6.4.1—Solar radiation spectrum
- Syllabus
- First assessment 2026
- Objective
- 6.4.1
- Level
- HL
Use Wavelength to Order Radiation Energy
Solar electromagnetic radiation spans low-frequency radio waves through infrared, visible light and ultraviolet to high-frequency gamma radiation; shorter wavelength means higher frequency and photon energy.
Infrared transfers heat, visible light powers photosynthesis and supports vision, and ultraviolet can drive atmospheric chemistry but damage biological molecules at higher-energy bands.
UV-C has shorter wavelength and higher photon energy than visible red light.
Order by wavelength or frequency, then identify the biosphere process that actually absorbs or uses each band.
Brighter light is not automatically higher-energy light per photon.