Physics: Radioactivity And Particles: Units
Overview
Radioactivity is invisible, silent and completely beyond the reach of your senses. The only way to say anything useful about a radioactive source is to attach numbers to it, and numbers in physics are worthless without the right units.
This short lesson covers the handful of units you need for the whole radioactivity topic: the becquerel for activity, the centimetre for the distances and thicknesses used in absorption experiments, and the second, minute and hour for the times that appear in half-life questions. You will also practise the conversions that examiners build into calculation questions.
Objectives
- Use the following units: becquerel (Bq), centimetre (cm), hour (h), minute (min) and second (s)
Mind map
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Flashcards
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Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Physics: Radioactivity And Particles: Units. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- The becquerel is the unit of: A) Half-life B) Activity C) Absorbed dose D) Count rate in a detector Answer: B
- An activity of 1 Bq means: A) One decay per minute B) One decay per hour C) One decay per second D) One thousand decays per second Answer: C
- A source has an activity of 2.5 kBq. In becquerels this is: A) 25 Bq B) 250 Bq C) 2500 Bq D) 25000 Bq Answer: C
- A detector records 600 counts in 5 minutes. The count rate in counts per second is: A) 2 counts per second B) 120 counts per second C) 12 counts per second D) 0.5 counts per second Answer: A
- An absorber is 6 mm thick. In centimetres this is: A) 0.06 cm B) 0.6 cm C) 6 cm D) 60 cm Answer: B
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Practice Mock Questions
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