On the quantum level the SI unit the joule is huge so a smaller unit of energy is needed. One electron volt is the energy transferred to or from an electronwhen it moves through a potential difference of 1 volt.since W = QV = eV = 1.6 x 10-19 J. A typical infra-red photon has an energy of about 1.5eV, which is equivalent to one electron travelling through a p.d. of 1.5V.
The Electron Volt
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Specification: OCR Physics A (H156), AS-level, 4.5.1 Photons. Topic: Quantum Physics.
Key terms in this lesson
- random error
- An error that causes repeated readings to vary unpredictably above and below the true value.
- systematic error
- An error that shifts every reading from the true value by the same amount or proportion, in the same direction.
More in Quantum Physics
- The Energy of a Photon and the Planck Constant
- The Photoelectric Effect
- The Photoelectric Effect Equation and Wave-Particle Duality
All 4 lessons in Quantum Physics · All OCR AS-level Physics topics