Electrodynamics. Study of the relationships between electrical, magnetic and mechanical phenomena. It includes the analysis of magnetic fields produced by currents, the electromotive forces induced by variable magnetic fields, the force on currents in magnetic fields, the propagation of electromagnetic waves, and the behavior of charged particles in magnetic and electric fields.

Classical electrodynamics deals with fields and charged particles in the original way systematically described by James Clerk Maxwell , while quantum electrodynamics applies the principles of quantum mechanics to electrical and magnetic phenomena. Relativistic electrodynamics deals with the behavior of charged particles and fields, when their velocity approaches the speed of light.


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  • 1 Historical Review
  • 2 Electrodynamics
  • 3 Atom
  • 4 Sources

Historical review

In 1831 , after a long series of experiments, Michael Faraday found a new relationship between electrical and magnetic effects. It was known, after the works of Oersted and Ampère, among others, that an electric current (an electric field) creates magnetic effects. Faraday was convinced of symmetry in the laws of nature, and of the observation of electrostatic induction and the “induction” of magnetic effects by electric currents believed that a magnetic field should create electrical effects. However, the relationship was more subtle: it is the variations in time of the magnetic field that create an electric field. We quote Faraday’s own words, in his presentation to the Royal Institution, London. In the introduction to the first series of experiments related to electromagnetic induction, Faraday presents the objectives and background of these investigations:


The electrodynamic is based precisely on the movement of electrons or electrical charges used as a conductive support material for electric current to move.

All bodies known in nature , whether solid, liquid or gaseous, are made up of atoms or molecules of simple or compound chemical elements. Water molecules we take to relieve thirst, for example, are formed by two atoms of hydrogen and one of oxygen (H2O).

Billions of molecules made of these two chemical elements are present in a glass of water .

All simple atoms or molecules are made up of a nucleus made up of protons and neutrons, and a cloud of electrons located in one or more orbits, depending on the chemical element in question, constantly rotates around that nucleus, similar to how planets revolve around the sun . In other words, each atom has been a miniature solar system, as can be seen in the illustration of the copper (Cu) atom, which appears on the left.

The protons of the atoms always have a positive electric charge, the neutrons have a neutral charge and the electrons have a negative electric charge.

The number of protons present in the nucleus of a neutral atom is always equal to that of the electrons that are rotating in their respective orbits. An atom in a neutral state has the same number of negative charges as positive charges.

Electro – movement


An atom can gain or yield electrons from its last orbit using chemical or electrical means and thus become a negative or positive ion of the element in question, except the atoms of the noble gases.

In that case we can say that it is the ion of a certain element such as, for example, hydrogen (H), copper (Cu), zinc (Zn), lead (Pb), etc.


When the atom gives up or loses electrons, it becomes a positive ion or cation, since the number of positively charged protons will exceed that of negatively charged electrons. If, on the other hand, instead of giving up electrons, the atom captures or gains them in its last orbit, it becomes a negative ion or anion, as the number of negatively charged electrons is greater than the positive charge of the grouped protons. in the core. It is necessary to clarify that the maximum number of electrons that the last layer or orbit of an atom can contain is eight.


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