Electricity
Electricity is the flow of electrons. To understand electricity we need to look at atoms. Atoms have a nucleus that contains protons (positive charged particles) and neutrons (neutral particles). Atoms also have electrons (negative charged particles) that zip around the nucleus in orbitals (circles around the nucleus). Because each atom normally has an equal number of protons and electrons, the atom is electrically neutral. But if there is an imbalance in the numbers, the atom is considered to be electrically charged.
An imbalance occurs when electrons are added or removed from an orbital of an atom. The electrons from these atoms will naturally flow from areas of more energy to areas of less energy forming an electric current. Electrical currents run in closed pathways called circuits from an area of high energy to an area of low energy. Along that circuit you can have appliances, lights, sockets, etc., which tap into the flow of electricity.
Direct Current (DC) vs. Alternating Current (AC)
Direct current (DC) is electricity where the electrons are flowing in one direction only. A battery in which electrons flow from a positive terminal to a negative terminal is an example. The power that comes into your home or business, however, is alternating current (AC). AC electricity changes direction in a back-and-forth cycle. This back and forth cycle is called the frequency. The frequency is measured in Hertz. (Hertz are named after Heinrich Hertz (1857-1894), a German physicist who studied electromagnetic radiation.) Power in the United States is designated as 60 Hertz (60Hz) or 60 cycles a second. A major advantage of alternating current is that the voltage can be increased and decreased by a transformer for more efficient transmission over long distances.
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