How to find a charge?
Electric charge is a physical quantity that determines the body’s ability to participate in electromagnetic interactions. A body with a non-zero charge forms around itself an electric field that interacts with any other body that has a charge.
What is the charge measured
In order to answer the question of how to find a charge, you need to know what it is measured in and what formulas to apply. The charge is measured in pendants (C). The unit is named after Charles Coulomb, a physicist and engineer who made a significant contribution to the development of knowledge about electricity.
Tasks on how to find the charge q (this letter denotes this physical quantity) are studied in school as part of electrostatics - part of a physics course. The main law of electrostatics is the Coulomb law, which is mathematically written as follows:
F = k (q1 * q2) / r2, (1)
where F is the force with which charged bodies act on each other, q is the charges of the bodies, r is the distance between them, k is the coefficient.
If the force, the charge of one of the bodies and the distance between them is known, then the problem of how to find the electric charge of the second body is solved from equation (1) very simply.
What particles are charged
Elementary particles - electrons and protons - have a charge. And the charge modules of these particles are the same. Only their signs are different. Each atom consists of the same number of these particles. Accordingly, the total charge of an atom is zero.
Protons (together with neutrons having a zero charge) make up the nucleus of an atom. Around the nucleus at a large (by the standards of the size of the nucleus itself), electrons rotate. The force described by formula (1) holds electrons in their orbits. However, the atoms of some substances hold electrons that are at the highest energy levels (farthest from the nucleus), rather weakly, and these electrons easily come off and “travel” between the atoms.
If a part of these electrons is taken away from one body and transferred to another, then both bodies will become electrically charged. The first will receive a positive charge (due to a shortage of electrons), the second - a negative (due to their overabundance). Atoms that have lost or gained extra electrons are called ions. Accordingly, the process of giving or receiving additional electrons is called ionization.
In the school course of chemistry and physics, there are also problems on how to find the charge of the nucleus of an atom. This is very easy to do: you need to multiply the number of protons present in the nucleus by the charge of one proton. The proton charge is one of the elementary physical constants.
To find out the number of protons in the nucleus of an atom, you should look into the periodic table: this number is the ordinal number of the desired substance.