← All topics | Atomic structure topic page | Key: C+S = Combined and Separate · S only = Separate only · HT = Higher only | 🔍 = see example pictures (Google Images, SafeSearch on)
✏️ Topic summary – copy into your book
An atom has a tiny, positive nucleus of protons and neutrons, surrounded by electrons in energy levels. Our model of the atom changed as new evidence was found, especially from the alpha scattering experiment. Some nuclei are unstable and decay randomly, giving out alpha, beta or gamma radiation. Half-life is the time for the number of unstable nuclei to halve. Ionising radiation can damage cells, so we must protect against contamination and irradiation. (S only) Radiation has medical uses, and large nuclei can split (fission) while small nuclei can join (fusion), releasing energy.
Lesson 1 – The structure of the atom and isotopes (C+S)
- Read and copy notes: Atoms and Isotopes → “Inside the atom” table and the copy box.
- Copy definitions: Atomic structure topic page → Key definitions → 1 “Atomic number”, 2 “Mass number”, 3 “What are isotopes?” and 4 “What is an ion?”
- Copy worked examples: Atoms and Isotopes → Q3 (protons, neutrons and electrons in carbon-14) and Q10 (how many times bigger the atom is than the nucleus).
- Draw: Key Diagrams: Atomic Structure → diagram 38 (nuclear model) 🔍 and diagram 41 (electron energy levels) 🔍.
- Fill the gaps: Fill the gaps: Atomic Structure → passage 1 (structure of the atom) and passage 2 (atomic number, mass number and isotopes).
- Practise: Atoms and Isotopes → Q1, Q2, Q4, Q8 and Q9.
Lesson 2 – How the model of the atom developed (C+S)
- Read: Atoms and Isotopes → “How the model of the atom developed” and the alpha scattering results.
- Draw: Key Diagrams: Atomic Structure → diagram 39 (plum pudding model) 🔍 and diagram 40 (alpha scattering experiment) 🔍.
- Fill the gaps: Fill the gaps: Atomic Structure → passage 3 (how the model changed) and passage 10 (the alpha scattering experiment).
- Practise: Atoms and Isotopes → Q5, Q6 and Q7.
- Lesson activity: Science Detectives.
Lesson 3 – Radioactive decay and types of radiation (C+S)
- Read and copy notes: Radioactive Decay and Half-life → notes and the alpha/beta/gamma copy box.
- Copy definitions: Atomic structure topic page → Key definitions → 5 “What is radioactive decay?”, 9 “Alpha particle”, 10 “Beta particle”, 11 “Gamma ray” and 12 “What does ionising mean?”
- Draw: Key Diagrams: Atomic Structure → diagram 42 (penetration of alpha, beta and gamma) 🔍.
- Fill the gaps: Fill the gaps: Atomic Structure → passage 4 (types of nuclear radiation).
Lesson 4 – Nuclear equations (C+S)
- Read: Nuclear Decay Equations → the rules for alpha, beta and gamma equations.
- Draw: Key Diagrams: Atomic Structure → diagram 43 (alpha decay equation for radium-226) 🔍. See also 🔍 beta decay equations.
- Fill the gaps: Fill the gaps: Atomic Structure → passage 5 (nuclear equations).
- Practise: all the questions on Nuclear Decay Equations.
Lesson 5 – Activity and half-life (C+S; ratios HT)
- Read: Radioactive Decay and Half-life → the half-life notes.
- Copy definitions: Atomic structure topic page → Key definitions → 6 “What is activity?”, 7 “What is count-rate?” and 8 “What is half-life?”
- Draw: Key Diagrams: Atomic Structure → diagram 44 (half-life graph) 🔍 and diagram 45 (Geiger-Muller tube) 🔍.
- Copy worked example: Fill the gaps: Atomic Structure → passage 12 (half-life calculation: 800 Bq with a 2-hour half-life) – copy it with the answers filled in.
- Fill the gaps: passage 6 (activity and half-life).
- Practise: the half-life questions on Radioactive Decay and Half-life.
Lesson 6 – Hazards: contamination and irradiation (C+S)
- Copy notes: Radioactive Decay and Half-life → the contamination vs irradiation part of the copy box.
- Copy definition: Atomic structure topic page → Key definitions → 13 “Contamination vs irradiation”.
- See examples: 🔍 contamination and irradiation.
- Fill the gaps: Fill the gaps: Atomic Structure → passage 7 (contamination and irradiation) and passage 11 (radiation safety).
- Practise: the hazard questions on Radioactive Decay and Half-life.
- Lesson activity: Hospital Radiation Officer.
Lesson 7 – Background radiation and uses of radiation (S only)
- Read and copy notes: Hazards, Uses, Fission and Fusion → “Background radiation”, “Half-life and hazard” and “Uses in medicine”, plus the first two points of the copy box.
- Copy definition: Atomic structure topic page → Key definitions → 14 “What is background radiation?”
- See examples: 🔍 sources of background radiation and 🔍 medical tracers.
- Fill the gaps: Fill the gaps: Atomic Structure → passage 8 (background radiation and uses).
- Copy worked example: Hazards, Uses, Fission and Fusion → Q8 (evaluating radiation in medicine – note the benefits / risks / judgement structure).
- Practise: same page → Q1, Q2, Q6 and Q7.
Lesson 8 – Nuclear fission and fusion (S only)
- Read and copy notes: Hazards, Uses, Fission and Fusion → “Nuclear fission” and “Nuclear fusion”, plus the rest of the copy box.
- Copy definitions: Atomic structure topic page → Key definitions → 15 “Nuclear fission”, 16 “Chain reaction” and 17 “Nuclear fusion”.
- Draw: Key Diagrams: Atomic Structure → diagram 46 (fission chain reaction) 🔍 and diagram 47 (fusion) 🔍.
- Fill the gaps: Fill the gaps: Atomic Structure → passage 9 (fission and fusion).
- Practise: Hazards, Uses, Fission and Fusion → Q3, Q4 and Q5.
- Lesson activity: Power of the Future.
Lesson 9 – Review and test (C+S)
- Read: Atomic structure topic page → “⚠️ Where students lose marks”. Copy the three you think you’d get wrong.
- Test yourself: Atomic structure topic page → cover the answers and try all 17 Key definitions (Combined: 1–13 only).
- Mind map: Mind map guide → Atomic structure.
- Redraw from memory: diagrams 38, 40 and 42 from Key Diagrams: Atomic Structure, then check them.
- Quiz: Atomic structure quiz – 20 questions. Mark it and work out your percentage.
- Exam practice: AQA past papers → Paper 1 atomic structure questions.