Positive and negative charges. What is a charge? Types of charges and their interaction
« Physics - 10th grade"
First, let's consider the simplest case, when electrically charged bodies are at rest.
The branch of electrodynamics devoted to the study of the equilibrium conditions of electrically charged bodies is called electrostatics.
What is an electric charge?
What charges are there?
With words electricity, electric charge, electric current you have met many times and managed to get used to them. But try to answer the question: “What is an electric charge?” The concept itself charge- this is a basic, primary concept that cannot be reduced at the current level of development of our knowledge to any simpler, elementary concepts.
Let us first try to find out what is meant by the statement: “This body or particle has an electric charge.”
All bodies are made of tiny particles, which are indivisible into simpler ones and are therefore called elementary.
Elementary particles have mass and due to this they are attracted to each other according to the law universal gravity. As the distance between particles increases, the gravitational force decreases in inverse proportion to the square of this distance. Most elementary particles, although not all, also have the ability to interact with each other with a force that also decreases in inverse proportion to the square of the distance, but this force is many times greater than the force of gravity.
So in the hydrogen atom, shown schematically in Figure 14.1, the electron is attracted to the nucleus (proton) with a force 10 39 times greater than the force of gravitational attraction.
If particles interact with each other with forces that decrease with increasing distance in the same way as the forces of universal gravity, but exceed the gravitational forces many times, then these particles are said to have an electric charge. The particles themselves are called charged.
There are particles without an electric charge, but there is no electric charge without a particle.
The interaction of charged particles is called electromagnetic.
Electric charge determines the intensity of electromagnetic interactions, just as mass determines the intensity of gravitational interactions.
The electric charge of an elementary particle is not special mechanism in a particle, which could be removed from it, decomposed into its component parts and reassembled. The presence of an electric charge on an electron and other particles only means the existence of certain force interactions between them.
We, in essence, know nothing about charge if we do not know the laws of these interactions. Knowledge of the laws of interactions should be included in our ideas about charge. These laws are not simple, and it is impossible to outline them in a few words. Therefore, it is impossible to give a sufficiently satisfactory short definition concept electric charge.
Two signs of electric charges.
All bodies have mass and therefore attract each other. Charged bodies can both attract and repel each other. This the most important fact, familiar to you, means that in nature there are particles with electric charges of opposite signs; in the case of charges of the same sign, the particles repel, and in the case of different signs, they attract.
Charge of elementary particles - protons, which are part of all atomic nuclei, are called positive, and the charge electrons- negative. There are no internal differences between positive and negative charges. If the signs of the particle charges were reversed, then the nature of electromagnetic interactions would not change at all.
Elementary charge.
In addition to electrons and protons, there are several other types of charged elementary particles. But only electrons and protons can exist in a free state indefinitely. The rest of the charged particles live less than a millionth of a second. They are born during collisions of fast elementary particles and, having existed for an insignificantly short time, decay, turning into other particles. You will become familiar with these particles in 11th grade.
Particles that do not have an electrical charge include neutron. Its mass is only slightly greater than the mass of a proton. Neutrons, together with protons, are part of the atomic nucleus. If an elementary particle has a charge, then its value is strictly defined.
Charged bodies Electromagnetic forces in nature play a huge role due to the fact that all bodies contain electrically charged particles. The constituent parts of atoms - nuclei and electrons - have an electrical charge.
The direct action of electromagnetic forces between bodies is not detected, since the bodies in their normal state are electrically neutral.
An atom of any substance is neutral because the number of electrons in it is equal to the number of protons in the nucleus. Positively and negatively charged particles are connected to each other by electrical forces and form neutral systems.
A macroscopic body is electrically charged if it contains an excess amount of elementary particles with any one sign of charge. Thus, the negative charge of a body is due to the excess number of electrons compared to the number of protons, and the positive charge is due to the lack of electrons.
In order to obtain an electrically charged macroscopic body, that is, to electrify it, it is necessary to separate part of the negative charge from the positive charge associated with it or transfer a negative charge to a neutral body.
This can be done using friction. If you run a comb through dry hair, then a small part of the most mobile charged particles - electrons - will move from the hair to the comb and charge it negatively, and the hair will charge positively.
