We explain what an electrical charge is, how it is classified and what its properties are. Also, what is Coulomb's Law.
What is an electrical charge?
Inphysical, an electric charge is called aproperty of matter that is present in the subatomic particles and is evidenced by forces of attraction or repulsion between them, through fieldselectromagnetic.
Matter composed of atoms It is electrically neutral, that is, it is not charged unless some external factor charges it. Atoms have the same number of negatively charged particles (electrons) as positively charged particles (protons).
However, the matter it can be electrically charged, that is, it can gain or lose charge, and thus remain charged in a negative or positive way. The charged matter generates a electric field, a field of electrical forces. The electromagnetic force is one of the four fundamental interactions of the nature.
Electric charges cannot be created or destroyed. The amount of electrical charge in the universe it is constant, it does not change over time.
Materials respond differently to electromagnetic induction. Some are conductors of theelectricity and others are insulating, that is, they do not conduct it.
According toInternational System of Measurements (SI), electric charges are measured in a unit called Coulombs or Coulombs (C). Its name was established in honor of the French physicist Charles-Augustin de Coulomb (1736-1806), one of the greatest scholars of this type of physical phenomena.
A Coulomb unit is defined as the amount of cargo carried by a electric current of an amp for aelectrical conductor in a second. One ampere corresponds to 6.242 x 1018 free electrons.
Types of electrical charge
Electric charges interact with each other according to their type: they can be positive or negative, as Benjamin Franklin called them. These denominations are arbitrary, that is, there is nothing that distinguishes the positive from the negative, but they are thought of as a magnetic dipole, as a battery, which has a positive pole (or north) and a negative pole (or south).
The positive is denoted by the + sign and the negative by the - sign, conventionally. Electric charges with equal signs repel each other. Electric charges of opposite signs attract each other.
Properties of electric charge
Electric charge is an intrinsic property of matter, and it resides in subatomic particles: electrons are negatively charged and protons positive charge (the neutrons neutral charge, as the name suggests).
When an object becomes electrically charged, it is due to a displacement in its electrons, either loss (gaining positive charge) or incorporation (gaining negative charge). Therefore, a material with an excess of electrons in its outer atoms will present a negative charge, while one with a deficit of them will present a positive charge.
In a closed system, the electric charge remains constant, just as it occurs in any chemical reaction.
Coulomb law
The magnitude of the attractive or repulsive force depends on the charge and the distance.The Coulomb law or Fundamental Principle of Electrostatics governs the magnitude of the attractive or repulsive forces between two determined electric charges, regardless of the sign of their charge (obviously, if they are of the same sign, it will be a repulsive force, and if they are of the opposite sign, it will be an attractive force) .
According to this law, this force is proportional to the product of the value of the charges, and inversely proportional to the square of the distance that separates them. This is expressed mathematically as follows:
F = K. [(Q1 x Q2) / r2]
Where:
- F is the electric force.
- Q are the charges.
- r is the distance that separates them.
- K is a constant of proportionality defined as 9.109 N.m2 / C2.