Photo AI
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 the human body. Exposure to radiation can cause cell damage and increase the risk of cancers, particularly if the contamination is significant and prolonged. Additionally, radioactive materials can accumulate in the body's tissues, leading to chronic health issues and disorders affecting organ function.
Step 2
Explain why some food is irradiated with gamma radiation.
Answer
Some food is irradiated with gamma radiation to kill harmful bacteria, parasites, and pests. This process extends shelf life by reducing spoilage and enhances food safety without significant loss of nutritional value. Gamma irradiation effectively sterilizes food, making it safer for consumption, particularly in areas with limited food preservation options.
Step 3
State how the nucleus does change when it emits a gamma ray.
Answer
When a nucleus emits a gamma ray, it transitions from a higher energy state to a lower energy state. While the number of protons and neutrons remains unchanged, the emission results in the release of excess energy, stabilizing the nucleus.
Step 4
Compare the processes of alpha decay and beta decay.
Answer
Alpha decay involves the emission of an alpha particle, which is composed of two protons and two neutrons (a helium nucleus). This process decreases the atomic number of the nucleus by 2 and the mass number by 4. In contrast, beta decay involves the transformation of a neutron into a proton, emitting a beta particle (an electron or positron). This increases the atomic number by 1 while keeping the mass number unchanged. Thus, alpha decay reduces the size of the nucleus significantly, while beta decay alters its composition without affecting its mass.