Question: who discovered the subatomic particles of an atom
Answer: 1895 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 1895 X-ray produced by Wilhelm Röntgen ( later identified as photons ) 1897 Electron discovered by J.J. Thomson 1899 Alpha particle discovered by Ernest Rutherford in uranium radiation 1900 Gamma ray ( a high - energy photon ) discovered by Paul Villard in uranium decay 1911 Atomic nucleus identified by Ernest Rutherford , based on scattering observed by Hans Geiger and Ernest Marsden 1919 Proton discovered by Ernest Rutherford 1931 Deuteron discovered by Harold Urey ( predicted by Rutherford in 1920 ) 1932 Neutron discovered by James Chadwick ( predicted by Rutherford in 1920 ) Main article : Discovery of the neutro