Section 7.1: Photon Model

The photon model of light explains electromagnetic radiation as consisting of discrete packets of energy called photons. Each photon has energy proportional to its frequency: \[ E = h \nu \] where \( h \) is Planck's constant and \( \nu \) is the frequency of light.

  • Photons carry energy but no charge.
  • Light exhibits both wave-like and particle-like properties.
  • The photon concept explains phenomena like blackbody radiation and the photoelectric effect.

Example: Photon Energy Calculation

Calculate the energy of a photon with frequency \(6.0 \times 10^{14} \, \text{Hz}\).

\( E = h \nu = 6.626 \times 10^{-34} \times 6.0 \times 10^{14} \approx 3.98 \times 10^{-19} \, \text{J} \)

Practice Problems

  1. Calculate the energy of a photon with wavelength 500 nm.
  2. Determine the frequency of a photon with energy \(4.0 \times 10^{-19} \, \text{J}\).
  3. Explain why light must be considered as both a wave and a particle.
  4. Calculate the number of photons emitted per second by a 2 W light source of wavelength 600 nm.
  5. Discuss the significance of Planck's constant in the photon model of light.