FACTOID # 2: Puerto Rico has roughly the same gross state product as Montana, Wyoming and North Dakota combined.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Electrode" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Electrode

An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte or a vacuum). The word was coined by the scientist Michael Faraday from the Greek words elektron (meaning amber, from which the word electricity is derived) and hodos, a way.[1] The word electrode has multiple meanings: In electronics, an electrode is a conductor used to make contact with a nonmetallic part of a circuit. ... In science and engineering, conductors, such as copper or aluminum, are materials with atoms having loosely held valence electrons. ... An electronic circuit is an electrical circuit that also contains active electronic devices such as transistors or vacuum tubes. ... A semiconductor is a solid whose electrical conductivity is in between that of a conductor and that of an insulator, and can be controlled over a wide range, either permanently or dynamically. ... An electrolyte is a substance containing free ions that behaves as an electrically conductive medium. ... Look up Vacuum in Wiktionary, the free dictionary. ... Michael Faraday, FRS (September 22, 1791 – August 25, 1867) was an English chemist and physicist (or natural philosopher, in the terminology of that time) who contributed to the fields of electromagnetism and electrochemistry. ... For other uses, see Amber (disambiguation). ... Electricity (from New Latin ēlectricus, amberlike) is a general term for a variety of phenomena resulting from the presence and flow of electric charge. ...

Contents

Anode and cathode in electrochemical cells

Scheme of a discharging galvanic cell

An electrode in an electrochemical cell is referred to as either an anode or a cathode, words that were also coined by Faraday. The anode is now defined as the electrode at which electrons leave the cell and oxidation occurs, and the cathode as the electrode at which electrons enter the cell and reduction occurs. Each electrode may become either the anode or the cathode depending on the voltage applied to the cell. A bipolar electrode is an electrode that functions as the anode of one cell and the cathode of another cell. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... The Galvanic cell, named after Luigi Galvani, consists of two different metals connected by a salt bridge or a porous disk between the individual half-cells. ... A demonstration electrochemical cell setup resembling the Daniell cell. ... Diagram of a zinc anode in a galvanic cell. ... Diagram of a copper cathode in a Daniells cell. ... The most fundamental reactions in chemistry are the redox processes. ... Illustration of a redox reaction Redox (shorthand for oxidation/reduction reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ...


Primary cell

A primary cell is special type of electrochemical cell in which the reaction cannot be reversed, and the identities of the anode and cathode are therefore fixed. The anode is always the negative electrode. The cell can be discharged but not recharged. A primary cell is any kind of electrolytic cell in which the electrochemical reaction of interest is not reversible. ...


Secondary cell

The case in an electrolytic cell. When the cell is being discharged, it behaves like a primary or voltaic cell, with the anode as the negative electrode and the cathode as the positive. // Electrolytic cells are composed of a vessel used to do electrolysis, containing electrolyte, usually a solution of water or other solvents capable of dissolving various ions into solution, and a cathode and anode. ... Voltaic cell can connote: Galvanic cell Voltaic pile see also: battery (electricity), fuel cell This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...


Other anodes and cathodes

In a vacuum tube or a semiconductor having polarity (diodes, electrolytic capacitors) the anode is the positive (+) electrode and the cathode the negative (−). The electrons enter the device through the cathode and exit the device through the anode. Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ... A semiconductor is a solid whose electrical conductivity is in between that of a conductor and that of an insulator, and can be controlled over a wide range, either permanently or dynamically. ... Closeup of the image below, showing the square shaped semiconductor crystal various semiconductor diodes, below a bridge rectifier Structure of a vacuum tube diode In electronics, a diode is a two-terminal component, almost always one that has electrical properties which vary depending on the direction of flow of charge... An electrolyte is a substance which dissociates free ions when dissolved (or molten), to produce an electrically conductive medium. ...


In a three-electrode cell, a counter electrode, also called an auxiliary electrode, is used only to make a connection to the electrolyte so that a current can be applied to the working electrode. The counter electrode is usually made of an inert material, such as a noble metal or graphite, to keep it from dissolving. Noble metals are metals that are resistant to corrosion or oxidation, unlike most base metals. ... For other uses, see Graphite (disambiguation). ...


