1. A stable elementary particle that is a primary constituent of ordinary matter, contained in the atoms of all elements.

Electrons flowing in a conductor constitute an electric current.

2. A negative beta particle emitted from a radioactive substance.
3. A negatively charged elementary particle that has a specific charge, mass, and spin.

The number of electrons associated with the nucleus of an atom is equal to the atomic number of the substance.

4. A sub-atomic particle with a negative beta particle emitted from a radioactive substance.

A flow of electrical current consi that are in a given material, the greater its electrical conductance (or equivalently, the lower its resistance).

Electrons are the primary charge carriers in electric currents.

All atoms have electrons arranged around a nucleus and an electron may be positive (positron), but as the term is generally used, it refers to the negative form (negatron).

An electrode consisting of two insulated wires inside a single cylinder with neither one acting as the reference electrode.

Variations in voltage can be noted between the areas that the wires touch.