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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. Gamma rad... 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 lead to several harmful effects. First, radioactive materials in the food can emit radiation inside the body, leading to internal exposure to radioactivity. This exposure can cause damage to body cells, potentially leading to mutations and various health issues, including cancer. Moreover, these substances can accumulate in the body, posing long-term health risks.
Step 2
Explain why some food is irradiated with gamma radiation.
Answer
Some food is irradiated with gamma radiation to preserve its quality and extend its shelf life. The gamma rays penetrate deeply into the food, effectively killing bacteria and other pathogens that can lead to spoilage. This process also helps sterilize the food, ensuring it is safe for consumption while maintaining its nutritional value.
Step 3
State how the nucleus does change when it emits a gamma ray.
Answer
When the nucleus emits a gamma ray, it undergoes a transition to a lower energy state. However, the emission does not alter the number of protons or neutrons in the nucleus; instead, the overall energy level of the nucleus decreases.
Step 4
Compare the processes of alpha decay and beta decay.
Answer
Alpha decay involves the emission of an alpha particle, which is made up of 2 protons and 2 neutrons (essentially a helium nucleus). This process reduces the original nucleus's atomic number by 2 and mass number by 4, leading to the formation of a new nucleus. In contrast, beta decay involves the transformation of a neutron into a proton with the emission of a beta particle (an electron). This increases the atomic number by 1 while the mass number remains unchanged, resulting in a different element.