Question 1: Define alpha radiation and describe its properties including charge, mass, and penetrating ability.

Answer: Alpha radiation consists of helium nuclei (2 protons and 2 neutrons), carries a +2 charge, has a relatively large mass, and has low penetrating ability, being stopped by paper or skin.

Question 2: Explain how beta particles are produced in radioactive decay and their typical penetrating power.

Answer: Beta particles are high-energy electrons or positrons emitted when a neutron turns into a proton or vice versa within an unstable nucleus. They have moderate penetrating power, able to pass through paper but stopped by metal sheets.

Question 3: What is gamma radiation, and why is it considered highly penetrating?

Answer: Gamma radiation is electromagnetic radiation emitted from the nucleus during radioactive decay. It is highly penetrating because it has very short wavelengths and no mass or charge.

Question 1: A sample of uranium-238 undergoes alpha decay. What is the atomic number and mass number of the resulting daughter nucleus?

Answer: Atomic number: 90, Mass number: 234

Question 2: If a radioactive source emits 500 alpha particles per minute, how many alpha particles are emitted per second? (Show calculation)

Answer: 8.33 alpha particles per second (500 ÷ 60)

Question 3: Calculate the activity in becquerels (Bq) of a sample that emits 1200 gamma photons every 10 seconds.

Answer: 120 Bq (1200 ÷ 10)

Question 1: Describe a basic safety protocol when handling radioactive sources in a laboratory setting.

Answer: Use shielding materials such as lead or concrete, wear protective gloves and glasses, limit exposure time, and keep radioactive sources in designated containers.

Question 2: Identify the variables that could affect the intensity of radiation detected from a radioactive source.

Answer: Distance from the source, thickness of shielding, type of radiation emitted, and the activity level of the source.

Question 1: A radioactive sample measured at 200 counts per minute (CPM) at 10 cm distance. When moved to 20 cm, the counts drop to 50 CPM. Explain what this data suggests about the relationship between distance and radiation intensity.

Answer: The counts decrease as the distance increases, indicating an inverse square relationship between distance and radiation intensity, consistent with the inverse square law.

Question 2: A sample's activity is measured at 600 Bq. After one half-life, what will be its activity? Assume the half-life is 24 hours.

Answer: 300 Bq, since activity halves after each half-life.

Question 3: A patient is exposed to a source emitting gamma radiation. Explain why gamma rays pose a higher risk to the body compared to alpha or beta particles.

Answer: Gamma rays are highly penetrating electromagnetic radiation capable of passing through human tissue and organs, potentially damaging cells and DNA deep within the body. In contrast, alpha particles are stopped by skin or clothing, and beta particles are stopped by thin metal sheets, making gamma radiation more dangerous for internal exposure.

Question 1: Describe one application of gamma radiation in medicine.

Answer: Gamma rays are used in cancer radiotherapy to target and destroy cancerous cells.

Question 2: Explain how alpha emitters are used in smoke detectors.

Answer: Alpha emitters like americium-241 ionize air particles, and changes in ionization levels are used to detect smoke, triggering the alarm.