Question 1: Explain in your own words what alpha, beta, and gamma radiation are, including their origin in radioactive decay.

Answer: Alpha particles are helium nuclei emitted during decay, beta particles are high-energy electrons or positrons, and gamma rays are high-frequency electromagnetic waves; all originate from unstable atomic nuclei during radioactive decay processes.

Question 2: Identify which type of radiation (alpha, beta, gamma) is most penetrating and which is the least penetrating.

Answer: Gamma radiation is the most penetrating, while alpha radiation is the least penetrating.

Question 1: Describe the mechanism by which alpha particles are emitted during radioactive decay.

Answer: Alpha particles are emitted when an unstable nucleus releases a helium nucleus to become more stable, reducing its atomic number by 2 and mass number by 4.

Question 2: What safety precautions are necessary when handling sources that emit beta radiation in industrial settings?

Answer: Use lead or plastic shielding, wear protective clothing and gloves, minimise exposure time, and maintain a safe distance from the source.

Question 1: A radioactive isotope used in industry has a half-life of 24 hours. How much of a 100 g sample remains after 72 hours? (Use the formula: Remaining amount = initial amount × (1/2)^{time / half-life})

Answer: 12.5 g

Question 2: Calculate the activity (in becquerels) of a sample that emits 5 radioactive decays per second per gram. The sample mass is 50 grams.

Answer: 250 Bq

Question 1: Design a basic experimental setup to measure the attenuation of gamma radiation through different materials. Describe the key variables you would control and safety measures you would implement.

Answer: The setup includes a gamma source, a detector, and various materials (e.g., lead, plastic). Variables include material thickness, distance from source to detector, and radiation intensity. Safety measures involve shielding the source, maintaining a safe distance, and wearing protective equipment.

Question 1: A gamma-ray source used in industrial radiography emits 10^6 gamma rays per second. If shielding reduces this by 99%, what is the remaining emission rate? How is this reduction important for safety?

Answer: 10,000 gamma rays per second; this reduction significantly decreases radiation exposure risk to workers and the environment.

Question 2: Explain how gamma radiation is utilised in sterilising medical equipment and the benefits it provides in industrial chemistry.

Answer: Gamma radiation is used to irradiate medical tools and packaging materials, killing bacteria and viruses without heat or chemicals. This method ensures sterile equipment, reduces contamination, and enhances safety in industrial and healthcare settings.