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. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. 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.
📖 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.
Practice questions for Background Radiation
What is background radiation?
Describe two natural sources and one artificial source of background radiation.
Quick recall flashcards
What is background radiation?
Low-level radiation that is always present in the environment from natural and artificial sources
What are cosmic rays?
Radiation from space (from exploding stars) that contributes ~10% of background radiation