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9 (a) Sometimes food can become contaminated with radioactive substances - Edexcel - GCSE Physics - Question 9 - 2021 - Paper 1
Question 9
9 (a) Sometimes food can become contaminated with radioactive substances. Describe the harmful effects of eating food contaminated with radioactive substances. (b) ... show full transcript
Worked Solution & Example Answer:9 (a) Sometimes food can become contaminated with radioactive substances - Edexcel - GCSE Physics - Question 9 - 2021 - Paper 1
Step 1
Describe the harmful effects of eating food contaminated with radioactive substances.
Answer
Eating food contaminated with radioactive substances can lead to various harmful effects on human health. The primary concern is radiation exposure, which can result in cellular damage, increasing the risk of cancer. Prolonged exposure may also cause acute radiation syndrome, which is characterized by symptoms like nausea, vomiting, and fatigue.
Step 2
Explain why some food is irradiated with gamma radiation.
Answer
Food is irradiated with gamma radiation to eliminate harmful bacteria and pests, thereby enhancing food safety and preservation. This process extends the shelf life of food products while maintaining their nutritional quality. Gamma radiation effectively kills microorganisms without significantly heating the food.
Step 3
State how the nucleus does change when it emits a gamma ray.
Answer
When a nucleus emits a gamma ray, it releases energy without changing the number of protons or neutrons. The emission of gamma radiation typically occurs after other types of radioactive decay, allowing the nucleus to reach a more stable energy state.
Step 4
Compare the processes of alpha decay and beta decay.
Answer
Alpha decay involves the emission of an alpha particle, which consists of 2 protons and 2 neutrons, resulting in a new element with an atomic number decreased by 2 and a mass number decreased by 4. Beta decay involves the conversion of a neutron into a proton, emitting a beta particle (electron); this process increases the atomic number by 1 but does not change the mass number. Therefore, alpha decay reduces both the atomic and mass numbers, while beta decay increases the atomic number and leaves the mass number unchanged.