Home / G3 Science (Physics) / Radioactivity / Check what I know: Radioactivity · G3 Science Physics Exit to Radioactivity Check what I know: Radioactivity · G3 Science Physics Check what you know about Radioactivity, practise what needs work, then check your progress and return for a later review within the G3 Science syllabus.
Learning goals Work through the questions and use the feedback to plan revision. What this check covers: This check samples the required Radioactivity capabilities. It routes focused practice and does not itself establish mastery. Your answers help choose what to revise next.Check what I know
Check what I know: Radioactivity · G3 Science Physics A text-first Radioactivity assessment with nuclide numbers, emissions, detector readings, units, application contexts and safety conditions stated explicitly.
About 8 minutes
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Answer 6 short questions. This starting check helps choose what to work on; it does not prove mastery.
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Oxygen-16 and oxygen-18 are neutral atoms with proton number 8. Which statement gives their structure and isotope relationship correctly?
Each has 8 protons and 8 electrons; their positive nuclei also contain 8 and 10 neutrons, so they are isotopes with nucleon numbers 16 and 18. Each nucleus contains 8 electrons; the atoms are isotopes because their electron numbers match. They have 16 and 18 protons, so they are different elements rather than isotopes. Each has 8 neutrons, but oxygen-18 has two extra electrons in its nucleus. A sodium nuclide has nucleon number A = 23, proton number Z = 11 and element symbol Na. Where should the two numbers be placed in nuclide notation?
23 at the upper left of Na and 11 at the lower left. 11 at the upper left of Na and 23 at the lower left. 23 at the upper right of Na and 11 at the lower left. 23 at the upper left of Na and 11 at the lower right. Which observation correctly describes radioactive decay as both random and spontaneous?
No one can predict the decay time of one unstable nucleus, and the decay needs no heating, collision or other external trigger. Every sample loses the same number of nuclei each second after it is heated. All unstable nuclei decay immediately, but in different directions. Large samples show no trend because every decay is unpredictable. Which comparison of alpha, beta-minus and gamma radiation is complete and correct?
Alpha is a helium nucleus and is most ionising but least penetrating; beta-minus is a fast electron with intermediate effects; gamma is electromagnetic radiation and is least ionising but most penetrating. Alpha is electromagnetic radiation, beta-minus is a neutron, and gamma is a helium nucleus. Gamma is most ionising and least penetrating because it has no charge. All three are charged particles with equal ionising effect but different speeds. A detector reads 340 counts/min with a source and 20 counts/min without it. After 6 hours the source has passed through two half-lives. What is background radiation and what measured reading is then expected on average?
Background is environmental ionising radiation present without the source; the expected measured reading is 100 counts/min. Background is radiation stored in the detector; the reading is 85 counts/min. Background is the source's gamma component; the reading is 80 counts/min. Background is random detector error; the reading is 180 counts/min. Which statement justifies radioactive sources in both medicine and industry while recognising their hazard?
A medical tracer may emit penetrating gamma detectable outside the body, while a thickness gauge uses changing detector count; both require suitable half-life, containment and controlled time, distance and shielding because ionising radiation can damage cells. Alpha is always best for internal tracers and unshielded factory gauges because it is most penetrating. Any source works indefinitely if it is sealed, because sealing removes irradiation. Radioactive sources are useful only because they heat materials, so distance and shielding are unnecessary. Practise
Practise: Radioactivity · G3 Science Physics A text-first Radioactivity assessment with nuclide numbers, emissions, detector readings, units, application contexts and safety conditions stated explicitly.
About 10 minutes
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Questions are selected when you start. Use the feedback to decide what to practise next; this does not prove mastery.
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Practise
Practise after feedback: Radioactivity · G3 Science Physics A text-first Radioactivity assessment with nuclide numbers, emissions, detector readings, units, application contexts and safety conditions stated explicitly.
About 10 minutes
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Questions are selected when you start. Use the feedback to decide what to practise next; this does not prove mastery.
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Check my progress
Check my progress: Radioactivity · G3 Science Physics A text-first Radioactivity assessment with nuclide numbers, emissions, detector readings, units, application contexts and safety conditions stated explicitly.
About 10 minutes
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Answer 8 questions. If accepted, this result can contribute to your course progress.
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Check again
Check again: Radioactivity · G3 Science Physics A text-first Radioactivity assessment with nuclide numbers, emissions, detector readings, units, application contexts and safety conditions stated explicitly.
About 10 minutes
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Answer 8 questions. If accepted, this result can contribute to your course progress.
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Review
Review: Radioactivity · G3 Science Physics A text-first Radioactivity assessment with nuclide numbers, emissions, detector readings, units, application contexts and safety conditions stated explicitly.
About 10 minutes
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Answer 8 questions. A scheduled review can contribute to your course progress only when it is due and the result is accepted.
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Course and syllabus information Course SEC G3 Combined Science Physics component Edition SEC G3 Combined Science Physics component 2027