Talk:Anode

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Hey, most or all of the interior (section reference) hyperlinks in this article don't work. Please fix them and delete this. Thanks.

in the electrlytic process used to plate copper onto a material, the material is the cathode or anode 68.231.188.151 (talk) 01:09, 25 August 2009 (UTC)

Wrong. Try it at home. The Anode is sacrificial (oxidized);so, the metal to Be plated With (say, Copper) is the Anode. The Cathode is being reduced (more electrons); so the negative Cathode (say, Iron) Gets plated.68.231.188.151 (talk) 01:09, 25 August 2009 (UTC)

I concur. The anode is sacrificial. At the gas company we had the men bury sacrificial magnesium anodes to protect the pipelines.

Please don't call "current" "conventional current" because it makes it sound like it's a special case of current or that there is an unconventional current. The convention (naming) for current is opposite in direction of the flow of electrons because chemistry and electricity started their own naming conventions independently of each other.

— Preceding unsigned comment added by 67.247.194.226 (talk • contribs) 04:10, 15 December 2016 (UTC)

Anode/Cathode

I've seen in older texts the " " side being descibed as Anode (Say, Zn on a dry cell); and the "-" being the cathode (carbon rod. As said, the current appears to go from the " black" lead on the carbon rod ("-") to Zn case (" ") and, the red lead on a voltmeter.68.231.188.151 (talk) 01:23, 25 August 2009 (UTC)

You've got that backwards. If you've ever taken apart a dry cell, you know the "-" side is the zinc and the " " side is the carbon rod. 65.0.215.24 (talk) 10:11, 7 November 2009 (UTC)

Half points then as the zinc electrode (-ve) is the anode. 86.183.25.124 (talk) 18:23, 4 April 2011 (UTC)

may i request further investigation 129.205.208.41 (talk) 10:47, 5 March 2024 (UTC)

The part of the cathode ray tube is incorrect. The electrons flow off of the negnative terminal: http://electronics.howstuffworks.com/tv3.htm —Preceding unsigned comment added by 75.187.47.144 (talk) 01:10, 18 May 2008 (UTC)

Not a very good reference, because although they have the CRT the right way round (as does the article), that link has the battery the wrong way round (i.e. the anode is the negative pole of a battery).20.133.0.13 (talk) 12:05, 19 June 2008 (UTC)

Ok. As far as I can tell the Cathode-ray tube is a historical mishap, but I can't tell why. The Hall Effect (1879) unambiguously determined that electrons were the carriers of current, and the cathode ray tube was invented in 1897 (Thompson), so it's not clear to me why they would call the terminal where the electrons are coming out as the "cathode".

But, either way, the definition on this page (cathode = positive (conventional) current out (neg in), anode = positive in (neg out)) works for everything except for CRTs. Circuit diagrams (physics), electronics, galvonic cells (chemistry), electrolytic cells (chemistry), all seem to be fine with this definition. As for the CRTs, it would be nice if a historian could help fill us in on this, but you'll just have to chalk this up to a historical accident, because every page (including the wikipedia page on cahode rays/CRTs) say that the cathode is where the electrons current comes out. —Preceding unsigned comment added by 75.187.47.144 (talk) 01:55, 18 May 2008 (UTC)

again, the confusion is caused by the idea that electrons flow in the direction of standard electric current, they do not, they flow OPPOSITE standard electric current, the CRT diagram you quote is correct for standard current (i.e. electric feild current that can do 'work') while the electrons are released from the Cathode (either by heating 'thermionic' or by feild emission) and flow to the anode. jonathan888 - not currently signed in —Preceding unsigned comment added by 198.50.4.4 (talk) 02:53, 4 June 2008 (UTC) Jonathan888 (talk) 16:43, 5 June 2008 (UTC)

The direction of Electron flow goes Cathode to Anode (not within a battery but external circuitry to the battery or power source) . To put a meter on it and read a positive voltage the black lead would be placed on the cathode while the red lead is placed on the anode. —Preceding unsigned comment added by 74.173.238.147 (talk) 15:16, 11 June 2008 (UTC)

To add too all of this, the intro is a little fuzzy. Electricity moves in both directions, electrons (negative) flow one way, and holes (positive) flow the other. So, the first sentence: "An anode is an electrode through which electric current flows into a polarized electrical device." should say that Positive current flows into a polarized device at the annode, or that negative current (or, electrons) flows out. Otherwise, one might assume that the current flowing in is referring to electrons flowing in, which, is wrong. —Preceding unsigned comment added by 75.106.174.195 (talk) 04:26, 29 November 2008 (UTC)

Note that the Hall effect does NOT unambiguously show the current carriers are negative. Many metals, including iron, have a positive Hall coefficient. The charge carriers are holes. Even more, I suspect that Benjamin Franklin likely used iron wire for his experiments. Gah4 (talk) 09:12, 7 October 2024 (UTC)

Ceramic anodes

The United States Army Corps of Engineers (USACE) invented ceramic-coated anodes. http://www.erdc.usace.army.mil/pls/erdcpub/docs/erdc/images/ERDCFactSheet_Product_CeramicAnodes.pdf -- Frap (talk) 14:52, 2 July 2008 (UTC)

Current does not flow

The "substance" that flows in wires and electrolytes is not "current", it is "charge". Current is defined as a flux of charges, so, saying that "current flows" is like saying that "the flux flows", or calling "current" the substance that flows in a river, instead of "water". Devil Master (talk) 22:37, 31 January 2009 (UTC)

