We all know well that electricity is a directed flow of charged particles as a result of an electric field. Any student will tell you that. But the question of what is the direction of the current and where do these very particles go can lead many to a standstill.
Essence of the question
As you know, electrons carry electricity in a conductor, cations and anions (or simply ions) in electrolytes, electrons work in so-called “holes” in semiconductors, and ions with electrons in gases. The presence of free elementary particles in a particular material determines its electrical conductivity. In the absence of an electric field in a metal conductor, current will not flow. But as soon as a potential difference arises in its two sections , i.e. voltage will appear, chaos will stop in the movement of electrons and order will come: they will begin to repulse from the minus and go towards the plus. It would seem that this is the answer to the question "What is the direction of the current?" But it was not there. It is enough to look into the encyclopedic dictionary or simply into any physics textbook, as soon as a certain contradiction becomes noticeable. It says that conditionally the phrase “current direction” means the directional movement of positive charges, in other words: from plus to minus. What to do with this statement? Indeed, there is a contradiction with the naked eye!
Strength of habit
When people learned how to make a direct current circuit, they did not yet know about the existence of an electron. Moreover, at that time they did not suspect that he was moving from minus to plus. When Ampere proposed in the first half of the 19th century the direction of the current from plus to minus, everyone took it for granted and no one disputed this decision. 70 years passed before people found out that the current in metals occurs due to the movements of electrons. And when they understood this (it happened in 1916), everyone was so used to the choice made by Amp that they no longer began to change anything.
"Golden mean"
In electrolytes, negatively charged particles move toward the cathode, and positive ones move toward the anode. The same thing happens in gases. If you think about what direction the current will be in this case, only one option comes to mind: the movement of bipolar electric charges in a closed circuit occurs towards each other. If we take this statement as a basis, then it will remove the current contradiction. This may be surprising, but even more than 70 years ago, scientists received documentary evidence that the opposite in sign electrical charges in the conductive medium actually move towards each other. This statement will be true for any conductor, regardless of its type: metal, gas, electrolyte, semiconductor. Be that as it may, it remains to be hoped that over time, physicists will eliminate the confusion in terminology and adopt an unambiguous definition of what exactly is the direction of current flow. The habit, of course, is difficult to change, but you really need to finally put everything in its place.