Radioactivity
Overview
Radioactivity is the spontaneous emission of radiation from unstable atomic nuclei. It underpins everything from medical imaging and cancer treatment to smoke detectors and carbon dating.
In this lesson you will learn about atomic structure, isotopes, the three types of nuclear radiation (alpha, beta and gamma), how to balance nuclear equations, half-life calculations, uses and dangers of radiation, and the difference between contamination and irradiation.
Objectives
- Describe the structure of an atom in terms of protons, neutrons and electrons and use standard notation to describe particular nuclei
- Know the terms: atomic (proton) number, mass (nucleon) number and isotope
- Know that alpha particles, beta particles and gamma rays are ionising radiations emitted from unstable nuclei in a random process
- Describe the nature of alpha particles, beta particles and gamma rays and recall that they may be distinguished in terms of penetrating power and ability to ionise
- Investigate the penetration powers of different types of radiation
- Describe the effects on the atomic and mass numbers of a nucleus of the emission of each of the four main types of radiation
- Understand how to balance nuclear equations in terms of mass and charge
- Know that photographic film or a Geiger-Muller detector can detect ionising radiations
- Explain the sources of background (ionising) radiation from Earth and space
- Know that the activity of a radioactive source decreases over a period of time and is measured in becquerels
- Know the definition of the term half-life and understand that it is different for different radioactive isotopes
- Use the concept of half-life to carry out simple calculations on activity, including graphical methods
- Describe uses of radioactivity in industry and medicine
- Describe the difference between contamination and irradiation
- Describe the dangers of ionising radiations, including mutations, cell damage and radioactive waste disposal
Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Radioactivity. 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.
- Alpha particles are stopped by: A) Concrete B) Aluminium C) Paper D) Nothing Answer: C
- In beta decay, the atomic number: A) Decreases by 2 B) Stays the same C) Increases by 1 D) Decreases by 1 Answer: C
- The most ionising radiation is: A) Alpha B) Beta C) Gamma D) X-rays Answer: A
- Half-life is the time for: A) All atoms to decay B) Activity to reach zero C) Activity to halve D) Temperature to halve Answer: C
- Contamination differs from irradiation because: A) It involves gamma only B) Radioactive material is on/in the body C) It does not involve radiation D) It stops when the source is removed Answer: B
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Practice Mock Questions
Want to practice mock questions on Radioactivity? Download the Green Bridge CBT app to access mock questions and full practice assessments for this topic.
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