Unit 3 · Properties of Substances and Mixtures

Chapter 3.6

Light as a Probe: Spectroscopy, Photons, and the Beer–Lambert Law

A microwave oven, a heat lamp, and a sunburn are the same physics at three energies: light making molecules spin, vibrate, or rearrange their electrons. Shine light through a solution and it even counts the molecules for you.

lesson 14 of 45

By the end

  1. 01Match microwave, infrared, and ultraviolet–visible light to rotational, vibrational, and electronic transitions
  2. 02Relate a photon's energy, frequency, and wavelength with Planck's equation and the speed of light
  3. 03Explain absorption and emission as a transition of exactly one photon's energy
  4. 04Use absorbance, path length, and molar absorptivity to find a concentration

In unit 3

  1. 3.1Intermolecular Forces: Why Molecules Stick Together
  2. 3.2Solids, Liquids, and Gases: Properties from Particles
  3. 3.3The Ideal Gas Law, Kinetic Molecular Theory, and Real Gases
  4. 3.4Solutions and Molarity: Picturing What Is Dissolved
  5. 3.5Separating Mixtures and Why Things Dissolve
  6. 3.6Light as a Probe: Spectroscopy, Photons, and the Beer–Lambert Law
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