You will have a hard time convincing anybody to adopt that language. Even though you might convince them to concede that what you say is technically correct, when they go back to work and talk amongst themselves, electrical engineers are going to continue saying that current flows in electronic circuits. Ditto for experts in the field of hydrology, who all say that current flows in streams and rivers. 151.201.129.79 (talk) 13:52, 16 June 2024 (UTC)

Agree with 151.201.129.79. It is simply an idiom, just like a candidate is said to "run for office". It doesn't cause misunderstanding. We had a long argument about current "flowing" on Electric current and it didn't accomplish anything except waste a lot of good people's time. --Chetvorno^TALK 16:26, 16 June 2024 (UTC)

Zener anode/cathode naming convention

The main article section indicates that the "forward bias" condition should be used for zener diodes even though you may be using them in the reverse breakdown regime:

"Note electrode naming for diodes is always based on the direction of the forward current (that of the arrow, in which the current flows "most easily"), even for types such as zener diodes or solar cells where the current of interest is the reverse current."

This seems to contradict the statement in the diode section of the article that says: "The terms anode and cathode should not be applied to a zener diode, since it allows flow in either direction, depending on the polarity of the applied potential (i.e. voltage)"

The article should be consistent, or should admit that "industry" is inconsistent on this point (in my expereince) and caution the user to understand what convention is used by the manufacturer.

This whole thing on Zeners is worng; please correct it. Zeners conduct only Forward when their threshold voltage is reached; most semi conductor diodes technically only "conduct" in the reverse direction if rated reverse breakdown is exceed (Vr). This usually destroys it, though. Only Tunnel diodes normally conduct both ways.. Zeners, as all semiconductor diodes, have actual current (electron) flow through them Opposite the arrow symbol. Current flows "_" to " " Always In an electric/electronic circuit.68.231.188.151 (talk) 01:17, 25 August 2009 (UTC)

Douglas 137.78.179.51 (talk) 01:35, 29 May 2009 (UTC)

Anode diagram

A minor point of labelling convention but, I note the diagram of the anode has the Zn2 ion labelled as Zn 2. It should be labelled as Zn2 (http://en.wikipedia.org/wiki/Ion#Denoting_the_charged_state). Unfortunately SVG editing isn't within my repertoire of skills but it would be good if someone could correct this. GoddersUK (talk) 17:19, 16 April 2012 (UTC)

device not in use -> no anode

If I have a polarized electrical device which is not attached to a circuit, then no charge is flowing. Therefore, neither electrode is the anode, is that correct?

(I am just checking, as it's the logical conclusion of the definition on the page right now. It just seems a little bit strange to me that the battery on my shelf has no anode until I put it into use.) --Nanite (talk) 13:14, 12 September 2013 (UTC)

Yes you are right, no current means no defined function. Suppose you have an iron rod on the shelf. If you put it and a silver rod into a suitable electrolyte and connect the rods via an ammeter you can see the current direction. The (external) current will be from the silver rod to the iron rod. The iron rod will function as an anode. But if you use zinc instead of silver the current is reversed ie the iron rod is the cathode and the zinc piece will be the anode. But now if someone put an electrod on the shelf it is most likely designed for a specific purpose and there will be no missunderstanding if you call it an anode (or a cathode if that is the case). You mention battery — well is it a rechargeable one? Watch out, it may then be better to speak about the negative and the positive terminals. Stenallan (talk) 22:28, 9 April 2015 (UTC)

Thanks for the reply! (Sorry, I just noticed it now.) It's good to hear there is a logically consistent definition though there does seem to be misunderstanding out there. See discussions [1], [2]. It seems on the interenet there is a consensus about the correct meaning, but I am having trouble finding an authoritative source. The introduction of this article doesn't seem to cite any paper sources. --Nanite (talk) 10:36, 9 November 2015 (UTC)

Thank you Nanite for providing the link to the paper of George Zheng Chen. It has been most usefull to me. I think that the paper 1834 of Micael Farady is an authoritative source ("the original"). --Stenallan (talk) 17:23, 4 March 2022 (UTC)

Flow of electrons

I've posted a message to the talk page of the "Cathode" article. Summary: The "Flow of electrons" section is incorrect.

Please see the message here: Talk:Cathode#Flow_of_electrons

Czukrae (talk) 06:37, 1 October 2014 (UTC)

US battery manufacturer convention?

"In the United States, many battery manufacturers regard the positive electrode as the anode, particularly in their technical literature. Though technically incorrect,"

Is this really true? I've always seen (US) battery manufacturers refer to their negative terminals (e.g., zinc) as anodes. Can someone provide a counterexample? Karn (talk) 04:42, 23 February 2020 (UTC)

Karn is correct, so in the absence of a counterexample, I have changed the text to state that battery manufacturers refer to the negative electrode as the anode, with a citation as supporting evidence. Bruckner130564 (talk) 14:17, 24 October 2020 (UTC)

Etymology note

From the article: "Since the later discovery of the electron, an easier to remember and more durably correct technically although historically false, etymology has been suggested: anode, from the Greek anodos, 'way up', 'the way (up) out of the cell (or other device) for electrons'."

This definition was actually suggested in correspondence to Faraday at the time. See "Faraday Consults the Scholars: The Origins of the Terms of Electrochemistry," an article on JSTOR. https://www.jstor.org/stable/530887 Samer (talk) 17:30, 2 July 2022 (UTC)

There are way too many citation needed tags added February 2024. Most, if not all, are defined in all the popular references. There is no shortage. There is the small complication of reversible systems, such as rechargeable batteries. Gah4 (talk) 09:03, 7 October 2024 (UTC)