This question is about radioactivity - Edexcel - GCSE Physics - Question 3 - 2021 - Paper 1
Question 3
This question is about radioactivity.
(a) Alpha (α), beta (β) and gamma (γ) are three types of radioactive emissions.
Which statement describes all of these radioac... show full transcript
Worked Solution & Example Answer:This question is about radioactivity - Edexcel - GCSE Physics - Question 3 - 2021 - Paper 1
Step 1
Which statement describes all of these radioactive emissions?
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Answer
The correct statement is B: ionising and emitted by unstable nuclei. Alpha, beta, and gamma radiation all involve emissions from unstable atomic nuclei, which are ionising radiation types.
Step 2
Describe one similarity between the numbers of particles in one nucleus of fluorine-19 and one nucleus of a radioactive isotope of fluorine.
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Answer
Both fluorine-19 and a radioactive isotope of fluorine share the same number of protons, which is 9, as they are isotopes of the same element.
Step 3
Describe one difference between the numbers of particles in one nucleus of fluorine-19 and one nucleus of a radioactive isotope of fluorine.
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Answer
The difference lies in the number of neutrons; fluorine-19 has 10 neutrons, while a radioactive isotope may have a different number of neutrons, resulting in a different mass number.
Step 4
Explain why the new count is greater than 268.
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Answer
The new count is greater than 268 because removing the aluminium sheet allows more beta particles to reach the Geiger-Muller tube. The sheet absorbs some beta radiation, so without it, more radiation is detected.
Step 5
Give a reason why there would be no reading on the counter.
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There would be no reading on the counter because the beta source has been removed, and without the source, there are no beta particles to detect.
Step 6
State the SI unit for the activity of a radioactive source.
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The SI unit for the activity of a radioactive source is the becquerel (Bq).
Step 7
Calculate the number of radium-223 nuclei remaining in the source after a time of 33 days.
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Answer
Since the half-life of radium-223 is 11 days, 33 days corresponds to 3 half-lives. Starting with 1.7 × 10²³ nuclei, the calculation is as follows:
