Electromagnetic spectrum — Science definition
The full range of EM waves, ordered from long, low-energy radio waves to short, high-energy gamma rays.
Where it is taught
- Light & the Electromagnetic Spectrum — Waves, Sound & Light, Physical Science: Matter, Forces & Energy, Grade 8
- Light & the Electromagnetic Spectrum — Waves, Sound & Optics, Physics & Environmental Science, Grade 12
In use
The electromagnetic spectrum is the full range of EM waves, arranged by wavelength.
Light & the Electromagnetic Spectrum
The electromagnetic spectrum arranges all EM waves by wavelength: from the longest, running through radio waves, microwaves, infrared, the narrow band of visible light our eyes detect, then ultraviolet, X-rays, and finally gamma rays with the shortest wavelengths.
Light & the Electromagnetic Spectrum
Questions using electromagnetic spectrum
Problem 1
Answer and explanation
All are electromagnetic waves, all travel at the same speed in a vacuum, and none needs a medium. They differ in frequency and wavelength, which together determine their energy and therefore how they interact with matter — radio waves pass through walls, visible light reflects off them, and gamma rays penetrate and can damage living tissue.
Response criteria
- State a scientifically accurate conclusion.
- Show the data, mechanism, or calculation that supports it.
- Include units, conditions, or limits where relevant.
Taught alongside
- electromagnetic (EM) wave
- reflection
- absorption
- transmission
- model
- evidence
- system boundary
- assumption
- speed of light (c)
- photon
- wave-particle duality
- Planck's constant (h)