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.
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.