Electric current can mean, depending on the context, a flow of electric charge (a phenomenon) or the rate of flow of electric charge (a quantity). The electric charge that flows is carried by, for example, mobile electrons in a conductor, ions in an electrolyte or both in a plasma.
The SI unit for rate of flow of electric charge is the ampere. Electric current is measured using an ammeter.
A solid conductive metal contains mobile, or free, electr...
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Electric current can mean, depending on the context, a flow of electric charge (a phenomenon) or the rate of flow of electric charge (a quantity). The electric charge that flows is carried by, for example, mobile electrons in a conductor, ions in an electrolyte or both in a plasma.
The SI unit for rate of flow of electric charge is the ampere. Electric current is measured using an ammeter.
A solid conductive metal contains mobile, or free, electrons. These electrons are bound to the metal lattice but not to any individual atom. Even with no external electric field applied, these electrons move about randomly due to thermal energy but, on average, there is zero net current within the metal. Given a plane through which the wire passes, the number of electrons moving from one side to the other in any period of time is on average equal to the number passing in the opposite direction. As George Gamow put in his science popularizing book, One, Two, Three...Infinity (1947), "The metallic...
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