , demonstrating the existence of the charm quark ( proposed by James Bjorken and Sheldon Lee Glashow in 1964 ) </Td> </Tr> <Tr> <Td> </Td> <Td> Tau discovered by a group headed by Martin Perl </Td> </Tr> <Tr> <Td> 1977 </Td> <Td> Upsilon meson discovered at Fermilab , demonstrating the existence of the bottom quark ( proposed by Kobayashi and Maskawa in 1973 ) </Td> </Tr> <Tr> <Td> 1979 </Td> <Td> Gluon observed indirectly in three - jet events at DESY </Td> </Tr> <Tr> <Td> </Td> <Td> W and Z bosons discovered by
who discovered the subatomic particles of an atom
who discovered the subatomic particles of an atom
J.J. Thomson Ernest Rutherford James Chadwick
J.J. Thomson Ernest Rutherford James Chadwick