Equality of charges during electrification
With the help of experiment, it can be proven that when electrified by friction, both bodies acquire charges that are opposite in sign, but identical in magnitude.
Let's take an electrometer, on the rod of which there is a metal sphere with a hole, and two plates on long handles: one is made of ebonite and the other is made of plexiglass. When rubbing against each other, the plates become electrified.
Let's bring one of the plates inside the sphere without touching its walls. If the plate is positively charged, then some of the electrons from the needle and rod of the electrometer will be attracted to the plate and collected on inner surface spheres. At the same time, the arrow will be charged positively and will be pushed away from the electrometer rod (Fig. 14.2, a).
If you bring another plate inside the sphere, having first removed the first one, then the electrons of the sphere and the rod will be repelled from the plate and will accumulate in excess on the arrow. This will cause the arrow to deviate from the rod, and at the same angle as in the first experiment.
Having lowered both plates inside the sphere, we will not detect any deviation of the arrow at all (Fig. 14.2, b). This proves that the charges of the plates are equal in magnitude and opposite in sign.
Electrification of bodies and its manifestations. Significant electrification occurs during friction of synthetic fabrics. When you take off a shirt made of synthetic material in dry air, you can hear a characteristic crackling sound. Small sparks jump between the charged areas of the rubbing surfaces.
In printing houses, paper is electrified during printing and the sheets stick together. To prevent this from happening, special devices are used to drain the charge. However, the electrification of bodies in close contact is sometimes used, for example, in various electrocopying installations, etc.
Law of conservation of electric charge.
Experience with the electrification of plates proves that during electrification by friction, a redistribution of existing charges occurs between bodies that were previously neutral. A small portion of electrons moves from one body to another. In this case, new particles do not appear, and pre-existing ones do not disappear.
When bodies are electrified, law of conservation of electric charge. This law is valid for a system into which charged particles do not enter from the outside and from which they do not leave, i.e. for isolated system.
In an isolated system algebraic sum the charges of all bodies are conserved.
q 1 + q 2 + q 3 + ... + q n = const. (14.1)
where q 1, q 2, etc. are the charges of individual charged bodies.
The law of conservation of charge has a deep meaning. If the number of charged elementary particles does not change, then the fulfillment of the charge conservation law is obvious. But elementary particles can transform into each other, be born and disappear, giving life to new particles.
However, in all cases, charged particles are born only in pairs with charges of the same magnitude and opposite in sign; Charged particles also disappear only in pairs, turning into neutral ones. And in all these cases, the algebraic sum of the charges remains the same.
The validity of the law of conservation of charge is confirmed by observations of a huge number of transformations of elementary particles. This law expresses one of the most fundamental properties of electric charge. The reason for the charge retention is still unknown.
We have to literally peel freshly washed clothes from the dryer one from another, or when we just can’t get our electrified and literally standing on end hair in order. Who hasn't tried to hang balloon to the ceiling after rubbing it against your head? This attraction and repulsion is a manifestation static electricity. Such actions are called electrification.
Static electricity is explained by its existence in nature electric charge. Charge is an integral property of elementary particles. The charge that appears on glass when it is rubbed against silk is conventionally called positive, and the charge arising on ebonite during friction with wool is negative.
Let's consider an atom. An atom consists of a nucleus and electrons flying around it (blue particles in the figure). The nucleus is made up of protons (red) and neutrons (black).
.The carrier of a negative charge is an electron, a positive charge is a proton. A neutron is a neutral particle and has no charge.
Magnitude elementary charge- electron or proton, has a constant value and is equal to
The entire atom is neutrally charged if the number of protons matches the number of electrons. What happens if one electron breaks off and flies away? The atom will have one more proton, that is, there will be more positive particles than negative ones. Such an atom is called positive ion. And if one extra electron joins, we get negative ion. The electrons, having come off, may not rejoin, but move freely for some time, creating a negative charge. Thus, free charge carriers in a substance are electrons, positive ions and negative ions.
In order for there to be a free proton, the nucleus must be destroyed, and this means the destruction of the entire atom. We will not consider such methods of obtaining electric charges.
A body becomes charged when it contains an excess of one or other charged particles (electrons, positive or negative ions).
