Pearson Edexcel International GCSE in Physics · 4PH1 · Free · no account needed
Topic 7 · Radioactivity and particles
Inside the nucleus: alpha, beta and gamma radiation, nuclear equations, half-life, background radiation, the dangers and uses, and fission and fusion.
Every lesson here ends the same way: learn it, teach it to an AI pupil who asks the awkward question, then defend it against the thinker with the strongest claim on it — free · no account needed.
9 lessons, covering 26 specification statements.
What you need to know — the 26 statements, and where each one is taught
Every statement this topic carries, in the specification's own numbering, with Incandio's restatement of what it asks and the lesson that discharges it. Tick them off against your own copy of the specification: this is the topic's revision checklist, not a summary of it. 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 statement numbers are given so you can check every lesson against your own copy.
| Statement | What it asks | Taught in |
|---|---|---|
| 7.1 | Use the units becquerel, centimetre, hour, minute and second | Atomic Structure and Isotopes |
| 7.2 | The structure of an atom in terms of protons, neutrons and electrons, and nuclide symbols | Atomic Structure and Isotopes |
| 7.3 | The terms atomic number, mass number and isotope | Atomic Structure and Isotopes |
| 7.4 | Alpha, beta and gamma as ionising radiations emitted at random from unstable nuclei | Alpha, Beta and Gamma |
| 7.5 | The nature of alpha, beta and gamma, and how they differ in penetration and ionisation | Alpha, Beta and Gamma |
| 7.6 (practical) | Practical: investigate the penetrating power of different types of radiation | Alpha, Beta and Gamma |
| 7.7 | The effect of alpha, beta, gamma and neutron emission on atomic and mass number | Nuclear Equations |
| 7.8 | Balancing nuclear equations in terms of mass and charge | Nuclear Equations |
| 7.9 | Photographic film and the Geiger–Müller detector as detectors of ionising radiation | Detecting Radiation and Background |
| 7.10 | The sources of background radiation from Earth and space | Detecting Radiation and Background |
| 7.11 | Activity decreases over time and is measured in becquerels | Half-Life |
| 7.12 | The definition of half-life, and that it differs between isotopes | Half-Life |
| 7.13 | Half-life calculations, including graphical methods | Half-Life |
| 7.14 | Uses of radioactivity in industry and medicine | Uses and Dangers of Radiation |
| 7.15 | The difference between contamination and irradiation | Uses and Dangers of Radiation |
| 7.16 | The dangers of ionising radiation and the problems of radioactive waste disposal | Uses and Dangers of Radiation |
| 7.17 | Fission, fusion and radioactive decay as sources of energy | Nuclear Fission |
| 7.18 | How a U-235 nucleus is split by a neutron, releasing kinetic energy | Nuclear Fission |
| 7.19 | Fission of U-235 produces two radioactive daughter nuclei and a few neutrons | Nuclear Fission |
| 7.20 | How a chain reaction is set up | Chain Reactions and Reactors |
| 7.21 | The role of control rods and the moderator | Chain Reactions and Reactors |
| 7.22 | The role of shielding around a nuclear reactor | Chain Reactions and Reactors |
| 7.23 | The difference between nuclear fusion and nuclear fission | Nuclear Fusion |
| 7.24 | Fusion as the creation of larger nuclei with a loss of mass and a release of energy | Nuclear Fusion |
| 7.25 | Fusion as the energy source for stars | Nuclear Fusion |
| 7.26 | Why fusion does not happen at low temperatures and pressures | Nuclear Fusion |
The lessons
- Atomic Structure and Isotopes — A nucleus ten thousand times smaller than the atom around it, and why two atoms of the same element can weigh different amounts. (7.1, 7.2, 7.3)
- Alpha, Beta and Gamma — Three emissions from unstable nuclei, arriving at random — and why the one that is easiest to stop is the one to be most careful with. (7.4, 7.5, 7.6)
- Nuclear Equations — What each kind of decay does to the numbers — and why losing a negative particle makes the charge go up. (7.7, 7.8)
- Detecting Radiation and Background — How you measure something invisible, and why the counter clicks even with no source in the room. (7.9, 7.10)
- Half-Life — Half of what is left, every time — which is why a radioactive sample never quite runs out. (7.11, 7.12, 7.13)
- Uses and Dangers of Radiation — Choosing a source by its half-life and its penetration — and the difference between being irradiated and being contaminated. (7.14, 7.15, 7.16)
- Nuclear Fission — A single neutron splits a nucleus in half, and the pieces weigh less than what you started with. (7.17, 7.18, 7.19)
- Chain Reactions and Reactors — Two or three neutrons from every split — and the two entirely different jobs a reactor does to them. (7.20, 7.21, 7.22)
- Nuclear Fusion — How the Sun works, and why it is so hard to make it happen anywhere else. (7.23, 7.24, 7.25, 7.26)