What is the directed movement of charged particles? For many, this is an incomprehensible area, but in fact everything is very simple. So, when they talk about the directed movement of charged particles, they mean current. Let's look into its main characteristics and formulations, as well as consider security issues when working with it.
General information
Start with a definition. Electric current always means the ordered (directed) movement of charged particles, which is carried out under the influence of an electric field. What kind of objects can be considered in this case? Particles mean electrons, ions, protons, holes. It is also important to know what the current strength is. This is the number of charged particles that flow through the cross section of the conductor per unit of time.
Nature of the phenomenon
All physical substances are made up of molecules that are formed from atoms. They are also not the final material, because they have elements (a nucleus and electrons revolving around it). All chemical reactions are accompanied by the movement of particles. For example, with the participation of electrons, some atoms will experience their deficiency, while others will experience an excess. In this case, the substances have opposite charges. If their contact occurs, then the electrons from one will tend to go to the other.
Such physical nature of elementary particles explains the essence of electric current. This directional movement of charged particles will continue until the values equalize. In this case, the reaction of changes is a chain. In other words, instead of the departed electron, another one comes in its place. Particles of the neighboring atom are used for replacement. But the chain doesn't end there either. An electron can also come to the extreme atom, for example, from the negative pole of the source of the flowing current.
An example of such a situation is a battery. From the negative side of the conductor, the electrons move to the positive pole of the source. When all the particles in the negatively infected component run out, the current stops. In this case, the battery is said to be dead. What is the speed of the directed movement of charged particles moving in this way? Answering this question is not as easy as it might seem at first glance.
The role of stress
What is this concept used for? Voltage is a characteristic of an electric field, which is the potential difference between two points that are inside it. To many, this may seem confusing. When it comes to the directed (ordered) movement of charged particles, then you need to understand the voltage.
Let's imagine that we have a simple conductor. This may be a wire made of metal, such as copper or aluminum. In our case, this is not so important. The mass of an electron is 9.10938215(45)×10-31kg. This means that it is quite material. But the conductor metal is solid. How, then, can electrons flow through it?
Why can there be current in metal products
Let's turn to the basics of chemistry, which each of us had the opportunity to learn in school. If the number of electrons in the substance is equal to the number of protons, then the neutrality of the element is ensured. Based on the periodic law of Mendeleev, it is determined which substance has to be de alt with. It depends on the number of protons and neutrons. It is impossible to ignore the big difference between the masses of the nucleus and electrons. If they are removed, then the weight of the atom will remain practically unchanged.
For example, the mass of a proton is approximately 1836 greater than the value of an electron. But these microscopic particles are very important, because they can easily leave some atoms and join others. At the same time, a decrease or increase in their number leads toto change the charge of the atom. If we consider a single atom, then its number of electrons will always be variable. They are constantly leaving and coming back. This is due to thermal motion and energy loss.
Chemical specificity of a physical phenomenon
When there is a directed movement of electrically charged particles, is not the atomic mass lost? Does the composition of the conductor change? This is a very important misconception that confuses many. The answer in this case is only negative. This is due to the fact that chemical elements are determined not by their atomic mass, but by the number of protons that are in the nucleus. The presence or absence of electrons/neutrons does not play a role in this case. In practice, it looks like this:
- Add or subtract electrons. It turns out an ion.
- Add or subtract neutrons. It turns out an isotope.
The chemical element does not change. But with protons, the situation is different. If it is only one, then we have hydrogen. Two protons - and we are talking about helium. The three particles are lithium. Etc. Those who are interested in the continuation can look at the periodic table. Remember: even though a current is passed through a conductor a thousand times, its chemical composition will not change. But perhaps otherwise.
Electrolytes and other interesting points
The peculiarity of electrolytes is that it is their chemical composition that changes. Then, under the influence of current,electrolyte elements. When their potential is exhausted, the directed movement of charged particles will stop. This situation is due to the fact that charge carriers in electrolytes are ions.
In addition, there are chemical elements without electrons at all. An example would be:
- Atomic cosmic hydrogen.
- All substances that are in the state of plasma.
- Gases in the upper atmosphere (not only the Earth, but also other planets where there are air masses).
