One of the most important definitions of physics states that an electric current - is any orderly movement of particles having a charge.From this we can conclude that to electric current appeared necessary in the presence of metals, liquids or any other material of the free electrons or ions, which will move under the influence of the electromagnetic field.At the same time, the electric current in the various media will possess certain features, due to which its flow in each will be different.
If we consider the features of the formation and flow of electric current in metals, the first thing you should pay attention to the actual structure of the metal, which is a crystal lattice.In the nodes of the lattice are arranged ions with a positive charge, and in the space between the nodes in a random order moving electrons with a negative charge.If you create an electric field around the metal, the motion of the electrons take a more orderly.It can be concluded that, with respect to metals electric current - it is directed movement of electrons.
The main characteristic of the flow of electric current in metals is a current-voltage expression, known as Ohm's law.According to this law, the current is directly dependent on the voltage and inversely proportional to the resistance.Analyzing the electric current in a variety of environments, it is necessary to pay special attention to its formation and leakage in a liquid medium.
electric current in electrolytes is caused by the reaction, known electrolytic dissociation.Its essence lies in the decay of molecules alkalis, salts or acids into positive and negative ions, which are carriers of electric charge in liquids.The thing is that when the solution starts to operate the electromagnetic field, the chaotic motion of the ions is transformed into an ordered.At the same time positive ions begin to move toward the electrode having a negative charge, and the negative - to having a positive charge.Thus, in contrast to the same metal, the electric current in the electrolyte is an orderly movement of ions.Furthermore, it is worth noting that during the passage of these ions through the solution to always electrodes are formed of substances which are structural components of the solution, whether it is an alkali, an acid or a salt thereof.This phenomenon, called electrolysis, is widely used in industry for obtaining pure metals and for coating and polishing of particular products.
considering the electric current in various media, particularly in metals in liquids, we pointed out the fact that these substances are already free ions or electrons.What happens to the gas, which is known, consists of neutral molecules?Electric current without free particles with a negative or positive charge is possible, so to start the gas must be ionized, i.e. create charged particles therein.Spent for this energy will be the ionization energy, which reaches the maximum value of inert gases, and the minimum - at the alkali-metal atoms.The ionization of the gas leads to the fact that it consists of three different types of charged particles - electrons have a negative charge, as well as the positive and negative ions.All these particles under the influence of external fields begin to move in an orderly, keeping the same principle as that of the motion of ions in liquids.Thus, the electric current in the gases is directed movement as the ions (positive and negative) and electrons.
Concluding, we note the following: an electrical current in different environments has its own characteristics, which are widely used in various fields of national economy, as well as in research experiments.
