Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can list the regions of the electromagnetic spectrum in order of wavelength and of photon energy. (Guide: “The electromagnetic spectrum”; Practice Q1)
- I can explain why a shorter wavelength means a more energetic photon. (Guide: “Light is a stream of energy packets”; Practice Q6)
- I can describe the three ways a molecule stores energy: rotation, vibration and electron arrangement. (Guide: “Three ways a molecule stores energy”)
- I can state that rotational gaps are much smaller than vibrational gaps, which are much smaller than electronic gaps. (Guide: Figure 2)
Skills
- I can match microwave radiation to rotational transitions, infrared to vibrational transitions, and ultraviolet or visible radiation to electronic transitions. (Practice Q2)
- I can convert wavelengths given in mm, μm and nm to metres before comparing them. (Guide: Worked example 1; Practice Q3)
- I can assign a set of absorption wavelengths to regions and transition types and rank the energy gaps. (Practice Q4)
- I can explain why a single atom shows only electronic transitions, while a molecule can also absorb microwaves and infrared. (Guide: Worked example 2)
Reasoning
- I can explain a solution’s colour as the light left after an electronic absorption, and explain why a substance that absorbs only in the ultraviolet is colourless. (Practice Q5)
- I can evaluate a claim about which radiation can break a bond, using photon energies and bond energies. (Practice Q6)
- I can explain why a gas absorbs infrared but lets visible light through, using the idea that a photon must match a gap. (Practice Q7)
All ticked? Move on to Topic 3.12, Properties of Photons, or return to the course roadmap.