This key facts covers Key Facts within Background Radiation for GCSE Physics. Revise Background Radiation in Extra Topics for GCSE Physics with 13 exam-style questions and 12 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 7 of 12 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 7 of 12
Practice
13 questions
Recall
12 flashcards
📋 Key Facts
- Background radiation is always present and must be subtracted in experiments
- Corrected count rate = Measured count rate − Background count rate
- Radon gas from rocks is the biggest source (~50% of UK background radiation)
- The UK average annual radiation dose is about 2.7 mSv
- Natural sources contribute about 85% of UK background radiation
- Medical sources are the largest artificial contributor (~14%)
- Nuclear power contributes less than 0.1% — often incorrectly thought to be a major source
- Background radiation is random — readings vary from moment to moment
- Higher altitude = more cosmic radiation (less atmospheric shielding)
- Granite rock areas (e.g. Cornwall) have higher background radiation due to radon