AQA GCSE Physics Physics Paper 1 (Foundation), June 2022: Question 4
12 marks · Standard Demand difficulty · Short Answer
Identify properties and nuclear equations of alpha, beta, and gamma radiation, complete penetration and ionising power tasks, and calculate background radiation dose ratios.
Practise this questionQuestion
Question text
04 Radioactive isotopes emit different types of nuclear radiation.
04.1 What does an alpha particle consist of?
[1 mark]
Tick ( ) one box.
2 protons and 2 electrons
2 protons and 2 neutrons
4 protons
4 neutrons
04.2 What is a beta particle?
[1 mark]
Tick ( ) one box.
An electron
A neutron
Electromagnetic radiation
04.3 A krypton (Kr) nucleus decays into a rubidium (Rb) nucleus by emitting a beta particle.
What is the correct equation for this decay?
[1 mark]
Tick ( ) one box.
04.4 Figure 5 shows an experiment to demonstrate how alpha, beta and gamma radiation
penetrate different materials.
*11* The experiment takes place in a vacuum.
Figure 5
Three different materials are used:
• a sheet of paper
• a 0.5 cm thick sheet of aluminium
• a 10 cm block of lead.
Each material is placed one at a time between the radioactive source and the
GM tube.
The GM tube and counter show whether the material has stopped the radiation.
Complete Table 1 to show how alpha, beta and gamma radiation penetrate the
materials in Figure 5.
Use the words Yes and No.
Part of Table 1 has been completed for you.
[3 marks]
Table 1
Most radiation is stopped by:
Type of
radiation the sheet of
the sheet of paper the block of lead
aluminium
Alpha Yes
Beta No
Gamma 13 No
04.5 Alpha, beta and gamma radiation have different ionising powers.
Draw one line from each radiation type to the correct ionising power.
*12* [3 marks]
04.6 Some sources of background radiation are natural and other sources are man-made.
Which of the following is a man-made source of background radiation?
[1 mark]
Tick ( ) one box.
Cosmic rays
Nuclear accidents
Rocks
04.7 The average background radiation dose per year in the UK is 2.0 millisieverts.
A dental X-ray gives a patient a radiation dose of 0.005 millisieverts.
Calculate how many dental X-rays would be the same as the average background
radiation dose per year.
[2 marks]
Number of dental X-rays =
Mark scheme
Show the mark scheme
Question 4
AO /
Question Answers Extra information Mark
Spec. Ref.
04.1 2 protons and 2 neutrons 1 AO1
4.4.2.1
AO /
Spec. Ref.
04.2 an electron 1 AO1
4.4.2.1
AO /
Spec. Ref.
04.3 1 AO1
4.4.2.2
AO /
Spec. Ref.
04.4 3 AO1
4.4.2.1
1 mark for each correct row
allow ticks and crosses in place of yes and no
any incorrect answer on a row negates the mark for the row–HYSICS – –
AO /
Spec. Ref.
04.5 AO1
1 4.4.2.1
1 mark for each correct line
if more than one line drawn from radiation type list principle applies
AO /
Spec. Ref.
04.6 nuclear accidents 1 AO1
4.4.3.1
AO /
Spec. Ref.
04.7 2.0 1 AO2
number = 4.4.3.1
0.005
number = 400 1
Total Question 4 12
How to answer it
Radioactive Isotopes and Nuclear Radiation
This question assesses your knowledge of nuclear physics (AQA GCSE 4.4). Key areas tested include the composition and properties of alpha and beta particles, nuclear decay equations, the penetrating power of different types of radiation, ionising power, sources of background radiation, and basic calculations involving radiation dosage.
Alpha Particle Composition
✅ Correct Answer
2 protons and 2 neutrons (Tick the second box)
💡 Key Knowledge
- An alpha particle is identical to a helium nucleus ( ⁴₂He ).
- It has a relative mass of 4 and a charge of +2.
Beta Particle Definition
✅ Correct Answer
An electron (Tick the first box)
💡 Key Knowledge
- A beta-minus particle is a high-speed electron ejected from the nucleus when a neutron turns into a proton.
Beta Decay Equation
✅ Correct Answer
⁸⁵₃₆Kr → ⁸⁵₃₇Rb + ⁰₋₁e (Tick the middle box)
🧠 Exam Technique
Check that mass numbers (top numbers) and atomic numbers (bottom numbers) balance on both sides of the arrow:
- Mass numbers: 85 = 85 + 0 (Balanced)
- Atomic numbers: 36 = 37 + (-1) (Balanced)
Penetrating Power of Radiation
✅ Correct Answer - Completed Table
- Alpha: Paper = Yes | Aluminium = Yes | Lead = Yes
- Beta: Paper = No | Aluminium = Yes | Lead = Yes
- Gamma: Paper = No | Aluminium = No | Lead = Yes
❌ Common Errors
Students often misunderstand the table structure. If a material stops a radiation type, then all subsequent thicker/stronger materials will also stop it. Therefore, alpha is stopped by paper, aluminium, and lead.
Ionising Powers
✅ Correct Answer (Matching Lines)
- Alpha → High
- Beta → Medium
- Gamma → Low
💡 Key Knowledge
Ionising power is inversely related to penetrating power. Alpha particles are large and heavily charged, making them very strongly ionising but easily blocked. Gamma rays have weak ionising power but high penetration.
Man-Made Background Radiation
✅ Correct Answer
Nuclear accidents (Tick the middle box)
💡 Key Knowledge
- Natural sources: Cosmic rays, rocks (radon gas), food, and living things.
- Man-made sources: Medical X-rays, fallout from nuclear weapons testing, and nuclear accidents (e.g., Chernobyl).
Radiation Dose Calculation
📐 Step-by-Step Calculation
- Identify the formula needed:
Number of X-rays = Total annual dose / Dose per X-ray - Substitute the values:
Number = 2.0 / 0.005 - Calculate the final answer:
400
❌ Common Errors & Traps
Inverting the fraction ( 0.005 / 2.0 ) is a frequent mistake made under exam pressure. Always check if your final answer makes logical sense (i.e., a very small dose from a dental X-ray should go into the yearly background dose many times over).
Topics
Physics · P4: Atomic Structure
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Foundation), June 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.