Jj thomson what was his experiment

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.

Later he estimated the value of the charge itself. In Thomson suggested a model of the atom as a sphere of positive matter in which electrons are positioned by electrostatic forces. His efforts to estimate the number of electrons in an atom from measurements of the scattering of light, X, beta, and gamma rays initiated the research trajectory along which his student Ernest Rutherford moved.

Here his techniques led to the development of the mass spectrograph. Thomson left and Ernest Rutherford in the s. Ironically, Thomson—great scientist and physics mentor—became a physicist by default. His father intended him to be an engineer, which in those days required an apprenticeship, but his family could not raise the necessary fee.

He collected data using a variety of tubes and using different gases. Thomson experimenting, in the Cavendish Lab. Just as Emil Wiechert had reported earlier that year, the mass-to-charge ratio for cathode rays turned out to be far smaller than that of a charged hydrogen atom--more than one thousand times smaller. Either the cathode rays carried an enormous charge as compared with a charged atom , or else they were amazingly light relative to their charge. Experimenting on how cathode rays penetrate gases, he showed that if cathode rays were particles they had to have a mass very much smaller than the mass of any atom.

The proof was far from conclusive. But experiments by others in the next two years yielded an independent measurement of the value of the charge e and confirmed this remarkable conclusion.

One of the tubes used in Thomson's third experiment. Table of Contents: Exhibit Home J. He discovered that the ratio was the same regardless of what type of gas was used, which led him to conclude that the particles that made up the gases were universal. Thomson determined that all matter is made up of tiny particles that are much smaller than atoms. He originally called these particles 'corpuscles,' although they are now called electrons. This discovery upended the prevailing theory that the atom was the smallest fundamental unit.

In , Thomson began studying positively charged ions, or positive rays. This led to one of his other famous discoveries in when he channeled a stream of ionized neon through a magnetic and an electric field and used deflection techniques to measure the charge to mass ratio.

In doing so, he discovered that neon was composed of two different kinds of atoms, and proved the existence of isotopes in a stable element. This was the first use of mass spectrometry. Thomson married Rose Paget, one of his students, in They had one daughter, Joan, and one son, George Paget Thomson, who went on to become a physicist and win a Nobel Prize of his own.

Thomson published 13 books and more than papers in his lifetime. He left research in to become Master of Trinity College. We strive for accuracy and fairness. If you see something that doesn't look right, contact us!