The amount of charge on a body is a multiple of the elementary charge. For example, if a body has 25 free electrons and the remaining atoms are neutral, then the body is negatively charged and its charge is . The elementary charge is not divisible - this property is called discreteness
Like charges (two positive or two negative) repulse, opposite (positive and negative) - are attracted
Point charge- is a material point that has an electric charge.
Law of conservation of electric charge
A closed system of bodies in electricity is a system of bodies when there is no exchange of electric charges between external bodies.
The algebraic sum of the electric charges of bodies or particles remains constant during any processes occurring in an electrically closed system.
The figure shows an example of the law of conservation of electric charge. In the first picture there are two bodies of opposite charges. The second picture shows the same bodies after contact. In the third figure, a third neutral body was introduced into an electrically closed system and the bodies were brought into interaction with each other.
In each situation, the algebraic sum of the charge (taking into account the sign of the charge) remains constant.
The main thing to remember
1) Elementary electric charge - electron and proton
2) The amount of elementary charge is constant
3) Positive and negative charges and their interaction
4) Free charge carriers are electrons, positive ions and negative ions
5) Electric charge is discrete
6) Law of conservation of electric charge
Electric charge– a physical quantity characterizing the ability of bodies to enter into electromagnetic interactions. Measured in Coulombs.
Elementary electric charge– the minimum charge that elementary particles have (proton and electron charge).
The body has a charge, means it has extra or missing electrons. This charge is designated q=ne. (it is equal to the number of elementary charges).
Electrify the body– create an excess and deficiency of electrons. Methods: electrification by friction And electrification by contact.
Point dawn d is the charge of the body, which can be taken as a material point.
Test charge(
) – point, small charge, always positive – used to study the electric field.
Law of conservation of charge:in an isolated system, the algebraic sum of the charges of all bodies remains constant for any interactions of these bodies with each other.
Coulomb's law:the forces of interaction between two point charges are proportional to the product of these charges, inversely proportional to the square of the distance between them, depend on the properties of the medium and are directed along the straight line connecting their centers.
, Where 
F/m, Cl 2 /nm 2 – dielectric. fast. vacuum
- relates. dielectric constant (>1)
- absolute dielectric permeability. environment
Electric field– a material medium through which the interaction of electric charges occurs.
Electric field properties:
Electric field characteristics:
Tension(E) is a vector quantity equal to the force acting on a unit test charge placed at a given point.
Measured in N/C. 
Direction– the same as that of the acting force.
Tension does not depend neither on the strength nor on the size of the test charge.
Superposition of electric fields: the field strength created by several charges is equal to the vector sum of the field strengths of each charge:
Graphically The electronic field is represented using tension lines.
Tension line– a line whose tangent at each point coincides with the direction of the tension vector.
Properties of tension lines: they do not intersect, only one line can be drawn through each point; they are not closed, they leave a positive charge and enter a negative one, or dissipate into infinity.
Types of fields:
Homogeneous electric field – a field whose intensity vector at each point is the same in magnitude and direction.
Non-uniform electric field– a field whose intensity vector at each point is unequal in magnitude and direction.
Constant electric field– the tension vector does not change.
Variable electric field– the tension vector changes.
Work done by an electric field to move a charge.
, where F is force, S is displacement, 
- angle between F and S.
For a uniform field: the force is constant.
The work does not depend on the shape of the trajectory; the work done to move along a closed path is zero.
For a non-uniform field:
Electric field potential– the ratio of the work that the field does, moving a test electric charge to infinity, to the magnitude of this charge.
-potential– energy characteristic of the field. Measured in Volts
Potential difference:
If 
, That 
, Means 
-potential gradient.
For a uniform field: potential difference – voltage:
. It is measured in Volts, the devices are voltmeters.
Electrical capacity– the ability of bodies to accumulate electrical charge; the ratio of charge to potential, which is always constant for a given conductor.
.
Does not depend on charge and does not depend on potential. But it depends on the size and shape of the conductor; on the dielectric properties of the medium.
, where r is the size, 
- permeability of the environment around the body.
Electrical capacity increases if any bodies - conductors or dielectrics - are nearby.
Capacitor– device for accumulating charge. Electrical capacity: 
Flat capacitor– two metal plates with a dielectric between them. Electric capacity of a flat capacitor:
, where S is the area of the plates, d is the distance between the plates.
