Note – Electric current is the movement of electrons through a wire. Electric current is measured in amperes (amps) and refers to the number of charges that move through the wire per second. ..Voltage is sometimes called electric potential and is measured in volts.
ammeter: An instrument used to measure the electric current in a circuit; the unit of measurement is amperes or amps (A). circuit: A path for electric current to flow. conductor: A substance made up of atoms which hold electrons loosely, allowing them to move through it more easily. electric current: A continuous flow of electric charge moving from one place to another along a pathway; required to make all electrical devices work; measured in amperes or amps (A). electrochemical reaction: A reaction that most often involves the transfer of electrons between two substances, either caused by or accompanied by an electric current. electrode: A conductor through which a current enters or leaves an object or substance. electron: A subatomic particle that has a negative electrical charge. insulator: A substance made up of atoms that hold onto electrons very tightly, thus not allowing electrons to move through very easily. parallel circuit: A type of circuit that allows current to flow through parallel paths. Electric current is split between the different paths. If light bulbs are connected in a parallel circuit, and one of the bulbs is removed, the current will still be able to flow to light the other bulbs in the circuit. semiconductor: A substance made up of atoms that hold onto electrons with a strength between that of a conductor and that of an insulator. series circuit: A circuit in which all of the components are connected along a single path, so that the same current flows through all of the components. If one of the light bulbs is removed, the circuit is broken and none of the other lights will work. voltage: The potential difference between two points in a circuit, such as the positive and negative ends of a battery. It is often described as the “push” or “force” of the electricity. It is possible to have voltage without current (if the circuit is incomplete, for example, and the electrons cannot flow), but not possible to have a current without voltage. It is measured in volts (V). voltmeter: An instrument used to measure the potential electric difference between two points in a circuit.