This how it works covers How It Works: Why Higher Frequency Means More Danger within Electromagnetic Spectrum for GCSE Physics. Revise Electromagnetic Spectrum in Waves for GCSE Physics with 17 exam-style questions and 15 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 6 of 13 in this topic. Use this how it works to connect the idea to the wider topic before moving on to questions and flashcards.
⚙️ How It Works: Why Higher Frequency Means More Danger
The energy carried by an EM wave is directly proportional to its frequency (E ∝ f). Radio waves have such low frequency that their energy passes harmlessly through most materials. Gamma rays have such high frequency that a single photon carries enough energy to knock electrons out of atoms — this is called ionisation.
Ionising radiation damages DNA by breaking chemical bonds in the double helix. A single broken bond can cause a mutation. If cells with mutations reproduce uncontrollably, this becomes cancer. This is why UV, X-rays, and gamma rays all have cancer risk, but radio waves and microwaves do not cause cancer in the same way (though microwaves can cause heating).
Practice questions for Electromagnetic Spectrum
What is the speed of all electromagnetic waves in a vacuum?
Explain the potential dangers of ultraviolet radiation to humans.