Pearson Edexcel International GCSE in Physics · 4PH1 · Free · no account needed
Nuclear Equations — exam questions
11 original Incandio exam-style questions on Nuclear Equations, 26 marks, about 26 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for Nuclear Equations — the lesson that teaches it. Read the lesson first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
7 command words run through this set, and on Pearson Edexcel International GCSE Physics each one means something precise. Answering the wrong command is the commonest way a candidate who understands the lesson still loses the mark.
- Which (1 mark)
- one option chosen from the set given
- State (1 mark)
- one precise fact or definition
- Complete (1–4 marks)
- the missing entries in a table, circuit or diagram
- Determine (1–4 marks)
- a value obtained by combining a reading or gradient with a relationship
- Explain (2–4 marks)
- the physics that causes it, set out as a line of reasoning Misread as: describing the change without giving the physical reason for it
- Suggest (1–3 marks)
- a plausible answer applying taught physics to an unfamiliar arrangement
- Identify (1–2 marks)
- the correct item selected from what is shown
Assessed on Paper 1 (4PH1/1P) and Paper 2 (4PH1/2P), against AO1, AO2, AO3.
Where these sit in the specification
Pearson Edexcel International GCSE Physics (4PH1) — statements 7.7 · 7.8. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 11 questions
Answer them on paper, then open the lesson's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
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A radioactive nucleus of thorium-232 decays through a sequence of steps before eventually becoming a stable isotope of lead. A physicist recorded the mass number and atomic number of the first four nuclei in the sequence.
Table 1 — the first four nuclei in the thorium-232 series Step Mass number Atomic number 1 (thorium) 232 90 2 (radium) 228 88 3 (actinium) 228 89 4 (thorium again) 228 90 (a)
(1)Identify
Identify the type of decay in the first step of Table 1.
A radioactive nucleus of thorium-232 decays through a sequence of steps before eventually becoming a stable isotope of lead. A physicist recorded the mass number and atomic number of the first four nuclei in the sequence.
Table 1 — the first four nuclei in the thorium-232 series Step Mass number Atomic number 1 (thorium) 232 90 2 (radium) 228 88 3 (actinium) 228 89 4 (thorium again) 228 90 (b)
(3)Explain
Explain how Table 1 shows that steps 2 and 3 are both beta decays.
A radioactive nucleus of thorium-232 decays through a sequence of steps before eventually becoming a stable isotope of lead. A physicist recorded the mass number and atomic number of the first four nuclei in the sequence.
Table 1 — the first four nuclei in the thorium-232 series Step Mass number Atomic number 1 (thorium) 232 90 2 (radium) 228 88 3 (actinium) 228 89 4 (thorium again) 228 90 (c)
(3)Determine
Determine the mass number and atomic number after two further alpha decays from step 4 of Table 1.
A radioactive nucleus of thorium-232 decays through a sequence of steps before eventually becoming a stable isotope of lead. A physicist recorded the mass number and atomic number of the first four nuclei in the sequence.
Table 1 — the first four nuclei in the thorium-232 series Step Mass number Atomic number 1 (thorium) 232 90 2 (radium) 228 88 3 (actinium) 228 89 4 (thorium again) 228 90 (Total for Question 1 = 7 marks)
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(1)Which
Which emission leaves both the mass number and the atomic number unchanged?
Emission A alpha B beta C gamma D a neutron (Total for Question 2 = 1 mark)
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(1)State
State the change in the atomic number of a nucleus when it emits an alpha particle.
(Total for Question 3 = 1 mark)
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(2)Complete
Complete this alpha decay by giving the mass number and atomic number of the nucleus formed: radon-222 has mass number 222 and atomic number 86, and it decays by alpha emission to polonium.
(Total for Question 4 = 2 marks)
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(2)Determine
Carbon-14 has mass number 14 and atomic number 6. It decays by beta emission. Determine the mass number and atomic number of the nucleus produced.
(Total for Question 5 = 2 marks)
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(3)Explain
Explain why the atomic number of a nucleus increases when it emits a beta particle, even though the beta particle is negatively charged.
(Total for Question 6 = 3 marks)
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(3)Determine
A nucleus of mass number 238 and atomic number 92 emits an alpha particle and then two beta particles in turn. Determine the mass number and atomic number of the final nucleus.
(Total for Question 7 = 3 marks)
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(3)Suggest
Suggest what particle X must be, and justify your suggestion from the numbers.
An unfamiliar nuclear reaction — When a nucleus of beryllium-9 (mass number 9, atomic number 4) is struck by an alpha particle, it produces a nucleus of carbon-12 (mass number 12, atomic number 6) and one other particle, X. This reaction was how the particle X was first discovered.
(Total for Question 8 = 3 marks)
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(4)Explain
Explain how the mass number and the atomic number of a nucleus each change during alpha decay and during beta decay.
(Total for Question 9 = 4 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 11 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain Nuclear Equations to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Ernest Rutherford over three rounds, marked against descriptors you can read first.
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Back to the lesson
- Nuclear Equations — What each kind of decay does to the numbers — and why losing a negative particle makes the charge go up.
- All of Incandio Physics · Incandio Exam Practice