Energy of a charged capacitor equal to the work done by the electric field when transferring charge from one plate to another.
Small charge transfer 
, the voltage will change to 
, the work is done 
. Because 
, and C =const, 
. Then 
. Let's integrate:
Electric field energy:
, where V=Sl is the volume occupied by the electric field
For a non-uniform field:
.
Volumetric electric field density:
. Measured in J/m 3.
Electric dipole– a system consisting of two equal, but opposite in sign, point electric charges located at some distance from each other (dipole arm -l).
The main characteristic of a dipole is dipole moment– a vector equal to the product of the charge and the dipole arm, directed from the negative charge to the positive one. Designated 
. Measured in Coulomb meters.
Dipole in a uniform electric field.
The following forces act on each charge of the dipole: 
And 
. These forces are oppositely directed and create a moment of a pair of forces - a torque:, where
M – torque F – forces acting on the dipole
d – sill arm – dipole arm
p – dipole moment E – tension
- angle between p Eq – charge
Under the influence of a torque, the dipole will rotate and align itself in the direction of the tension lines. Vectors p and E will be parallel and unidirectional.
Dipole in a non-uniform electric field.
There is a torque, which means the dipole will rotate. But the forces will be unequal, and the dipole will move to where the force is greater.
-tension gradient. The higher the tension gradient, the higher the lateral force that pulls the dipole. The dipole is oriented along the lines of force.
Dipole intrinsic field.
But . Then:
.
Let the dipole be at point O and its arm small. Then:
.
The formula was obtained taking into account: 
Thus, the potential difference depends on the sine of the half angle at which the dipole points are visible, and the projection of the dipole moment onto the straight line connecting these points.
Dielectrics in an electric field.
Dielectric- a substance that does not have free charges, and therefore does not conduct electric current. However, in fact, conductivity exists, but it is negligible.
Dielectric classes:
with polar molecules (water, nitrobenzene): the molecules are not symmetrical, the centers of mass of positive and negative charges do not coincide, which means they have a dipole moment even in the case when there is no electric field.
with non-polar molecules (hydrogen, oxygen): the molecules are symmetrical, the centers of mass of positive and negative charges coincide, which means they do not have a dipole moment in the absence of an electric field.
crystalline (sodium chloride): a combination of two sublattices, one of which is positively charged and the other negatively charged; in the absence of an electric field, the total dipole moment is zero.
Polarization– the process of spatial separation of charges, the appearance of bound charges on the surface of the dielectric, which leads to a weakening of the field inside the dielectric.
Polarization methods:
Method 1 – electrochemical polarization:
On the electrodes – movement of cations and anions towards them, neutralization of substances; areas of positive and negative charges are formed. The current gradually decreases. The rate of establishment of the neutralization mechanism is characterized by the relaxation time - this is the time during which the polarization emf increases from 0 to a maximum from the moment the field is applied. 
= 10 -3 -10 -2 s.
Method 2 – orientational polarization:
Uncompensated polar ones are formed on the surface of the dielectric, i.e. the phenomenon of polarization occurs. The voltage inside the dielectric is less than the external voltage. Relaxation time: 
= 10 -13 -10 -7 s. Frequency 10 MHz.
Method 3 – electronic polarization:
Characteristic of non-polar molecules that become dipoles. Relaxation time: 
= 10 -16 -10 -14 s. Frequency 10 8 MHz.
Method 4 – ion polarization:
Two lattices (Na and Cl) are displaced relative to each other.
Relaxation time: 
Method 5 – microstructural polarization:
Characteristic of biological structures when charged and uncharged layers alternate. There is a redistribution of ions on semi-permeable or ion-impermeable partitions.
Relaxation time: 
=10 -8 -10 -3 s. Frequency 1KHz
Numerical characteristics of the degree of polarization:
Electricity– this is the ordered movement of free charges in matter or in a vacuum.
Conditions for the existence of electric current:
presence of free charges
the presence of an electric field, i.e. forces acting on these charges
Current strength– a value equal to the charge that passes through any cross section of a conductor per unit of time (1 second)
Measured in Amperes.
n – charge concentration
q – charge value
S – cross-sectional area of the conductor
- speed of directional movement of particles.
