cathode rays

(noun)

Streams of electrons observed in vacuum tubes

Related Terms

Examples of cathode rays in the following topics:

  • Cathode Rays

    • Electrons were first discovered as the constituents of cathode rays.
    • Cathode rays are so named because they are emitted by the negative electrode, or cathode, in a vacuum tube.
    • These were the cathode rays.
    • Eugene Goldstein named them cathode rays.
    • It was used in discovery of cathode rays.

  • Particle Accelerator

    • A small-scale example of this class is the cathode ray tube in an ordinary, old television set.

  • Modes of Radioactive Decay

    • Alpha particles carry a positive charge, beta particles carry a negative charge, and gamma rays are neutral.
    • Other experiments showed the similarity between classical beta radiation and cathode rays; they are both streams of electrons.
    • Likewise, gamma radiation and X-rays were found to be similar high-energy electromagnetic radiation.
    • Some decay reactions release energy in the form of electromagnetic waves called gamma rays.
    • Gamma rays can only be reduced by much more substantial mass, such as a very thick layer of lead.

  • Millikan's Oil Drop Experiment

    • Alternatively, charge could be induced by including an ionizing radiation source (such as an X-ray tube).
    • Experimenting with cathode rays in 1897, J.

  • Voltaic Cells

    • The cathode is the electrode where reduction takes place.
    • The anode will undergo oxidation and the cathode will undergo reduction.
    • At the cathode, the metal ion in the solution will accept one or more electrons from the cathode, and the ion's oxidation state will reduce to 0.
    • This forms a solid metal that deposits on the cathode.
    • Copper readily oxidizes zinc; the anode is zinc and the cathode is copper.

  • Electrochemical Cell Notation

    • .), the anode, the cathode, and the electrode components are all described in this unique shorthand.
    • Recall that oxidation takes place at the anode and reduction takes place at the cathode.
    • When the anode and cathode are connected by a wire, electrons flow from anode to cathode.
    • In the reaction, the silver ion is reduced by gaining an electron, and solid Ag is the cathode.
    • The anode half-cell is described first; the cathode half-cell follows.

  • The Lithium-Ion Battery

    • The three participants in the electrochemical reactions in a lithium-ion battery are the anode, the cathode, and the electrolyte.
    • Both the anode, which is a lithium-containing compound, and the cathode, which is a carbon-containing compound, are materials into which lithium ions can migrate.
    • When a lithium-based cell is discharging, the positive lithium ion is extracted from the cathode and inserted into the anode, releasing stored energy in the process.
    • The most commercially popular cathode material is graphite.
    • In a lithium-ion battery, the lithium ions are transported to and from the cathode or anode.

  • Electrolysis of Water

    • Multiplying the cathode reaction by 2, in order to match the number of electrons transferred, results in this net equation, after OH- and H+ ions combine to form water:
    • Hydrogen will appear at the cathode, the negatively charged electrode, where electrons enter the water, and oxygen will appear at the anode, the positively charged electrode.

  • Determining Atomic Structures by X-Ray Crystallography

    • X-ray crystallography is a method of determining the arrangement of atoms within molecules.
    • X-ray crystallography is a method for determining the arrangement of atoms within a crystal structure.
    • The crystal is typically rotated with respect to different axes and shot again with X-rays, so that diffraction patterns from all angles of the X-rays hitting the crystal are recorded.
    • When bombarded with x-ray radiation, crystals exhibit a characteristic diffraction pattern.
    • An X-ray diffraction pattern of a crystallized protein molecule.

  • Electrolytic Properties

    • Another reaction occurs at the anode, producing electrons that are eventually transferred to the cathode.
    • As a result, a negative charge cloud develops in the electrolyte around the cathode, and a positive charge develops around the anode.
    • For example, in a solution of ordinary table salt (sodium chloride, NaCl) in water, the cathode reaction will be:
    • Two mnemonics for remembering that reduction happens at the cathode and oxidation at the anode are: "Red Cat" (reduction - cathode) and "An Ox" (anode - oxidation).
    • For example, p-Benzoquinone can be reduced to hydroquinone at the cathode: