Unit 15 · Modern Physics

Chapter 15.1

Light Comes in Lumps: Blackbody Radiation and the Photoelectric Effect

A hot poker glows red, then orange, then white, and a dim ultraviolet lamp kicks electrons out of a metal that a blinding red floodlight cannot touch. Neither fact makes sense if light is only a wave.

in preparation · lesson 24 of 27

By the end

  1. 01Describe a blackbody's continuous spectrum and use Wien's law and the Stefan–Boltzmann law
  2. 02Explain why a threshold frequency exists and why brighter light does not eject faster electrons
  3. 03Compute the maximum kinetic energy of ejected electrons from the frequency and the work function
  4. 04Describe the stopping-potential measurement

In unit 15

  1. 15.1Light Comes in Lumps: Blackbody Radiation and the Photoelectric Effect
  2. 15.2Photons, Compton Scattering, and Matter Waves
  3. 15.3The Bohr Atom and Spectra
  4. 15.4The Nucleus: Radioactive Decay, Fission, and Fusion
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