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Sometimes food can become contaminated with radioactive substances - Edexcel - GCSE Physics Combined Science - Question 6 - 2021 - Paper 1
Question 6
Sometimes food can become contaminated with radioactive substances. Describe the harmful effects of eating food contaminated with radioactive substances. (a) Gamm... show full transcript
Worked Solution & Example Answer:Sometimes food can become contaminated with radioactive substances - Edexcel - GCSE Physics Combined Science - Question 6 - 2021 - Paper 1
Step 1
Describe the harmful effects of eating food contaminated with radioactive substances.
Answer
Eating food contaminated with radioactive substances can have severe detrimental effects on health. Radioactive materials within food can emit radiation inside the body. This radiation can damage body cells and tissues, potentially leading to radiation sickness. Moreover, prolonged exposure to such radiation may increase the risk of developing cancer over time due to cellular mutations caused by the radiation.
Step 2
Explain why some food is irradiated with gamma radiation.
Answer
Some food is irradiated with gamma radiation primarily to preserve it and enhance its shelf life. The gamma rays penetrate deeply and effectively kill off bacteria and pathogens that may cause spoilage, while also preventing the reproduction of microorganisms. This process helps in stopping food from going off, making it safer for consumption.
Step 3
State how the nucleus does change when it emits a gamma ray.
Answer
When the nucleus emits a gamma ray, it changes in energy state. The emission does not alter the number of protons or neutrons in the nucleus, but it results in a nucleus that is at a lower energy level, which can be more stable than the original nucleus.
Step 4
Compare the processes of alpha decay and beta decay.
Answer
Alpha decay involves the emission of an alpha particle, which contains two protons and two neutrons (like a helium nucleus). This process reduces the original nucleus's mass number by four and its atomic number by two, thereby transforming it into a different element. In contrast, beta decay involves the conversion of a neutron into a proton and an electron. This process increases the atomic number by one without changing the mass number, also resulting in a different element. Therefore, alpha decay lowers the atomic number, while beta decay raises it.