Atoms are the building blocks of all matter. They are made up of protons, neutrons, and electrons. Every electron has a small negative (-) charge. The proton has the same amount of charge except that it is the opposite, positive (+) charge. Neutrons are electrically neutral and have no charge. The protons and neutrons are located in the center of atoms forming what is called the nucleus and the electrons revolve around them.

It is very important to know that particles of like charges will repel and unlike charges will attract. For example, two protons or two electrons will repel each other. However, a proton and a electron will attract. That is how the electrons are held inside the atom. The attraction between the electrons and protons keeps the electrons in orbit much like the gravitational attraction between the sun and its planets.

Electricity is the flow of electrons so it is necessary to measure the charge. The basic unit for measuring charge is the coulomb or the letter C. 1 coulomb is equal to the charge of 6,250,000,000,000,000,000 electrons!!!

1C = 6.25x10^18 electrons