A coulomb is defined as the charge transferred by a current of 1 ampere in one second. A coulomb is a quantity measurement with regard to electrons. One coulomb consists of 6.25 X 1018, or 6,250,000,000,000,000,000 electrons. To help understand the quantity of electrons contained in a coulomb, think of comparing one second to 200 billion years. Considering that the coulomb is a quantity measurement, it is very similar to a quart, a gallon, or a liter. It takes a certain amount of liquid to equal a liter, similar to how it takes a certain number of electrons to equal a coulomb.
The coulomb is named for a French scientist who resided in the 1700s named Charles Augustin de Coulomb. Coulomb researched electrostatic charges and developed a law dealing with the attraction and repulsion of these forces. The law, often known as Coulomb’s law of electrostatic charges, states that the force of electrostatic attraction or repulsion is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them. The number of electrons contained in the coulomb was determined by the average charge of an electron. The symbol for coulomb is the letter C. It is the System Internationale (SI) unit of electric charge.