The electron volt (eV) is the energy associated with accelerating one electron through a potential difference of 1 volt. Accelerate an electron from rest through a potential difference of 500 volts, and its kinetic energy will be 500 eV.
1 eV = 1.60 x 10-19 J
Use the equations c = fl and E = hf to determine the frequency and energy for photons in the visible spectrum.
| Wavelength | Frequency | Energy |
|---|---|---|
| 400 nm (violet) | 7.5 x 1014 Hz | 3.11 eV |
| 700 nm (red) | 4.3 x 1014 Hz | 1.78 eV |