Which statement about the radioactive decay of the nuclei in a sample of carbon-14 is correct?
The probability of an individual nucleus decaying per second increases as the nucleus ages.
The probability of any given undecayed nucleus decaying in a specific ten-minute interval is the same for all carbon-14 nuclei in the sample.
The activity of the sample remains constant over time because the decay constant is constant.
The decay constant of the remaining nuclei decreases over time as the sample becomes more stable.
484 exam-style questions on CIE IGCSE Physics 5.2 Radioactivity, covering 5.2.1 Background radiation and measuring count rate, 5.2.2a Alpha, beta and gamma emission, 5.2.2b Deflection and ionising effects of nuclear radiation, 5.2.3a Radioactive decay, 5.2.3b Effects of decay on the nucleus and decay equations, 5.2.4a Half-life, 5.2.4b Choosing isotopes for applications, and 5.2.5 Effects of ionising radiation and safety precautions. Each one has a worked solution and a mark scheme showing where the marks go.