A scientist is observing a sample of an unstable radioactive isotope.
Which of the following statements best describes when an individual nucleus in the sample will undergo decay?
It is impossible to predict exactly when any specific nucleus will decay because radioactive decay is a random and spontaneous process.
The nuclei that have existed in the sample for the longest time are guaranteed to decay first.
Nuclei located on the outer surface of the sample decay before those deep inside the sample.
The decay of an individual nucleus can be accelerated by increasing the temperature or pressure on the sample.
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.