stem/Light.md

E=hf

Photoelectric Effect

• Emission of charged particles when exposed to UV light
• Electrons
• Einstein suggested light is quantised

1. The maximum KE of ejected electrons is independent of intensity, but dependent on frequency n
2. There is a minimum frequency n0below which there is no emission
3. No time delay (less than 1 ns) before the onset of emission –but the rate of electrons depends on the intensity.