Coulomb`s law is a law of physics that describes the interaction between electrically charged objects. This law states that the electrostatic force between two objects is proportional to the product of the charge of each of the objects and inversely proportional to the square of the distance between these two objects. Coulomb, unit of electric charge in the meter-kilogram-second-ampere system, the basis of the SI system of physical units. It is abbreviated to C. Coulomb is defined as the amount of current that is transported in one second by a current of one ampere. Named after the French physicist Charles-Augustin de Coulomb of the 18th and 19th centuries, it corresponds to about 6.24 × 1018 electrons, with the charge of an electron, the elementary charge, defined as 1.602176634 × 10−19 C. (P.S.S.C.E. 2004, 1999; H.S.S.C.E. 2004, 1996 5.11 The Coulomb is the SIÂ unit of the royalty. The size of a coulomb is derived from the ampere. A coulomb is defined as the amount of charge circulating when the current is 1 ampere.

The SI unit is 6.24 x 10^18 electrons (one coulomb). An electron is marked as q or e – numerically 1.6 x 10^-19 Coulombs.