In a commercial packing house, fresh strawberries are exposed to high-energy gamma radiation to extend their shelf-life.
Explain the difference between nuclear irradiation and nuclear contamination in this context.
Explain how the gamma radiation prevents the strawberries from spoiling so quickly.
Some consumers are hesitant to buy irradiated fruit because they worry it might be radioactive. Explain why irradiated strawberries are entirely safe to consume and do not emit nuclear radiation.
Cesium-137 is a common source of gamma radiation used in industrial irradiators. Cesium has two different isotopes, cesium-133 and cesium-137. Both isotopes have 55 protons in their nucleus.
Cesium-137 is radioactive and cesium-133 is stable. Explain why some isotopes are radioactive.
Describe how the nucleus of cesium-133 is different from the nucleus of cesium-137.
Decay equations are used to show the type of emission from different radioactive elements.
Complete the decay equation for alpha emission:
84210Po→24He+⋯⋯⋯⋯Pb {}^{210}_{84}\text{Po} \rightarrow {}^{4}_{2}\text{He} + {}^{\cdots\cdots}_{\cdots\cdots}\text{Pb} 84210Po→24He+⋯⋯⋯⋯PbComplete the decay equation for beta emission:
13H→⋯⋯⋯⋯β+23He {}^{3}_{1}\text{H} \rightarrow {}^{\cdots\cdots}_{\cdots\cdots}\beta + {}^{3}_{2}\text{He} 13H→⋯⋯⋯⋯β+23HeComplete the decay equation for gamma emission:
⋯⋯⋯⋯Ba→00γ+56137Ba {}^{\cdots\cdots}_{\cdots\cdots}\text{Ba} \rightarrow {}^{0}_{0}\gamma + {}^{137}_{56}\text{Ba} ⋯⋯⋯⋯Ba→00γ+56137Ba13 exam-style questions on OCR GCSE Physics Uses and hazards. Each one has a worked solution and a mark scheme showing where the marks go.