Do we know what anode is?

The author is most afraid that the inexperienced reader will not read the heading further. He believes the definition terms anode and cathode Every competent person knows that, solving a crossword puzzle, when asked about the name of the positive electrode, he immediately writes the word anode and everything fits in the cells. But there are not many things that are worse than half-knowledge.

Recently, in the Google search engine, in the “Questions and Answers” ​​section, I even found a rule by which its authors suggest remembering the definition of electrodes. Here it is:

«Cathode - negative electrode anode is positive. And remembering this is easiest if you count the letters in words. IN cathode as many letters as in the word “minus”, and in anode respectively, as much as in the term “plus”.

The rule is simple, memorable, one would have to offer it to schoolchildren if it were correct. Although the desire of teachers to put knowledge into the heads of students using mnemonics (the science of memorization) is very commendable. But back to our electrodes.

To begin with, we take a very serious document, which is the LAW for science, technology, and, of course, school. It "GOST 15596-82. SOURCES OF THE CURRENT CHEMICAL. Terms and Definitions". There, on page 3, you can read the following: “The negative electrode of a chemical current source is an electrode that, when discharged, is anode". The same thing, “A positive electrode of a chemical current source is an electrode that, when discharged, is cathode". (Terms are highlighted by me. BH). But the texts of the rule and GOST contradict each other. What is the matter?

And the thing is that, for example, a part immersed in an electrolyte for nickel plating or for electrochemical polishing may be anode and cathode depending on whether another layer of metal is applied to it or, conversely, is removed.

An electric battery is a classic example of a renewable chemical source of electric current. It can be in two modes - charging and discharging. The direction of electric current in these different cases will be directly in the battery itself oppositealthough the polarity of the electrodes does not change.

Depending on this, the purpose of the electrodes will be different. When charging, the positive electrode will receive electric current, and the negative one will release. When discharging - vice versa. In the absence of electric current, talk about anode and the cathode is meaningless.

“Therefore, in order to avoid ambiguity and uncertainty, as well as for the sake of greater accuracy, – recorded in his research M. Faraday in January 1834, – I intend to use terms in the future, the definition of which I will give now. ”

What are the reasons for introducing new terms into science by Faraday?

And here they are: “Surfaces in which, according to conventional terminology, an electric current enters and leaves a substance, are very important places of action and their must be distinguished from the poles". (Faraday. Emphasized by us. BH)

In those days, after the discovery of the phenomenon of thermoelectricity by T. Seebeck, the hypothesis that the magnetism of the Earth is due to the temperature difference between the poles and the equator was circulating, as a result of which currents arise along the equator. She was not confirmed, but served Faraday as "natural pointer»When creating new terms. Earth's magnetism has such a polarity, as if an electric current was going along the equator in the direction of the apparent movement of the sun.

Faraday writes: "Based on this view, we propose to name the surface that is directed east - the anode, and that which is directed west - the cathode."At the heart of the new terms lay the ancient Greek language and in translation they meant: anode - way (of the sun) up cathode - the path (of the sun) down.

In the Russian language there are wonderful terms SUNRISE and SUNSET, which are easy to apply for this case, but for some reason the Faraday translators did not. We recommend using them, because in them the root of the word is STROKE and, in any case, this will remind the user of the term that without the movement of current the term is not applicable. For those who want to check the reasoning of the creator of the term with the help of other rules, for example, the rules of the corker, we inform that the Earth’s north magnetic pole lies in Antarctica, near the South geographical pole.

Errors in the application of the terms ANOD and CATHOD are not numbered. Including in foreign directories and encyclopedias. Therefore, in electrochemistry they use other definitions that are more understandable to the reader. They have anode Is an electrode where oxidation processes take place, and cathode - This is the electrode where recovery processes take place. In this terminology, there is no place for electronic devices, but with electrical terminology it is easy to indicate the anode of a radio tube It includes electric current. (Not to be confused with the direction of electrons).