09-19-2021-0834 - Sir Joseph John Thomson OM PRS 1856 1940

Sir Joseph John Thomson OM PRS^[1] (18 December 1856 – 30 August 1940) was a British physicist and Nobel Laureate in Physics, credited with the discovery of the electron, the first subatomic particle to be discovered.

In 1897, Thomson showed that cathode rays were composed of previously unknown negatively charged particles (now called electrons), which he calculated must have bodies much smaller than atoms and a very large charge-to-mass ratio.^[2] Thomson is also credited with finding the first evidence for isotopes of a stable (non-radioactive) element in 1913, as part of his exploration into the composition of canal rays (positive ions). His experiments to determine the nature of positively charged particles, with Francis William Aston, were the first use of mass spectrometry and led to the development of the mass spectrograph.^[2][3]

Thomson was awarded the 1906 Nobel Prize in Physics for his work on the conduction of electricity in gases.^[4]

Sir J. J. Thomson OM PRS
42nd President of the Royal Society
In office 1915–1920
Preceded by	William Crookes
Succeeded by	Charles Scott Sherrington
Master of Trinity College, Cambridge
In office 1918–1940
Preceded by	Henry Montagu Butler
Succeeded by	George Macaulay Trevelyan
Personal details
Born	Joseph John Thomson 18 December 1856 Cheetham Hill, Manchester, England
Died	30 August 1940 (aged 83) Cambridge, England
Citizenship	British
Nationality	English
Children	George Paget Thomson, Joan Paget Thomson
Alma mater	Owens College (now the University of Manchester) Trinity College, Cambridge (BA)
Signature
Known for	Plum pudding model Discovery of electron Discovery of isotopes Mass spectrometer invention Electromagnetic mass First m/e measurement Proposed first waveguide Gibbs–Thomson equation Thomson scattering Thomson problem Coining term 'delta ray' Coining term 'epsilon radiation' Thomson (unit)
Awards	Smith's Prize (1880) Royal Medal (1894) Hughes Medal (1902) Nobel Prize in Physics (1906) Elliott Cresson Medal (1910) Copley Medal (1914) Albert Medal (1915) Franklin Medal (1922) Faraday Medal (1925) Dalton Medal (1931)
Scientific career
Fields	Physics
Institutions	Trinity College, Cambridge
Academic advisors	John Strutt (Rayleigh) Edward John Routh
Notable students	Charles Glover Barkla Charles T. R. Wilson Ernest Rutherford Francis William Aston John Townsend J. Robert Oppenheimer Owen Richardson William Henry Bragg H. Stanley Allen John Zeleny Daniel Frost Comstock Max Born T. H. Laby Paul Langevin Balthasar van der Pol Geoffrey Ingram Taylor Niels Bohr George Paget Thomson Debendra Mohan Bose Lawrence Bragg

https://en.wikipedia.org/wiki/J._J._Thomson