Welding electrodes

In arc welding an electrode is used to conduct current through a workpiece to fuse two pieces together. Depending upon the process, the electrode is either consumable, in the case of gas metal arc welding or shielded metal arc welding, or non-consumable, such as in gas tungsten arc welding. For a direct current system the weld rod or stick may be a cathode for a filling type weld or an anode for other welding processes. For an alternating current arc welder the welding electrode would not be considered an anode or cathode. To learn more about tungsten electrodes and their preparation, visit http://www.diamondground.com/downloads.html for free guides. Manual Metal Arc welding, also known as stick or MMA welding is one of the most common forms of welding. ... Gas metal arc welding Gas metal arc welding (GMAW), sometimes referred to by its subtypes, metal inert gas (MIG) welding or metal active gas (MAG) welding, is a semi-automatic or automatic arc welding process in which a continuous and consumable wire electrode and a shielding gas are fed through... Shielded metal arc welding Shielded metal arc welding (SMAW), also known as manual metal arc (MMA) welding or informally as stick welding, is a manual arc welding process that uses a consumable electrode coated in flux to lay the weld. ... Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a nonconsumable tungsten electrode to produce the weld. ...


Alternating current electrodes

For electrical systems which use alternating current the electrodes are the connections from the circuitry to the object to be acted upon by the electrical current but are not designated anode or cathode since the direction of flow of the electrons changes periodically, usually many times per second. City lights viewed in a motion blurred exposure. ... City lights viewed in a motion blurred exposure. ... This article is about the SI unit of frequency. ...


Uses of electrodes

“EEG” redirects here. ... “QRS” redirects here. ... Electroconvulsive therapy (ECT), also known as electroshock, is a controversial psychiatric treatment in which seizures are induced with electricity for therapeutic effect. ... This article or section does not adequately cite its references or sources. ... Current Clamp is a common technique in electrophysiology. ... The electric chair is an execution method in which the person being put to death is strapped to a chair and electrocuted through electrodes placed on the body. ... Electroplating is the process of using Davd lloyd current to coat an electrically conductive object with a relatively thin layer of metal. ... Manual Metal Arc welding, also known as stick or MMA welding is one of the most common forms of welding. ... Aluminium anodes mounted on a steel jacket structure Cathodic protection (CP) is a technique to control the corrosion of a metal surface by making that surface the cathode of an electrochemical cell. ... There are several meanings of the term Grounding: Grounding is also used to describe the connection of part of an electrical circuit to an electrical ground. ... This article is about the chemical process. ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ...

See also

The working electrode, is the electrode in an electrochemical system on which the reaction of interest is occurring. ... Reference electrode is an electrode which has a stable and well-known electrode potential. ... Symbols representing a single Cell (top) and Battery (bottom), used in circuit diagrams. ... Illustration of a redox reaction Redox (shorthand for oxidation/reduction reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. ... Aluminium anodes mounted on a steel jacket structure Cathodic protection (CP) is a technique to control the corrosion of a metal surface by making that surface the cathode of an electrochemical cell. ... The Galvanic cell, named after Luigi Galvani, consists of two different metals connected by a salt bridge or a porous disk between the individual half-cells. ... An anion is an ion with negative charge. ... This article is about the electrically charged particle. ... For other uses, see Electron (disambiguation). ... For the following two reasons the electron hole was introduced into calculations: If an electron is excited into higher state it leaves a hole in its old state. ... An electrolyte is a substance containing free ions that behaves as an electrically conductive medium. ... An electron microscope is a type of microscope that uses electrons to illuminate and create an image of a specimen. ... Noryl resin is a plastic developed by General Electric. ...

References

  1. ^ Michael Faraday, "On Electrical Decomposition", Philosophical Transactions of the Royal Society, 1834 (in which Faraday coins the words electrode, anode, cathode, anion, cation, electrolyte, electrolyze).
Wikimedia Commons has media related to:
Electrodes

  Results from FactBites:
 
Electrode - Wikipedia, the free encyclopedia (542 words)
A bipolar electrode is an electrode that functions as the anode of one cell and the cathode of another cell.
In a vacuum tube or a semiconductor having polarity (diodes, electrolytic capacitors) the anode is the positive (+) electrode and the cathode the negative (−).
Depending upon the process, the electrode is either consumable, in the case of gas metal arc welding or shielded metal arc welding, or non-consumable, such as in gas tungsten arc welding.
Electrochemistry Dictionary (11199 words)
An electrode that is shared by two series-coupled electrochemical cells in such a way that one side of the (usually planar) electrode acts as an anode in one cell and the other side acts as a cathode in the other cell.
In case of an electrode reaction, the electrode itself is considered one of the "reactants." An electrode reaction is a heterogeneous charge-transfer reaction.
An electrode reaction is considered to be under “diffusion control” when the overall rate of the reaction is is controlled by the rate of the diffusion of the reactants to the electrode surface rather than the rate of the reaction itself.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m