A radioactive source emits alpha particles, beta particles and gamma rays. State the nature (what each type of radiation actually is) of each of these three types of radiation.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (4 marks)
1. Alpha radiation consists of a helium nucleus (two protons and two neutrons).
2. Beta radiation consists of a fast‑moving electron emitted from the nucleus.
3. Gamma radiation is electromagnetic radiation, a high‑frequency electromagnetic wave.
4. Gamma radiation has no mass and carries no charge.
2. Beta radiation consists of a fast‑moving electron emitted from the nucleus.
3. Gamma radiation is electromagnetic radiation, a high‑frequency electromagnetic wave.
4. Gamma radiation has no mass and carries no charge.
Examiner tips
- Use the exact wording from the mark scheme – e.g. "helium nucleus" for alpha. Include the key properties: mass/charge for each type. Keep each point short and separate with numbers or bullets.
Common mistakes
- Confusing alpha particles with protons or neutrons. Calling beta radiation a proton or neutron instead of an electron. Forgetting that gamma rays have no mass or charge. Using vague terms like "light" for gamma radiation.
Mark scheme (4 marks)
- Alpha radiation consists of two protons and two neutrons / a helium nucleus
- Beta radiation consists of a fast-moving electron (emitted from the nucleus)
- Gamma radiation is electromagnetic radiation / a high-frequency electromagnetic wave
- Gamma radiation has no mass and no charge / gamma radiation carries no charge
Key terms in this question
alpha particle · beta particle
Related
- All WJEC GCSE Physics (Wales) revision notes →
- How to answer a "State" question →
- Decode the mark scheme abbreviations →
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