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Cathode rays are now usually called electron beams. The technology of manipulating electron beams pioneered in these early tubes was applied practically in the design of vacuum tubes, particularly in the invention of the cathode-ray tube (CRT) by Ferdinand Braun in 1897, which was used in television sets and oscilloscopes.
In a galvanic cell, the cathode is the positive terminal or pole which accepts electrons flowing from the external part of an electrical circuit. However, in an electrolytic cell, the cathode is the wire or plate having excess negative charge, so named because positively charged cations tend to move towards it. Contrast anode. cathode ray cation
The first commercially made electronic TV sets with cathode-ray tubes were manufactured by Telefunken in Germany in 1934. [32] [33] In 1947, the cathode-ray tube amusement device, the earliest known interactive electronic game as well as the first to incorporate a cathode-ray tube screen, was created. [34]
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.
In chemistry, a cathode is the electrode of an electrochemical cell at which reduction occurs. The cathode can be negative like when the cell is electrolytic (where electrical energy provided to the cell is being used for decomposing chemical compounds); or positive as when the cell is galvanic (where chemical reactions are used for generating ...
Thermionic vacuum tubes emit electrons from a hot cathode into an enclosed vacuum and may steer those emitted electrons with applied voltage. The hot cathode can be a metal filament, a coated metal filament, or a separate structure of metal or carbides or borides of transition metals.
Electrophoresis is the basis for analytical techniques used in biochemistry and molecular biology to separate particles, molecules, or ions by size, charge, or binding affinity, either freely or through a supportive medium using a one-directional flow of electrical charge. [10] It is used extensively in DNA, RNA and protein analysis. [11]
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...