Electron volt

Definition

An electron volt (eV) is a unit of energy equal to the amount of kinetic energy gained or lost by an electron when it moves through an electric potential difference of one volt. It is commonly used in atomic and particle physics.

5 Must Know Facts For Your Next Test

1. 1 eV equals $1.602 \times 10^{-19}$ joules.
2. Electron volts are often used to measure the energy levels of electrons in atoms.
3. In particle physics, eV, keV, MeV, GeV, and TeV are used to describe the energies of particles.
4. The concept of the electron volt helps simplify calculations involving very small quantities of energy.
5. An electron accelerated through a potential difference of 1 volt gains energy equivalent to 1 eV.

Review Questions

• How much energy in joules is equivalent to 1 electron volt?
• Why are electron volts preferred over joules in atomic and particle physics?
• What happens to an electron's energy when it moves through a potential difference of one volt?

Related terms

Electric Potential Difference:

The work done per unit charge in moving a test charge between two points in an electric field.

Potential Energy:

The energy possessed by an object due to its position relative to other objects; in electricity, it's related to the position within an electric field.

Joule:

The SI unit of work or energy, defined as the work done when a force of one newton displaces a mass by one meter along the direction of the force.