A radioactive source is positioned in front of a radiation detector. When a thin sheet of paper is placed between them, the count rate remains high. However, when the sheet of paper is replaced by a 5 mm thick sheet of aluminium, the count rate drops to near background levels.
From this result, which type of radiation is the source primarily emitting?
α\alphaα-particles
β\betaβ-particles
γ\gammaγ-rays
X-rays
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.