# Topic Questions: 111 understand what is meant by nucleon number (mass number) and proton number (atomic number) — WPH14 Nuclear and Particle Physics > 14 WPH14 Nuclear and Particle Physics topic questions (17 marks) on 111 understand what is meant by nucleon number… — 14 papers, 2020–2026. Open the exact… - Canonical HTML: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/111-understand-what-is-meant-by-nucleon-number-mass-number-and-proton-number-atomic/ - Markdown mirror: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/111-understand-what-is-meant-by-nucleon-number-mass-number-and-proton-number-atomic/index.md --- Edexcel IAL · Physics · WPH14 · Nuclear and Particle Physics 14 WPH14 Nuclear and Particle Physics topic questions are tagged to this syllabus point across 14 papers (2020–2026). Only the parts whose knowledge graph matches this syllabus statement are counted, and the table shows which parts of each question are involved. - 14 topic questions - 14 papers - 17 tagged marks - 5.0% of topic questions - 2.6% of topic marks - 2020–2026 - Syllabus 2018–current - [All WPH14 Nuclear and Particle Physics topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/) - [All paper codes](https://www.examsci.com/topics/) Core finding **This Nuclear and Particle Physics syllabus point appears in 14 WPH14 papers across 2020–2026, contributing 14 topic questions and 17 marks.** The most recent appearance is WPH14/01 January 2026. That equals 5.0% of the 278 topic questions and 2.6% of the 656 marks tagged to Nuclear and Particle Physics. Only parts tagged to this subtopic are counted, so a four-part question can contribute one item and one part's marks. The table lists every matching question, its tagged parts and marks, with a link back to the paper page. Sessions are newest first, so the statement can be traced back through the full paper history. ## Topic questions by session Newest sessions first. Parts and marks count only the parts tagged to this subtopic; “x of y parts” shows how much of the question is tagged elsewhere. Select the paper cell to open the matching question on the paper page, or use **Go to Practice Hub** to answer that exact question in the Interactive Practice Hub. | Paper | Question | Type | Parts | Marks | Difficulty | Practice | | --- | --- | --- | --- | --- | --- | --- | | [**WPH14/01** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2026-january-wph14-01/#q-1) | **Q1** Number of Neutrons and Protons in Gadolinium-150 - Edexcel IAL Physics Unit 4 Jan 2026 Q1 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=07537f0c-01cf-4760-bd10-3eed77f7d0a6&question_id=7b5e1ae3-a7c9-4eab-a592-6c7990821366&source_detail=WPH14%2F01+January+2026) | | [**WPH14/02** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2026-january-wph14-02/#q-17) | **Q17** Alpha Scattering and Electric Potential - Edexcel IAL Physics Jan 2026 Q17 | FRQ | 1 of 3 parts ((b)(i)) | 1 of 7 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ee1f4910-5f08-42aa-b80e-e6f9fada0b73&question_id=f720a085-6763-427a-ae18-b5f6fef92228&source_detail=WPH14%2F02+January+2026) | | [**WPH14/01** October 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2025-october-wph14-01/#q-7) | **Q7** Decay of Carbon-11 by Positron Emission - Edexcel IAL Physics Oct 2025 Q7 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=c925843a-0326-4cc4-a60c-ebad9960c7c0&question_id=90394c34-5bb1-4e97-91eb-a1916b0fc857&source_detail=WPH14%2F01+October+2025) | | [**WPH14/02** October 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2025-october-wph14-02/#q-1) | **Q1** Au Nucleon Counting - Edexcel IAL Physics Oct 2025 Q1 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=19a8118b-74b7-4fe4-9125-57c7428661ba&question_id=65e12d97-48bf-4251-aa64-ec97421b9227&source_detail=WPH14%2F02+October+2025) | | [**WPH14/01** June 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2025-june-wph14-01/#q-1) | **Q1** Nucleon and Proton Number - Edexcel IAL Physics June 2025 Q1 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=3fa77855-5a47-4e9d-9d77-8e6feeafb348&question_id=d425db31-18ea-4d36-8c32-5959f3b27ab0&source_detail=WPH14%2F01+June+2025) | | [**WPH14/01** October 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2024-october-wph14-01/#q-4) | **Q4** Alpha Decay Nucleons - Edexcel IAL Physics Oct 2024 Q4 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=b5bd6e3e-5afd-4869-ad78-ba1875109b46&question_id=b0ed16a9-af58-4c1e-be20-d7460dc68d4f&source_detail=WPH14%2F01+October+2024) | | [**WPH14/01** June 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2024-june-wph14-01/#q-11) | **Q11** Chadwick's Discovery of the Neutron - Edexcel IAL Physics Unit 4 June 2024 Q11 | FRQ | 1 of 2 parts ((a)) | 2 of 4 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=cd6c5948-4054-4ae4-8638-e8fde551f1f4&question_id=16e8bb7d-1336-44a4-879f-4d7ef628ee29&source_detail=WPH14%2F01+June+2024) | | [**WPH14/01** January 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2024-january-wph14-01/#q-1) | **Q1** Neutron Count in Antimony-121 - Edexcel IAL Physics Jan 2024 Q1 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=7f671b10-3bb0-47d7-9ab5-58b3498dd1dd&question_id=a8c0fc90-deb0-4215-aa9c-e989d1b8010c&source_detail=WPH14%2F01+January+2024) | | [**WPH14/01** October 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2023-october-wph14-01/#q-1) | **Q1** Isotope Representation - Edexcel