Sir PERSON@1 , ORGANIZATION@1 , FRS -LRB- NUMBER@1 December NUMBER@2 NUMBER@3 August NUMBER@4 -RRB- was a MISC@1 physicist and MISC@2 laureate , credited for the discovery of the electron and of isotopes , and the invention of the mass spectrometer .

Sir PERSON@2 , OM , FRS -LRB- NUMBER@1 December NUMBER@2 NUMBER@3 August NUMBER@4 -RRB- was a MISC@1 physicist and MISC@2 laureate , that discovered the electron and isotopes , and invented the mass spectrometer .
