Build the nuclear model
The nucleus contains protons and neutrons; electrons occupy regions around it. Isotopes have the same number of protons but different numbers of neutrons. Mass number counts nucleons, while atomic number counts protons.
GCSE Physics resources
AQA GCSE Atomic structure
AQA GCSE Atomic structure Revision
Atomic-structure questions combine a model of the atom, radiation properties and careful use of nuclear notation. Always distinguish irradiation from contamination.
Topic overview
Plan your atomic structure revision
Use the resource cards below to revise one idea at a time. Each page includes worked examples, mini quizzes, practice questions, exam language and a visual or simulation when it adds learning value.
Knowledge map
How the topic fits together
Use this overview to find the part of the topic that needs attention; the focused guides below teach and assess each idea in depth.
Compare the three radiations
Alpha is strongly ionising with a short range. Beta is moderately ionising with a medium range. Gamma is weakly ionising and highly penetrating. The exact choice of radiation depends on the application.
Use half-life safely
Half-life is the time for the activity or count rate of a sample to fall to half its value. Radioactive decay is random for individual nuclei, but the pattern is predictable for a large sample.
Focused revision
Choose one idea at a time
Each guide combines explanation, a diagnostic check, misconception repair, worked examples and exam-style practice.
AT-01
Atoms, Isotopes and Nuclear Notation
The top number is mass number and the bottom number is atomic number. Use them to find protons, neutrons and electrons in a neutral atom, then explain why isotopes have similar chemical properties.
AT-02
Alpha, Beta and Gamma Radiation
Use the linked properties: ionising power, range, penetration, deflection and practical use. Do not rank one radiation as simply “best”; explain why the property suits the context.
AT-03
Half-Life and Radioactive Decay
Half-life describes a repeated halving of activity or count rate. Correct for background radiation where needed, plot a decay curve and distinguish random individual decay from the predictable pattern of a large sample.
AT-04
Radiation Hazards, Contamination and Irradiation
Irradiation is exposure to radiation from a source; contamination is radioactive material getting onto or into an object. Ionising radiation can damage cells, so risk depends on dose, time, distance, shielding and the source.
Across every topic
Build the exam skills around the physics
AQA GCSE Physics Required PracticalsLearn the method, diagnose errors and practise it.GCSE Physics Equations and Maths SkillsLearn the method, diagnose errors and practise it.How to Answer GCSE Physics Calculation QuestionsLearn the method, diagnose errors and practise it.How to Answer GCSE Physics Six-Mark QuestionsLearn the method, diagnose errors and practise it.GCSE Physics Graph SkillsLearn the method, diagnose errors and practise it.
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