Electricity is the flow of:

• A. Protons
• B. Electrons
• C. Neutrons
• D. Photons

Answer: (B)

Electricity in a conductor is the flow of electrons. In metals, electrons aren’t tightly bound to individual atoms; they form a loose “sea” that can move when a voltage is applied. This drift of electrons constitutes the electric current. Protons stay bound in atomic nuclei and don’t flow through a metal, so they don’t carry the current. Neutrons have no electric charge, so they don’t participate in electrical flow. Photons carry energy and can power electromagnetic waves or light, but they aren’t the moving charges that make up a typical electrical current in a circuit. (In circuits, conventional current is defined as the direction of positive charge flow, which is opposite to the actual motion of electrons in metals.)