See Article History Alternative Title: Sir Joseph John Thomson J. Thomson, in full Sir Joseph John Thomson, born December 18,Cheetham Hill, near ManchesterEngland—died August 30,Cambridge, CambridgeshireEnglish physicist who helped revolutionize the knowledge of atomic structure by his discovery of the electron
His mother, Emma Swindells, came from a local textile family. His father, Joseph James Thomson, ran an antiquarian bookshop founded by a great-grandfather. He had a brother, Frederick Vernon Thomson, who was two years younger than he was.
Thomson was a reserved yet devout Anglican. In he was admitted to Owens College in Manchester now University of Manchester at the unusually young age of Thomson was known for his work as a mathematician, where he was recognized as an exceptional talent.
In he gave the Romanes Lecture in Oxford on "The atomic theory". In he became Master of Trinity CollegeCambridgewhere he remained until his death. One of his students was Ernest Rutherfordwho later succeeded him as Cavendish Professor of Physics.
He examined the electromagnetic theory of light of James Clerk Maxwellintroduced the concept of electromagnetic mass of a charged particleand demonstrated that a moving charged body would apparently increase in mass. Thomson also presented a series of six lectures at Yale University in Thomson in was the first to suggest that one of the fundamental units was more than 1, times smaller than an atom, suggesting the subatomic particle now known as the electron.
Thomson discovered this through his explorations on the properties of cathode rays. Thomson made his suggestion on 30 April following his discovery that cathode rays at the time known as Lenard rays could travel much further through air than expected for an atom-sized particle.
His experiments suggested not only that cathode rays were over 1, times lighter than the hydrogen atom, but also that their mass was the same in whichever type of atom they came from.
He concluded that the rays were composed of very light, negatively charged particles which were a universal building block of atoms.
By comparing the deflection of a beam of cathode rays by electric and magnetic fields he obtained more robust measurements of the mass-to-charge ratio that confirmed his previous estimates.
Thomson believed that the corpuscles emerged from the atoms of the trace gas inside his cathode ray tubes.
He thus concluded that atoms were divisible, and that the corpuscles were their building blocks. In Thomson suggested a model of the atom, hypothesizing that it was a sphere of positive matter within which electrostatic forces determined the positioning of the corpuscles. Inas part of his exploration into the composition of the streams of positively charged particles then known as canal raysThomson and his research assistant F.
Aston channelled a stream of neon ions through a magnetic and an electric field and measured its deflection by placing a photographic plate in its path.
Aston and by A. Magnetic deflection[ edit ] Thomson first investigated the magnetic deflection of cathode rays. Cathode rays were produced in the side tube on the left of the apparatus and passed through the anode into the main bell jarwhere they were deflected by a magnet.
Thomson detected their path by the fluorescence on a squared screen in the jar.
He found that whatever the material of the anode and the gas in the jar, the deflection of the rays was the same, suggesting that the rays were of the same form whatever their origin. Thomson demonstrated that cathode rays could be deflected by a magnetic field, and that their negative charge was not a separate phenomenon.
While supporters of the aetherial theory accepted the possibility that negatively charged particles are produced in Crookes tubes ,[ citation needed ] they believed that they are a mere by-product and that the cathode rays themselves are immaterial.
Thomson constructed a Crookes tube with an electrometer set to one side, out of the direct path of the cathode rays. Thomson could trace the path of the ray by observing the phosphorescent patch it created where it hit the surface of the tube.Joseph John Thomson was born in Manchester, England in Thomson was indeed a good scientist, but he did not know that at first.
He attended college at a time when science was finally getting recognized as an important subject (Morgan). Sir Joseph John Thomson OM PRS (18 December – 30 August ) was an English physicist and Nobel Laureate in Physics, credited with the discovery and identification of the electron; and with the discovery of the first subatomic particle.
Joseph John Thomson was, therefore, the first who identified subatomic particles, and arrived at important conclusions about these negatively charged particles: with the appliance that was built was the relationship between electric charge and mass of the electron.
Thomson, Sir Joseph John, –, English physicist. From to he was Cavendish professor of experimental physics at Cambridge. From to he was Cavendish professor of experimental physics at Cambridge.
The ashes of physicist Sir Joseph John Thomson lie in the nave of Westminster Abbey near the graves of Newton and Rutherford.. The interment took place during his funeral service held on 4th September The British physicist Joseph John (J.
J.) Thomson (–) performed a series of experiments in designed to study the nature of electric discharge in a high-vacuum cathode-ray tube, an area being investigated by many scientists at the time.