JJ Thomson's Amazing Discovery


1. In 1904 Thomson suggested a model of the atom as a sphere of positive matter in which electrons are positioned by electrostatic forces.

2. His assistant, Francis Aston, developed Thomson's instrument further and with the improved version was able to discover isotopes—atoms of the same element with different atomic weights—in a large number of nonradioactive elements.

3. In 1897 he showed that cathode rays, radiation emitted in a low pressure glass tube when a voltage is applied between two metal plates, consist of particles, electrons, that carry electricity. Thomson also concluded that electrons were part of the atom.

4. Thomson's early interest in atomic structure was reflected in his Treatise on the Motion of Vortex Rings which won him the Adams Prize in 1884.

5. His book, Conduction of Electricity through Gases, published in 1903 was described by Lord Rayleigh as a review of "Thomson's great days at the Cavendish Laboratory".

6. He discovered a method for separating different kinds of atoms and molecules by the use of positive rays, an idea developed by Aston, Dempster and others towards the discovery of many isotopes.

Attended Owens collage, Manchester, recommended to trinity, Cambridge.

Born in cheethem hill, Manchester, UK on dec. 18, 1856

Died august 30, 1940 Cambridge, uk

Nobel prize in physics

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