Electricity (The transfer of energy)

Electricity.., the most common word that we hear in our day-to-day life. Though it is not visible to us, we feel incomplete in the absence of it. Our lives would be impossible to imagine without electricity. That is the impact it has on our lifestyle. Even our environment is related to electricity in the form of lightning and thundering. Regardless of its physical existence, there exists a principle in science behind it.

Electricity is a physical phenomenon that is associated with the matter and motion of charges present in it. Electricity and magnetism are relative phenomena of electromagnetism. Electricity is dependent on the presence of an electric charge (positive or negative) in matter, which produces an electric field. So, as electricity is defined as the motion of an electric charge in a particular direction, it causes an electric current and it produces a magnetic field. Notably, only negative charges (referred to as electrons) are responsible for the generation of electric current.

Electricity is of two kinds, viz., static electricity and dynamic electricity. We learned in atomic structure that an atom is neutral, with an equal number of protons and neutrons in its nucleus and electrons revolving around the nucleus in their fixed orbits. Under normal conditions, protons (referred to as positive charges) balance out electrons (referred to as negative charges) as they are equal in number. However, as per electron flow, some atoms are capable of attracting electrons while some are capable of losing electrons. Electrons in the outer orbits (known as valence electrons) of atoms are freely available (i.e., less strongly attracted to protons in the nucleus) and are, as such, called free electrons. When an external force (which is greater than the force of attraction between the electron in the valence band and the proton in the nucleus), these electrons are ready to be free from the atoms, and a steady stream of force on the electron tends to transfer its energy to the valence electron present in its neighbouring atom, and the process continues. Each of these electrons forms an electric current. Based on their ability to lose or gain electrons, the electrical conducting materials have been classified into conductors, semiconductors, and insulators. 

We are familiar with the word "static," which means "stationary or fixed." In brief, insulators are those which are not capable of losing electrons (i.e., the force of attraction between valence electron and nucleus is very high). As a result, electrons in the insulators will not transfer energy to their adjacent atoms, and no electric current is produced. Under certain conditions, the charge from a substance may be transferred to the other substance, which includes contact-induced separation, heat-and-pressure-induced separation, and charge-induced separation. We are familiar with the word "static," which means "stationary or fixed." In brief, insulators are those which are not capable of losing electrons (i.e., the force of attraction between valence electron and nucleus is very high). As a result, electrons in the insulators will not transfer energy to their adjacent atoms, and no electric current is produced. Under certain conditions, the charge from a substance may be transferred to the other substance, which includes contact-induced separation, heat-and-pressure-induced separation, and charge-induced separation.

• Contact-induced separation includes when two insulators rub against each other; since their surfaces are in contact, a chemical bond forms in between them known as adhesion, due to which a frictional force appears.
• Heat induced separation includes when an insulator material is heated up, the separation of charges occurs in the atoms.
• Pressure-induced separation occurs in a few materials, including crystals and ceramics, and occurs when molecules are subjected to pressure.
• Charge-induced separation: when a charged material is brought near a neutral one, the unlike charges inside the neutral object attract while like charges repel.

When the insulators are subjected to the above factors, the imbalance of the charges occurs in the insulators and, thereby, electrical current is produced. For example, if you take the plastic ruler and take it near to the churned paper, nothing happens. And when the same plastic ruler is rubbed continuously on a surface, the churned paper now sticks to the ruler. Here, the attraction of charges can be felt. The substance that loses electrons becomes positively charged and the substance that gains electrons becomes negatively charged. These charges are stationary and remain on the surface of the substance. Since there is no flow of electrons, this is referred to as static electricity. And this is known as static electricity.

On the other hand, metals, which are capable of losing electrons (i.e., the force of attraction between valence electron and nucleus is very high), allow their electrons to freely transfer their energy to their neighbouring atom electrons, such that an electric current is produced, which is dynamic. If the transfer of energy is in a single direction, then it is called direct current (DC), and if the direction of transfer of energy alters instantaneously, then it is called alternating current (AC). This type of electricity is known as "dynamic electricity," which is supplied to our utility.