Question 1: Define alpha radiation and describe its properties.

Answer: Alpha radiation consists of helium nuclei (2 protons and 2 neutrons); it has a positive charge, low penetration ability, and is stopped by paper or skin.

Question 2: Explain how beta particles are different from alpha particles in terms of their mass and charge.

Answer: Beta particles are fast-moving electrons or positrons with much smaller mass than alpha particles and carry a negative or positive charge respectively.

Question 3: What type of radiation has the highest penetration ability? Explain why.

Answer: Gamma radiation has the highest penetration ability because it consists of electromagnetic waves with very high energy and no mass.

Question 4: Describe the mechanism by which gamma radiation interacts with matter.

Answer: Gamma rays interact with matter mainly through photoelectric effect, Compton scattering, and pair production, transferring energy to atoms and molecules.

Question 1: A sample of radioactive iodine-131 has a half-life of 8 days. How much of a 100 g sample remains after 24 days? (Use the formula: Remaining amount = initial amount × (1/2)^(time/half-life)).

Answer: 12.5 grams

Question 2: If a gamma ray photon has an energy of 1 MeV, what is its wavelength? (Use the formula: wavelength = speed of light / frequency; with E = hf and c = λf). Take c = 3 × 10^8 m/s, h = 6.626 × 10^-34 Js, 1 eV = 1.602 × 10^-19 J, so 1 MeV = 1.602 × 10^-13 J.

Answer: approximately 1.24 × 10^-12 meters

Question 1: List three safety precautions to take when handling radioactive materials in a laboratory setting.

Answer: Use shielding to block radiation, wear protective gloves and clothing, and minimize exposure time.

Question 2: Describe a simple experiment to detect alpha radiation using a piece of paper and a Geiger counter.

Answer: Place a radioactive source near the Geiger counter with a piece of paper in between. If the counter detects radiation through the paper, it confirms alpha particles are being emitted, as they are stopped by paper but can be detected beyond it.

Question 1: A hospital uses radioactive isotopes for medical imaging. Explain how gamma radiation is used in this context and why it is preferred over alpha or beta radiation.

Answer: Gamma radiation is used because it can penetrate body tissues to produce images without damaging the patient’s cells significantly. Its high penetration ability allows for clear imaging, unlike alpha or beta particles which are stopped by body tissues.

Question 2: Identify an industry where radioactive isotopes are used for quality control and explain how radioactivity helps in this process.

Answer: In the oil industry, radioactive isotopes are used in well logging to measure the density of rock formations, helping to identify oil deposits by detecting gamma rays emitted from the formation.