The speed of movement of charged particles in an electric field is small - 7 * 10 -5 m/s, the speed of propagation of the electric field is 3 * 10 8 m/s.
Current Density– the amount of charge passing through a cross section of 1 m2 in 1 second.
. Measured in A/m2.
- the force acting on the ion from the electric field is equal to the friction force
- ion mobility
- speed of directional movement of ions = mobility, field strength
The greater the concentration of ions, their charge and mobility, the greater the specific conductivity of the electrolyte. As the temperature increases, the mobility of ions increases and the electrical conductivity increases.
I think I’m not the only one who wanted and still wants to combine a formula that describes the gravitational interaction of bodies (Law of Gravity) , with a formula dedicated to the interaction of electric charges (Coulomb's law ). So let's do it!
It is necessary to put an equal sign between concepts weight And positive charge , as well as between concepts antimass And negative charge .
Positive charge (or mass) characterizes Yin particles (with Attraction Fields) – i.e. absorbing ether from the surrounding etheric field.
And a negative charge (or antimass) characterizes Yang particles (with Repulsion Fields) - i.e. emitting ether into the surrounding etheric field.
Strictly speaking, mass (or positive charge), as well as antimass (or negative charge) indicates to us that a given particle absorbs (or emits) Ether.
As for the position of electrodynamics that there is a repulsion of charges of the same sign (both negative and positive) and an attraction of charges of different signs to each other, it is not entirely accurate. And the reason for this is a not entirely correct interpretation of experiments on electromagnetism.
Particles with Attractive Fields (positively charged) will never repel each other. They just attract. But particles with Repulsion Fields (negatively charged), indeed, will always repel each other (including from the negative pole of the magnet).
Particles with Attractive Fields (positively charged) attract any particles to themselves: both negatively charged (with Repulsion Fields) and positively charged (with Attractive Fields). However, if both particles have an Attractive Field, then the one whose Attractive Field is larger will displace the other particle towards itself to a greater extent than will the particle with a smaller Attractive Field.
Matter – antimatter.
In physics matter are called bodies, and also chemical elements, from which these bodies are built, and also elementary particles. In general, it can be considered approximately correct to use the term in this way. After all Matter , from an esoteric point of view, these are power centers, spheres of elementary particles. Chemical elements are built from elementary particles, and bodies are built from chemical elements. But in the end it turns out that everything consists of elementary particles. But to be precise, around us we see not Matter, but Souls - i.e. elementary particles. Elementary particle in contrast to the power center (i.e., the Soul, as opposed to Matter), is endowed with a quality - Ether is created and disappears in it.
Concept substance can be considered synonymous with the concept of matter used in physics. Substance is, in the literal sense, what things around a person are made of, i.e. chemical elements and their compounds. And chemical elements, as already indicated, consist of elementary particles.
For substance and matter in science there are antonymous concepts - antimatter And antimatter , which are synonymous with each other.
Scientists recognize the existence of antimatter. However, what they think is antimatter is not actually antimatter. In fact, antimatter has always been at hand in science and has been indirectly discovered a long time ago, since experiments on electromagnetism began. And we can constantly feel the manifestations of its existence in the world around us. Antimatter arose in the Universe along with matter at the very moment when elementary particles (Souls) appeared. Substance – these are Yin particles (i.e. particles with Attraction Fields). Antimatter (antimatter) are Yang particles (particles with Repulsion Fields).
The properties of Yin and Yang particles are directly opposite, and therefore they are perfect for the role of the sought-after matter and antimatter.
The ether that fills elementary particles is their driving factor
“The power center of an elementary particle always strives to move together with the Ether, which in this moment fills this particle (and forms it), in the same direction and at the same speed."
Ether is the driving factor of elementary particles. If the Ether, which fills the particle, is at rest, then the particle itself will be at rest. And if the Ether of a particle moves, the particle will also move.
Thus, due to the fact that there is no difference between the Ether of the etheric field of the Universe and the Ether of particles, all the Principles of Ether behavior are applicable to elementary particles. If the Ether, which belongs to the particle, is currently moving towards the occurrence of a lack of Ether (in accordance with the first principle of the behavior of the Ether - “There are no etheric voids in the etheric field”) or moving away from the excess (in accordance with the second principle of the behavior of the Ether - “In In the ethereal field, there are no areas with excess ether density"), the particle will move with it in the same direction and at the same speed.
