Original: Sir Joseph John “J. J.” Thomson, OM, FRS (18 December 1856   30 August 1940) was a British physicist and Nobel laureate, credited for the discovery of the electron and of isotopes, and the invention of the mass spectrometer.
Simplified: Sir Joseph John "J.J." Thomson, OM, FRS (18 December 1856   30 August 1940) was a British physicist and Nobel laureate, that discovered the electron and isotopes, and invented the mass spectrometer.