IAL Physics Oct 2023 Q1 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=63cf6d9e-c5b2-42b1-b898-7773fe6081a7&question_id=b23472b3-919b-4700-b5f1-95d770899f19&source_detail=WPH14%2F01+October+2023) | | [**WPH14/01** June 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2023-june-wph14-01/#q-3) | **Q3** Beta Plus Decay - Edexcel IAL Physics June 2023 Q3 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=2055a28e-816f-4ab5-8253-c37cfd7dd7b9&question_id=5d593244-a1cd-4e6f-bbd0-7b6257fa8202&source_detail=WPH14%2F01+June+2023) | | [**WPH14/01** January 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2023-january-wph14-01/#q-3) | **Q3** Nucleon Structure after Alpha Decay - Edexcel IAL Physics Jan 2023 Q3 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=495cc00c-1d7f-4297-981d-c1c626ca134d&question_id=fbc00025-bc34-4f00-a7ae-9a0af8f5a8fd&source_detail=WPH14%2F01+January+2023) | | [**WPH14/01** January 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2022-january-wph14-01/#q-1) | **Q1** Nucleon and Neutron Calculation - Edexcel IAL Physics Jan 2022 Q1 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=49fe32a1-ed2d-43cb-8e5c-01ad7a065d74&question_id=fac12707-cdd3-4451-9081-5244362aac1b&source_detail=WPH14%2F01+January+2022) | | [**WPH14/01** January 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2021-january-wph14-01/#q-3) | **Q3** Proton and Neutron Number of Oganesson - Edexcel IAL Physics Jan 2021 Q3 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=ad4d3bdd-35e1-4b4e-8408-0afd068c0d8f&question_id=7d37a0bb-ed07-4c6c-bdaf-cbf910f66609&source_detail=WPH14%2F01+January+2021) | | [**WPH14/01** January 2020 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-4-wph14/2020-january-wph14-01/#q-11) | **Q11** Nuclear Synthesis of Technetium - Edexcel IAL Physics Jan 2020 Q11 | FRQ | 1 part | 3 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=5ef0bb69-523b-4ef4-b94b-964485f16e14&question_id=74fccec1-6afa-4bc9-9e26-eba924ce0938&source_detail=WPH14%2F01+January+2020) | ## Related topic questions in Nuclear and Particle Physics - [112 understand how large-angle alpha particle scattering gives evidence for a nuclear model of the atom and how our understanding of atomic structure has changed over time](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/112-understand-how-large-angle-alpha-particle-scattering-gives-evidence-for-a-nuclear/) — 29 question items · 20 papers — 76 marks · 2020–2026 - [113 understand that electrons are released in the process of thermionic emission and how they can be accelerated by electric and magnetic fields](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/113-understand-that-electrons-are-released-in-the-process-of-thermionic-emission-and/) — 27 question items · 17 papers — 65 marks · 2020–2026 - [114 understand the role of electric and magnetic fields in particle accelerators (linac and cyclotron) and detectors (general principles of ionisation and deflection only)](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/114-understand-the-role-of-electric-and-magnetic-fields-in-particle-accelerators/) — 37 question items · 19 papers — 100 marks · 2020–2026 - [115 be able to derive and use the equation $r=\frac{p}{BQ}$ for a charged particle in a magnetic field](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/115-be-able-to-derive-and-use-the-equation-r-frac-p-bq-for-a-charged-particle-in-a/) — 31 question items · 19 papers — 91 marks · 2020–2026 - [116 be able to apply conservation of charge, energy and momentum to interactions between particles and interpret particle tracks](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/116-be-able-to-apply-conservation-of-charge-energy-and-momentum-to-interactions/) — 27 question items · 15 papers — 89 marks · 2020–2026 - [117 understand why high energies are required to investigate the structure of nucleons](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/117-understand-why-high-energies-are-required-to-investigate-the-structure-of-nucleons/) — 15 question items · 14 papers — 27 marks · 2020–2026 ## Topic question rules and edge cases **How many topic questions cover this syllabus point?** 14 question stems cover this subtopic across 14 papers, but only 14 tagged parts and 17 marks belong to it. Other parts of the same questions are assessed under different statements and are excluded from this page. **Which papers include this subtopic?** The table lists every matching session from 2020–2026. Each row links to the question anchor on the paper page, where the full paper context and practice entry point are available. **Why can one question appear under several subtopics?** The parts of one question can assess different syllabus statements. Each part is counted under its own subtopics, so the same question stem can appear on several subtopic pages while each page lists only the parts and marks tagged to that statement. **Can I practise these questions with AI marking?** Yes. Open a paper from the table and use the Interactive Practice Hub entry point. The page itself is static HTML so search engines and retrieval agents can read the full question list without executing JavaScript. --- Full page with native tables, bar charts and Practice Hub links: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-4-wph14/nuclear-and-particle-physics/111-understand-what-is-meant-by-nucleon-number-mass-number-and-proton-number-atomic/