WJEC GCSE Physics
WJEC GCSE Physics 2.7 Types of Radiation Exam Questions
Free WJEC GCSE Physics revision for 2.7 Types of Radiation: what you need to know, common mistakes and exam-style questions with answers. Covers atomic structure, isotopes, alpha, beta and gamma radiation, penetration and ionisation, nuclear equations, background radiation and radioactive waste.
Practise 2.7 Types of Radiation with past papers
Once you have learnt this topic, find the 2.7 Types of Radiation questions in real WJEC GCSE Physics past papers and mark them with the mark scheme. Doing lots of real questions is the quickest way to learn how examiners ask about each idea.
StemUp mark scheme flashcards
GCSE Physics Triple Science Flashcards for 2027 Onwards
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Then test yourself with the questions on this page.
From £7.99View flashcards
About WJEC GCSE Physics 2.7 Types of Radiation
Types of radiation begins the radioactivity section of Unit 2. You need to use nucleon number and proton number, describe isotopes, and explain that unstable nuclei emit alpha particles, beta particles or gamma rays. You must compare their identity, penetrating power and ionising effect, write balanced nuclear equations for alpha and beta decay, and correct for background radiation in measurements. The random nature of decay, the sources of background radiation including radon, and the hazards and storage of radioactive waste are also covered. Examiners regularly set nuclear equations to complete and questions about choosing a suitable type of radiation for a use.
What you need to know
- Nucleus The nucleon number A is the number of protons plus neutrons; the proton number Z is the number of protons. Isotopes of an element have the same Z but a different A. Unstable nuclei decay by emitting radiation.
- Alpha An alpha particle is a helium nucleus (2 protons, 2 neutrons). It is strongly ionising and stopped by paper or a few cm of air. In alpha decay A falls by 4 and Z falls by 2.
- Beta A beta particle is a fast electron emitted from the nucleus when a neutron changes into a proton. It is moderately ionising and stopped by a few mm of aluminium. In beta decay A is unchanged and Z increases by 1.
- Gamma Gamma rays are high frequency electromagnetic waves. They are weakly ionising, very penetrating and reduced by thick lead or concrete. Gamma emission does not change A or Z.
- Background radiation Natural sources include radon gas from rocks, cosmic rays, food and building materials; artificial sources include medical X-rays. Radon levels vary across the UK. Subtract the background count from readings.
- Randomness and waste Decay is random, so repeat readings and take means. Radioactive waste can stay hazardous for a very long time and must be stored securely, shielded and monitored.
Common mistakes in 2.7 Types of Radiation
- Saying gamma rays are the most dangerous in all situations. Inside the body alpha is the most harmful because it is the most ionising; outside, gamma and beta are more hazardous because they can penetrate the skin.
- Changing the nucleon number in beta decay. In beta decay the nucleon number stays the same and the proton number increases by 1.
- Forgetting to subtract background radiation. Corrected count = measured count - background count.
- Calling beta particles electrons from the electron shells. They come from the nucleus when a neutron changes into a proton.
Try three 2.7 Types of Radiation exam-style questions
1. Uranium-238 (Z = 92) decays by alpha emission to thorium (Th). Write the nuclear equation. (2 marks)
Show the mark scheme answer
238/92 U → 234/90 Th + 4/2 He (or α); nucleon and proton numbers correct.
2. A counter records 250 counts per minute near a source. The background count is 30 counts per minute. Calculate the corrected count rate. (1 mark)
Show the mark scheme answer
250 - 30 = 220 counts per minute.
3. Explain which type of radiation is used to detect leaks in underground pipes. (3 marks)
Show the mark scheme answer
Gamma; can penetrate soil to reach the surface detector; a short half-life source is chosen so it does not stay radioactive for long.
2.7 Types of Radiation FAQs
What does WJEC GCSE Physics 2.7 Types of Radiation cover?
It covers nucleon and proton numbers, isotopes, alpha, beta and gamma radiation and their properties, nuclear equations, background radiation including radon, the random nature of decay and radioactive waste.
Which unit is Types of Radiation examined in?
It is examined in Unit 2: Forces, Space and Radioactivity, a 1 hour 45 minute written paper worth 45% of the GCSE, sat at foundation or higher tier. The Unit 3 practical assessment draws on the same practical skills.
How do I balance nuclear equations?
Check that the top numbers (nucleon numbers) and the bottom numbers (proton numbers) add up to the same totals on both sides. Learn alpha as 4/2 He and beta as 0/-1 e.
