A sample contains 600 mg of a radioactive isotope. The half-life of the isotope is 8 days8\text{ days}8 days. What mass of this radioactive isotope remains after 24 days24\text{ days}24 days?
0 mg0\text{ mg}0 mg
75 mg75\text{ mg}75 mg
150 mg150\text{ mg}150 mg
300 mg300\text{ mg}300 mg
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.