Iodine-131 is radioactive. It has a half-life of 8.0 days.
The nuclide notation for iodine-131 is 53131I^{131}_{53}\text{I}53131I.
State the composition of the nucleus of iodine-131.
Iodine-131 decays by β\betaβ-decay to an isotope of xenon, Xe\text{Xe}Xe.
Complete the equation for the decay of iodine-131:
53131I→‾β+‾Xe ^{131}_{53}\text{I} \rightarrow \underline{\quad\quad} \beta + \underline{\quad\quad} \text{Xe} 53131I→β+XeThe count rate from a sample of iodine-131 is 480 counts/s480\text{ counts/s}480 counts/s.
Predict the count rate from the sample after 24 days.
State two social, economic, or environmental issues involved in the storage of radioactive waste materials with very long half-lives.
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.