A sample of a radioactive isotope is undergoing decay. Which of the following statements correctly describes this decay process?
Radioactive decay is random and spontaneous, meaning it is impossible to predict which specific nucleus will decay next.
The oldest nuclei in the sample are always the first to decay.
External factors such as temperature or pressure can be used to speed up the decay of the nuclei.
The nuclei at the surface of the sample will decay first because they are less shielded.
120 exam-style questions on CIE IGCSE Physics 5.2.3a Radioactive decay. Each one has a worked solution and a mark scheme showing where the marks go.