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Sir William Crookes (/ k r ʊ k s /; 17 June 1832 – 4 April 1919) was an English chemist and physicist who attended the Royal College of Chemistry, [1] now part of Imperial College London, and worked on spectroscopy. He was a pioneer of vacuum tubes, inventing the Crookes tube, which was made in 1875. This was a foundational discovery that ...
The spinthariscope was invented by William Crookes in 1903. [4] [5] While observing the apparently uniform fluorescence on a zinc sulfide screen created by the radioactive emissions (mostly alpha radiation) of a sample of radium bromide, he spilled some of the sample, and, owing to its extreme rarity and cost, he was eager to find and recover it. [6]
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.
The first device which used a scintillator was built in 1903 by Sir William Crookes and used a ZnS screen. [2] [3] The scintillations produced by the screen were visible to the naked eye if viewed by a microscope in a darkened room; the device was known as a spinthariscope. The technique led to a number of important discoveries but was ...
During the 1870s, the English chemist and physicist Sir William Crookes developed the first cathode-ray tube to have a high vacuum inside. [36] He then showed in 1874 that the cathode rays can turn a small paddle wheel when placed in their path. Therefore, he concluded that the rays carried momentum.
Chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861, in residues of sulfuric acid production. Both used the newly developed method of flame spectroscopy, in which thallium produces a notable green spectral line. Thallium, from Greek θαλλός, thallós, meaning "green shoot" or "twig", was named by ...
William Crookes: Invented the Crookes tube. 1873: Willoughby Smith: Discovered the photoelectric effect in metals not in solution (i.e., selenium). 1873: James Clerk Maxwell: Published his theory of electromagnetism in which light was determined to be an electromagnetic wave (field) that could be propagated in a vacuum. 1877: Ludwig Boltzmann
This led to a series of atomic models with some quantum aspects, such as that of Arthur Erich Haas in 1910 [37]: 197 and the 1912 John William Nicholson atomic model with quantized angular momentum as h/2 π. [58] [59] The dynamical structure of these models was still classical, but in 1913, Bohr abandon the classical approach.