What is Strength? Classification of Forces
One of the fundamental quantities in physics in general, and especially in one of its subsections - in mechanics, is Force . But what is it, how can it be characterized and supported by something that exists in reality?
First, let's open any Physical Encyclopedic Dictionary and read the definition.
« Force in mechanics - a measure of the mechanical action of other bodies on a given material body" (FES, "Force", edited by A. M. Prokhorov).
As you can see, the Force in modern physics does not carry information about something specific, material. But at the same time, the manifestations of the Force are more than specific. In order to correct the situation, we need to look at the Force from the perspective of the occult.
From an esoteric point of view Force – this is nothing more than Spirit, Ether, Energy. And the Soul, as you remember, is also a Spirit, only “wound in a ring.” Thus, both the free Spirit is Power, and the Soul (locked Spirit) is Power. This information will greatly help us in the future.
Despite some vagueness in the definition of Force, it has a completely material basis. This is not at all an abstract concept, as it appears in physics at present.
Force- this is the reason that causes Ether to approach its deficiency or move away from its excess. We are interested in the Ether contained in Elementary Particles (Souls), therefore, for us, Force is, first of all, the reason that encourages particles to move. Any elementary particle is a Force, since it directly or indirectly affects other particles.
You can measure Strength using speed, with which the Ether of the particle would move under the influence of this Force, if no other Forces acted on the particle. Those. the speed of the ethereal flow causing the particle to move is the magnitude of this Force.
Let us classify all types of Forces arising in particles depending on the cause that causes them.
Force of Attraction (Striving of Attraction).
The reason for the emergence of this Power is any lack of Ether that arises anywhere in the etheric field of the Universe.
Those. the cause of the emergence of the Attractive Force in a particle is any other particle that absorbs the Ether, i.e. forming the Field of Attraction.
Repulsion Force (Repulsion Tendency).
The reason for the emergence of this Force is any excess of Ether that arises anywhere in the etheric field of the Universe.
Occurring in nature physical processes are not always explained by the laws of molecular kinetic theory, mechanics or thermodynamics. There are also electromagnetic forces that act at a distance and do not depend on the mass of the body.
Their manifestations were first described in the works of ancient Greek scientists, when they attracted light, small particles of individual substances with amber rubbed on wool.
Historical contribution of scientists to the development of electrodynamics
Experiments with amber were studied in detail by an English researcher William Gilbert. IN recent years In the 16th century, he made a report on his work, and designated objects capable of attracting other bodies at a distance with the term “electrified.”
The French physicist Charles Dufay determined the existence of charges with opposite signs: some were formed by the friction of glass objects on silk fabric, and others by resins on wool. That’s what he called them: glass and resin. After completing the research Benjamin Franklin The concept of negative and positive charges was introduced.
Charles Coulomb realized the possibility of measuring the force of charges with the design of torsion balances of his own invention.
Robert Millikan, based on a series of experiments, established the discrete nature of the electrical charges of any substance, proving that they consist of a certain number of elementary particles. (Not to be confused with another concept of this term - fragmentation, discontinuity.)
The works of these scientists served as the foundation modern knowledge about processes and phenomena occurring in electrical and magnetic fields, created by electric charges and their movement, studied by electrodynamics.
Definition of charges and principles of their interaction
Electric charge characterizes the properties of substances that provide them with the ability to create electric fields and interact in electromagnetic processes. It is also called the amount of electricity and is defined as a physical scalar quantity. To denote charge, the symbols “q” or “Q” are used, and in measurements they use the “Coulomb” unit, named after the French scientist who developed a unique technique.
He created a device whose body used balls suspended on a thin thread of quartz. They were oriented in space in a certain way, and their position was recorded relative to a graduated scale with equal divisions.
Through a special hole in the lid, another ball with an additional charge was brought to these balls. The emerging interaction forces caused the balls to deflect and turn their rocker arm. The magnitude of the difference in readings on the scale before and after the introduction of a charge made it possible to estimate the amount of electricity in the test samples.
A charge of 1 coulomb is characterized in the SI system by a current of 1 ampere passing through the cross-section of a conductor in a time equal to 1 second.
