An electron-volt (eV) is a unit of energy equal to approximately 1.602176634 × 10⁻¹⁹ joules. It represents the amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt in vacuum.
A joule (J) is the derived unit of energy in the International System of Units (SI). It is equal to the energy transferred to an object when a force of one newton acts on that object in the direction of the force's motion through a distance of one meter.
| Electron-volts (eV) | Joules (J) |
|---|---|
| 1 eV | 1.602176634 × 10⁻¹⁹ J |
| 1 keV | 1.602176634 × 10⁻¹⁶ J |
| 1 MeV | 1.602176634 × 10⁻¹³ J |
| 1 GeV | 1.602176634 × 10⁻¹⁰ J |
| 1 TeV | 1.602176634 × 10⁻⁷ J |
To convert electron-volts to joules, multiply the eV value by 1.602176634 × 10⁻¹⁹. This conversion factor represents the exact relationship between the two units.
Let's convert 5 eV to joules:
5 eV = 5 × (1.602176634 × 10⁻¹⁹) J
5 eV = 8.01088317 × 10⁻¹⁹ J
Electron-volts are commonly used in: