According to the electron theory, the flow of current is a movement of what?

The correct answer reflects an understanding of how current operates at a fundamental level in electrical circuits. According to the electron theory, electric current is primarily defined as the flow of electrons within a conductive medium, typically through metals. Electrons, which carry a negative charge, move from one atom to another in a conductor under the influence of an electric field.

This movement creates a "current" as electrons flow in a directed manner, essentially comprising the electrical flow we measure. The behavior of electrons in this context is what forms the basis of circuit design and electrical engineering principles, making it critical to comprehend this flow when analyzing electrical systems.

In contrast, protons do not move in this way; they reside in the nucleus of an atom and are not involved in the conduction of electricity. The nucleus itself is stable and does not drift between atoms. Molecules are larger structures that do not participate directly in electrical current flow but instead are composed of atoms and their interacting subatomic particles. Understanding that current is defined specifically by the movement of electrons offers a clear and fundamental insight into the nature of electric flow.