free electron

noun

, Physics.

1. an electron that is not attached to an atom or molecule and is free to respond to outside forces.

free electron

noun

1. any electron that is not attached to an ion, atom, or molecule and is free to move under the influence of an applied electric or magnetic field

Word History and Origins

Origin of free electron¹

First recorded in 1905–10

Example Sentences

Semiconductors lie between metals, with many free electrons that carry electrical current, and insulators, whose electrons are held within its atoms and cannot form a current.

From Nautilus

The secret was that near absolute zero, vibrations in a metal’s atomic lattice steer free electrons into pairs.

From Quanta Magazine