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Physics notebook Cambridge IGCSE 0625

Topic 5 of 6 · 3 modules planned

Nuclear physics

What is inside the nucleus, why some nuclei decay and how to use radiation safely.

Modules

  1. Module 1 · syllabus 5.1.1, 5.1.2

    Inside the nucleus

    How do we know an atom is mostly empty space?

    This module is planned. It will have readings, an experiment, practice with self-checks and a final check.

Syllabus statements for this topic · for teachers · 31 statements

Core for every pupil · Supplement also for Extended entry. Paraphrased from the Cambridge IGCSE Physics 0625 syllabus (2026–2028); check the official syllabus for exact wording.

5.1.1 The atom

  • 5.1.1.1Atom: positive nucleus with orbiting electronsC
  • 5.1.1.2Ions from losing or gaining electronsC
  • 5.1.1.3Alpha scattering as evidence for the nuclear modelS

5.1.2 The nucleus

  • 5.1.2.1Nucleus made of protons and neutronsC
  • 5.1.2.2Relative charges of proton, neutron and electronC
  • 5.1.2.3Proton number, nucleon number and neutron countC
  • 5.1.2.4Nuclide notationC
  • 5.1.2.5Isotopes of an elementC
  • 5.1.2.6Fission and fusion with nuclide equationsS
  • 5.1.2.7Proton number and nuclear chargeS
  • 5.1.2.8Nucleon number and nuclear massS

5.2.1 Detection of radioactivity

  • 5.2.1.1Background radiationC
  • 5.2.1.2Main sources of background radiationC
  • 5.2.1.3Detector and counter measure ionising radiationC
  • 5.2.1.4Count rate in counts per second or minuteC
  • 5.2.1.5Correcting a count rate for backgroundS

5.2.2 The three types of nuclear emission

  • 5.2.2.1Emission is spontaneous and random in directionC
  • 5.2.2.2Alpha, beta, gamma: nature, ionising and penetrationC
  • 5.2.2.3Deflection of alpha, beta and gamma in fieldsS
  • 5.2.2.4Ionising effect from kinetic energy and chargeS

5.2.3 Radioactive decay

  • 5.2.3.1Radioactive decay: unstable nucleus, random emissionC
  • 5.2.3.2Alpha or beta decay changes the elementC
  • 5.2.3.3Why isotopes are unstable: excess neutrons, sizeS
  • 5.2.3.4Effect of each decay type on the nucleusS
  • 5.2.3.5Decay equations in nuclide notationS

5.2.4 Half-life

  • 5.2.4.1Half-life and simple half-life calculationsC
  • 5.2.4.2Half-life from data including backgroundS
  • 5.2.4.3Choosing an isotope by radiation type and half-lifeS

5.2.5 Safety precautions

  • 5.2.5.1Harm from ionising radiation to living thingsC
  • 5.2.5.2Moving, using and storing sources safelyC
  • 5.2.5.3Safety by time, distance and shieldingS