Assertion: electron | /r/HasProperty | discovered by j j thompson
Facets:
value: in 1897
type: TEMPORAL
Source sentences:
text: About century ago the proton (first thought of by Rutherford in 1911) the neutron (the properties of neutrons and protons were defined by James Chadwick in 1932) and electron (discovered by J J Thompson in 1897) were thought to be the fundamental particles.
text: It was discovered by J. J.Thomson in 1897.