- Contents of accelerators and colliders.
It should also be noted that under the influence of an electric current, some chemicals can literally crumble. A well-known example is a fuse. What does it look like on a micro level? The moving electrons push the atoms in their path. If the current is very strong, then the crystal lattice of the conductor cannot withstand and is destroyed, and the substance is melted.
Back to speed
Earlier, this point was superficially touched upon. Now let's take a closer look at it. It should be noted that the concept of the speed of directed motion of charged particles in the form of an electric current does not exist. This is due to the fact that different values are intertwined. So, an electric field propagates through a conductor at a speed that is close to the movement of light, that is, about 300,000 kilometers per second.
Under its influence, all electrons begin to move. But their speedvery small. It is approximately 0.007 millimeters per second. At the same time, they also randomly rush about in thermal motion. In the case of protons and neutrons, the situation is different. They are too big for the same events to happen to them. As a rule, it is not necessary to talk about their speed as close to the value of light.
Physical parameters
Now let's look at what is the movement of charged particles in an electric field from a physical point of view. To do this, let's imagine that we have a cardboard box that holds 12 bottles of carbonated drink. At the same time, there is an attempt to place another container there. Let's assume it succeeded. But the box barely survived. When you try to put another bottle in, it breaks, and all the containers fall out.
The box in question can be compared to the cross section of a conductor. The higher this parameter (thicker wire), the more current it can provide. This determines what volume the directed motion of charged particles can have. In our case, a box containing from one to twelve bottles can easily fulfill its intended purpose (it will not burst). By analogy, we can say that the conductor will not burn.
If you exceed the indicated value, the object will fail. In the case of a conductor, resistance will come into play. Ohm's law describes the directed motion of electrically charged particles very well.
Relationship between different physical parameters
Per boxfrom our example, you can put one more. In this case, not 12, but as many as 24 bottles can be placed per unit area. We add one more - and there are thirty-six of them. One of the boxes can be considered as a physical unit, analogous to voltage.
The wider it is (thus reducing the resistance), the more bottles (which in our example replace the current) can be placed. By increasing the stack of boxes, you can place additional containers per unit area. In this case, the power increases. This does not destroy the box (conductor). Here is a summary of this analogy:
- Total number of bottles increases power.
- The number of containers in the box indicates the current strength.
- The number of boxes in height allows you to judge the voltage.
- The width of the box gives an idea of the resistance.
Possible hazards
We have already discussed that the directed movement of charged particles is called current. It should be noted that this phenomenon can be dangerous to human he alth and even life. Here is a summary of the properties of electric current:
- Provides heating of the conductor through which it flows. If the household electrical network is overloaded, then the insulation will gradually char and crumble. As a result, there is a possibility of a short circuit, which is very dangerous.
- Electric current, when it flows through household appliances and wires, meetsresistance of elements forming materials. Therefore, it chooses the path that has the minimum value for this parameter.
- If a short circuit occurs, the current strength increases sharply. This releases a significant amount of heat. It can melt metal.
- Short circuit may occur due to moisture ingress. In the cases discussed earlier, nearby objects light up, but in this case, people always suffer.
- Electrical shock carries a significant danger. It is quite likely even fatal. When an electric current flows through the human body, the resistance of tissues is greatly reduced. They start to heat up. In this case, cells are destroyed and nerve endings die.
Security Issues
To avoid exposure to electric current, you must use special protective equipment. Work should be carried out in rubber gloves using a mat of the same material, discharge rods, as well as grounding devices for workplaces and equipment.
Circuit switches with various protections have proven to be good as a device that can save a person's life.
Also, one should not forget about basic safety precautions when working. If a fire occurs involving electrical equipment, only carbon dioxide and powder fire extinguishers can be used. The latter show the best result in the fight against fire, but equipment covered with dust cannot always be restored.
Conclusion
Using examples understandable to every reader, we found out that the ordered directed movement of charged particles is called electric current. This is a very interesting phenomenon, important from the positions of both physics and chemistry. Electric current is a tireless assistant to man. However, it must be handled with care. The article discusses security issues that should be paid attention to if there is no desire to die.
