PhotoElectric Effect 2

What does the Photoelectric Effect tell us about the nature of light?
(What is the significance of the photoelectric effect?)

The photoelectric effect:
  1. confirms that light has a particle nature.
  2. establishes the quantum theory (light energy is quantized)

Terminology

Work Function W0:
minimum amount of energy required to remove an electron from the surface of a substance

Threshold Frequency f0:
lowest frequency of light that can cause ejection of electrons from a substance

Quanta:
Photons:

Photoelectrons:
electrons that are ejected from the metal


The PHOTO ELECTRIC EFFECT shows that light has a PARTICLE NATURE

DUAL NATURE of LIGHT
Since light can behave both as a particle or as a wave, it is said that light has a dual nature.
(dual means 2)
It is said that light travels as a wave, but interacts as a particle when it strikes a substance.





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