This definitions covers Key Terms 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 6 of 12 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 6 of 12
Practice
13 questions
Recall
12 flashcards
📖 Key Terms
- Background radiation
- The low-level ionising radiation that is always present in the environment, coming from both natural and artificial sources. It must be measured and subtracted when making radioactivity measurements.
- Count rate
- The number of nuclear decay events detected per unit time (per minute or per second). Measured using a Geiger-Muller (GM) tube and counter.
- Corrected count rate
- The count rate from a source alone, calculated by subtracting the background count rate from the measured count rate.
- Radon gas
- A naturally occurring radioactive gas produced by the decay of uranium in rocks and soil. It is the largest single contributor to background radiation and a major source of alpha radiation exposure.
- Cosmic rays
- High-energy particles (mainly protons) from the Sun and other stars that constantly bombard the Earth. Most are absorbed by the atmosphere, but some reach the surface, particularly at high altitude.
- Dose
- A measure of the energy deposited by ionising radiation in human tissue. Measured in sieverts (Sv) or millisieverts (mSv). Takes into account both the amount of radiation and how damaging it is to tissue.