Electronvolt
Contents
Key Stage 5
Meaning
An electronvolt (eV) is a unit of energy defined as the energy required to accelerate an electron across a potential difference of one volt.
About the Electronvolt
- The electronvolt is denoted with a lower case 'e' followed by an upper case 'V'.
- The electronvolt is equal to 1.60x10-19 Joules (correct to 3 significant figures).
- Since the equation linking Energy (E), charge (q) and potential difference (V) is \(E=qV\), then, considering the charge on an electron is the magnitude of the elementary charge and its energy having been accelerated through a potential difference of 1 volt we can define the energy of a subatomic particle in integers of the elementary charge \(E=eV\) where e is the magnitude of the elementary charge.
Unit Comparisons
| Unit 1 | Unit 2 |
| 1 Electronvolt | 1.60x10-19Joule |
| 1 Joule | 6.25x1018eV |
Converting to Electronvolts
| Unit | To convert | Electronvolts |
| 1 Gigaelectronvolt (1GeV) | Convert to Electronvolts x1000,000,000. | 1000,000,000eV |
| 1 Megaelectronvolt (1MeV) | Convert to Electronvolts x1000,000. | 1000,000eV |
| 1 kiloelectronvolt (1keV) | Convert to Electronvolts x1000. | 1000eV |
| 1 Electronvolt (1eV) | Convert to Electronvolts x1. | 1eV |
| 1 millielectronvolt 1(meV) | Convert to Electronvolts /1000. | 0.001eV |
| 1 microelectronvolt 1(µeV) | Convert to Electronvolts /1000,000. | 0.000001eV |