experiment 047 · quantum mechanics
The Photoelectric Effect
Light shines on a metal plate, emitting electrons only if the light's frequency is high enough. This demonstrates the particle nature of light, where energy is delivered in discrete packets called photons.
The Mathematics
The energy of a photon is proportional to its frequency: $E = hf = \frac{hc}{\lambda}$. An electron is only emitted if this energy exceeds the material's work function ($\Phi$).
If the photon energy $\frac{hc}{\lambda}$ is less than $\Phi$, no electrons are emitted regardless of the light intensity.
Read the full article: The Photoelectric Effect