J. J. Thomson

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.

J. J. Thomson
42nd President of the Royal Society
In office
Preceded byWilliam Crookes
Succeeded byCharles Scott Sherrington
Master of Trinity College, Cambridge
In office
Preceded byHenry Montagu Butler
Succeeded byGeorge Macaulay Trevelyan
Personal details
Joseph John Thomson

(1856-12-18)18 December 1856
Cheetham Hill, Manchester, England
Died30 August 1940(1940-08-30) (aged 83)
Cambridge, England
ChildrenGeorge Paget Thomson, Joan Paget Thomson
Alma materOwens College (now the University of Manchester)
Trinity College, Cambridge (BA)
Known forPlum 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)
AwardsSmith'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
InstitutionsTrinity College, Cambridge
Academic advisorsJohn Strutt (Rayleigh)
Edward John Routh
Notable studentsCharles 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
External video
The Early Life of J.J. Thomson: Computational Chemistry and Gas Discharge Experiments

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]

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