Which statement correctly describes the nature of radioactive decay for a sample of unstable nuclei?
The rate of decay can be significantly increased by raising the temperature of the sample.
The process is random and spontaneous, so it is impossible to predict exactly when an individual nucleus will decay.
The decay only affects the outer-shell electrons of the atom, leaving the nucleus unchanged.
The individual nuclei always decay in a fixed, predictable sequence.
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.