Modern electrodynamics divides all electric charges into:
positive;
negative.
When they interact with each other, they develop forces, the direction of which depends on the existing polarity.
Charges of the same type, positive or negative, always repel in opposite directions, trying to move as far away from each other as possible. And charges of opposite signs have forces that tend to bring them closer together and unite them into one whole.
Superposition principle
When there are several charges in a certain volume, the principle of superposition applies to them.
Its meaning is that each charge in a certain way, according to the method discussed above, interacts with all the others, being attracted to those of different types and repelled by those of the same type. For example, a positive charge q1 is affected by the force of attraction F31 to the negative charge q3 and repulsion force F21 from q2.
The resulting force F1 acting on q1 is determined by the geometric addition of the vectors F31 and F21. (F1= F31+ F21).
The same method is used to determine the resulting forces F2 and F3 on charges q2 and q3, respectively.
Using the principle of superposition, it was concluded that for a certain number of charges in a closed system, steady electrostatic forces act between all its bodies, and the potential at any specific point in this space is equal to the sum of the potentials from all individually applied charges.
The effect of these laws is confirmed by the created devices electroscope and electrometer, which have general principle work.
An electroscope consists of two identical blades of thin foil suspended in an isolated space by a conductive thread attached to a metal ball. In the normal state, charges do not act on this ball, so the petals hang freely in the space inside the device’s bulb.
How can charge be transferred between bodies?
If you bring a charged body, for example, a stick, to the electroscope ball, the charge will pass through the ball along a conductive thread to the petals. They will receive the same charge and begin to move away from each other by an angle proportional to the applied amount of electricity.
The electrometer has the same basic device, but it has slight differences: one petal is fixed stationary, and the second extends from it and is equipped with an arrow that allows you to take a reading from a graduated scale.
To transfer charge from a remote, stationary and charged body to an electrometer, you can use intermediate carriers.
Measurements made with an electrometer do not have high class accuracy and on their basis it is difficult to analyze the forces acting between charges. Coulomb torsional balances are more suitable for their study. They use balls with diameters significantly smaller than their distance from each other. They have the properties of point charges - charged bodies, the dimensions of which do not affect the accuracy of the device.
Measurements performed by Coulomb confirmed his guess that a point charge is transferred from a charged body to a body of the same properties and mass, but uncharged, in such a way as to be evenly distributed between them, decreasing by a factor of 2 at the source. In this way, it was possible to reduce the amount of charge by two, three, or other times.
The forces that exist between stationary electric charges are called Coulomb or static interaction. They are studied by electrostatics, which is one of the branches of electrodynamics.
Types of electric charge carriers
Modern science considers the smallest negatively charged particle to be the electron, and the positron to be the smallest positively charged particle. They have the same mass 9.1·10-31 kg. The elementary particle proton has only one positive charge and a mass of 1.7·10-27 kg. In nature, the number of positive and negative charges is balanced.
In metals, the movement of electrons creates, and in semiconductors, the carriers of its charges are electrons and holes.
In gases, current is generated by the movement of ions - charged non-elementary particles (atoms or molecules) with positive charges, called cations or negative charges - anions.
Ions are formed from neutral particles.
A positive charge is created by a particle that has lost an electron under the influence of a powerful electrical discharge, light or radioactive irradiation, wind flow, movement of water masses or a number of other reasons.
Negative ions are formed from neutral particles that have additionally received an electron.
Use of ionization for medical purposes and everyday life
Researchers have long noticed the ability of negative ions to affect the human body, improve the consumption of oxygen in the air, deliver it faster to tissues and cells, and accelerate the oxidation of serotonin. All this together significantly improves immunity, improves mood, and relieves pain.
The first ionizer used to treat people was called Chizhevsky chandeliers, in honor of the Soviet scientist who created a device that has a beneficial effect on human health.
In modern electrical appliances for work in living conditions you can find built-in ionizers in vacuum cleaners, humidifiers, hair dryers, dryers...
Special air ionizers purify the air and reduce the amount of dust and harmful impurities.
Water ionizers can reduce the amount of chemical reagents in its composition. They are used to clean pools and ponds, saturating the water with copper or silver ions, which reduce the growth of algae and destroy viruses and bacteria.
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