Quantum Physics - CAIE

Define the photon

Define the photon

A quantum of energy of electromagnetic radiation

What is the photoelectric Effect

An interaction between a photon and an electron in a metal, in which the electron is removed from the surface of the metal.

Define the work function

The minimum energy needed by an electron to free itself from the surface of a metal. Work function is a property of the metal.

Define the De Broglie Wavelength

The wavelength associated with a moving particle

Explain why the maximum kinetic energy of the electron emitted from a metal surface is independent of the intensity of the incident electromagnetic radiation. [3 marks]

• The frequency of a photon determines its energy.

• The intensity of light determines the number of photons per unit time.

• The intensity of light does not determine the energy of a photon.

• The kinetic energy of an electron depends on the energy of one photon.