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The Discovery of the Electron

explanatory Essay
999 words
999 words
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There are many different experiments which can give varying intelligence about the makeup of matter, in different ways and with different conclusions. In this instance I will be looking at the discovery of the electron, how our understanding of it has changed over the years, and measure how it has contributed to where we are today.

Joseph John Thomson (J. J. Thomson, 1856 - 1940) is widely recognized as the discoverer of the electron. Thomson was a Professor of Experimental Physics at Cambridge University, and Director of its Cavendish Laboratory, from 1884 until 1919. It is here where his most well-known, varied and comprehensive work, in the field of conduction of electricity within gases, was undertaken. In 1897 Thompson made an announcement stating that cathode rays were negatively charged particles which he referred to as 'corpuscles', and pronounced that they had a mass some 1,000 times less than a hydrogen atom. Thompson proposed that corpuscles were the items from which atoms were constructed, and concluded that cathode rays possessed a new state by merit of their ability to carry further than the ordinary gaseous state. This was proposed as a state in which all matter is derived from different sources, such as hydrogen or oxygen. This implied that the original discovery was different to the one Thompson now proposed, that the particles were a fundamental element of all matter.

Thompson’s experiment used a pair of plates as electrodes in a glass tube, between which a high voltage potential was applied. When the pressure of the gas in the tube became very low (less than 0.1 atmospheres), an electric discharge took place. This was referred to as vacuum discharge. When the gas pressure in the tube was further reduce...

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...ituation. We would lack an understanding of the anatomy of atoms, and how they are made up of a nucleus with surrounding electrons, and the influence they have on the world around us, and how it works. The importance of electrons would not be appreciated, nor their relevance to experiments on the theory of matter.

Works Cited

1) Anthony Carpi, Ph.D. "Atomic Theory I: The Early Days," Visionlearning Vol. CHE-1 (2), 2003.

2) J.J. Thomson (1897), Cathode rays, Philosophical Magazine, 44, 293 — The classic measurement of the electron mass and charge

3) Thomson, George Paget. (1964) J.J. Thomson: Discoverer of the Electron. Great Britain: Thomas Nelson & Sons, Ltd.

4) Navarro, Jaume, 2005, "Thomson on the Nature of Matter: Corpuscles and the Continuum," Centaurus 47(4): 259-82.

5) Nobel Lectures, Chemistry 1901-1921, Elsevier Publishing Company, Amsterdam, 1966

In this essay, the author

  • Explains that there are many different experiments which can give varying intelligence about the makeup of matter, in different ways and with different conclusions. in this instance, they will be looking at the discovery of the electron.
  • Explains that joseph john thomson is widely recognized as the discoverer of the electron. he was professor of experimental physics at cambridge university, and director of its cavendish laboratory.
  • Describes thompson's experiment using plates as electrodes in a glass tube. when the pressure of the gas in the tube became very low, an electric discharge took place.
  • Explains that thomson assumed that the cathode rays emanating from the negative electrode were a collection of particles possessing negative charges.
  • Explains that thomson's first painstaking experiments and adventurous hypotheses were substantiated by crucial experimental and theoretical work.
  • Explains how thomson changed the modern view of the atom in 1897 when he discovered the electron.
  • Explains that ernest rutherford, a chemist from new zealand, performed experiments with radioactive alpha particles, but it was not clear what they comprised.
  • Explains that rutherford's theory of an atom resembled a tiny solar system with the positively charged nucleus always at the centre.
  • Opines that if thomson and rutherford's experiments had not been carried out, we wouldn't be in our current situation.
  • Cites anthony carpi, ph.d., j.j. thomson, george paget, and jaume navarro.
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