Electricity is the most common form of energy. Electricity is used for various applications like lighting, transportation, cooking, communication, production of various goods in factories and many more. None of us know exactly what electricity is. The concept of electricity, and the ideas behind it, can be developed by looking at its various behaviors. To observe the nature of electricity it is necessary to study the structure of matter. Every substance in this universe is made up of very small particles called molecules. A molecule is the smallest particle of a substance that contains all the properties of that substance. Molecules are made up of even smaller particles called atoms. We know that An atom is the smallest particle of an element that can exist.
There are two types of matter. Substances, which are molecules made up of identical atoms, are known as elements. A substance whose molecules consist of different atoms is called a compound. The concept of electricity can be derived from the atomic structure of matter.
Structure of Atom:
An atom consists of a central nucleus. The nucleus is made up of positively charged protons and less charged neutrons. This nucleus is surrounded by a number of orbital electrons. Each electron has a negative charge of – 1.602 × 10–19 coulomb and each proton in the nucleus has a positive charge of +1.602 × 10–19 coulomb. There is some attractive force between the nucleus and the orbiting electron due to the opposite charge. The mass of the electron is relatively negligible compared to the mass of the nucleus. The mass of each proton and neutron is 1840 times the mass of an electron.
Since each electron and each proton have the same modulus value, the number of electrons is equal to the number of protons in an electrically neutral atom. An atom becomes a positively charged ion when it loses an electron and similarly an atom becomes a negatively charged ion when it gains an electron.
Atoms can have loosely bound electrons in their outermost orbits. These electrons require a tiny measure of energy to segregate themselves from their parent particles These electrons are called free electrons which move haphazardly inside the material and move starting with one iota then onto the next.a piece of matter that has an overall unequal number of electrons and protons is called an electrical charge. When the number of electrons is more than its protons, the substance is called negatively charged and when it has more protons than electrons, the substance is said to be positively charged. the substance is said to be positively charged.