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Sir Joseph John Thomson (18 December 1856 ... Thomson constructed a Crookes tube with an electrometer set to one side, out of the direct path of the cathode rays ...
Crookes X-ray tube from around 1910 Another Crookes x-ray tube. The device attached to the neck of the tube (right) is an "osmotic softener". When the voltage applied to a Crookes tube is high enough, around 5,000 volts or greater, [16] it can accelerate the electrons to a high enough velocity to create X-rays when they hit the anode or the glass wall of the tube.
It remained for Sir J. J. Thomson to expound on the subatomic nature of cathode rays (consisting of streams of negative electrons [27]). Nevertheless, Crookes's experimental work in this field was the foundation of discoveries which eventually changed the whole of chemistry and physics.
Crookes insisted it was a particle, while Hertz maintained it was a wave. The debate was resolved when an electric field was used to deflect the rays by J. J. Thomson. This was evidence that the beams were composed of particles because scientists knew it was impossible to deflect electromagnetic waves with an electric field.
In 1897, J. J. Thomson succeeded in measuring the mass-to-charge ratio of cathode rays, showing that they consisted of negatively charged particles smaller than atoms, the first "subatomic particles", which had already been named electrons by Irish physicist George Johnstone Stoney in 1891.
Atoms were thought to be the smallest possible division of matter until 1899 when J. J. Thomson discovered the electron through his work on cathode rays. [37]: 86 [5]: 364 A Crookes tube is a sealed glass container in which two electrodes are separated by a vacuum.
Ionized matter was first identified in a discharge tube (or Crookes tube), and so described by Sir William Crookes in 1879 (he called it "radiant matter"). [5] The nature of the Crookes tube " cathode ray " matter was subsequently identified by English physicist Sir J.J. Thomson in 1897, [ 6 ] and dubbed "plasma" by Irving Langmuir in 1928, [ 7 ...
However, as J. J. Thomson explained in 1897, Hertz placed the deflecting electrodes in a highly-conductive area of the tube, resulting in a strong screening effect close to their surface. [ 35 ] The German-born British physicist Arthur Schuster expanded upon Crookes's experiments by placing metal plates parallel to the cathode rays and applying ...